Building a Delta V Sailing Dinghy
Building a Delta V Sailing Dinghy
(If anyone has questions about boat building, don't hesitate to ask me.)
In late 2003 I started on a Delta V sailing dinghy from Northwest Marine Design. The Delta V is a design that conforms to the NS14 class, a development class mostly sailed in Australia. I thought long and hard about building a Swift Solo but eventually decided on the Delta V because I wasn't sure that I could handle a Swift Solo and the Swift Solo is too expensive to build unless you are really going to use it.
I did buy the construction manual for the Swift Solo, which was a good idea as it has a number of good ideas for sailboat building. I adapted many of the techniques there and also other techniques used in building the Swift Solo. The plans for the Delta V are not as detailed as I would have liked, and I didn't receive the page for the Delta V with the bulkheads. This actually worked out well in the end, as I got the offsets for the bulkheads from the designer, and this, along with the offsets on the plans, let me loft and print the building forms and the bulkhead templates using an HP plotter.
The plans for the Delta V specify plywood deck, cockpit, and bulkheads. I decided to strip everything, because a stripped deck, cockpit, and transom look much nicer than plywood, and then I may as well strip the interior bulkheads using the poorer-quality strips. I only needed to bead-and-cove the hull, as the deck is quite flat and the cockpit and bulkheads are absolutely flat.
Stripping everything means that I had to glass both sizes of the bulkheads, cockpit, and deck, which I decided to do using 9-ounce S-glass. This is the first time I used S-glass, and I bought a high-thread-count (57x54, I think) 9-ounce 8-harness satin weave S-glass from J. R. Sweet. (I bought the last 43 yards of this material that they had, in a combination of 50-inch wide and 60-inch wide material.) This glass was listed as second quality, but I couldn't find any flaws in it.
I wasn't too worried about wetting out this glass because I was going to use System Three Clear Coat, which has worked fine for the high-thread-count lightweight glass I've been using for the Prospector models and the Caspian Sea kayak. I did try a small bit of the glass on a flat panel, and it appears to work great. The glass itself is very drapable, but not fragile like 8-harness satin weave is supposed to be, probably because of the high thread count. The pattern is also quite nice, and I'll probably leave it show through on the topside for traction. (I ended up using mostly Raka 350 epoxy, which is more viscous that Clear Coat, and this caused some problems with the wet-out.)
I decided to modify the Delta V in other ways. I used 1/4-inch strips instead of the 3/8-inch strips specified for the hull. I hope that this works out OK. I thought that the S-glass I used would have enough strength for this thickness of strips. I also decided to use uni-directional carbon fiber tape in a number of areas, as J. R. Sweet had some at very attractive prices. This would, however, probably make the boat not conform to the NS14 rules.
My plan was to first strip and glass the hull, using bead-and-cove strips. I would build a hull cradle to support it while working on the interior of the hull. Then I would use left-over bead-and-cove strips to make several bulkheads, including the transom, which would be glued to the hull to further support it.
Next I would strip the deck and glass its interior. I would attach the mast partner and the spinnaker pole supports to the underside of the deck. I would then build the remaining bulkheads and the daggarboard trunk and mount them all in the hull. Then I would glue the deck to the hull and bulkheads. The chainplates could now be attached to the bulkheads.
The last parts to be stripped would be the cockpit floor and sides. The cockpit sides would again only be glassed on the interior (non-visible side). The supports for most of the hardware would be attached to the cockpit floor and sides and then they could be glued to the deck and bulkheads.
Finally, the exterior of the deck and cockpit sides could be glassed. This allows a single 60-inch piece of glass to be used for both the deck and the cockpit sides and also used to strengthen the hull-deck join.
Making the daggarboard, rudder, rudder cassette, and tiller is largely independent of making the hull. Even fitting the daggarboard into the trunk can be done before or after it is made part of the hull. (Actually before is somewhat preferable, as it would be easier to fiddle around with this task without having to move the entire hull for access.) Preparing the spars and rigging is similarly independent of other tasks, at least until final assembly of everything.
This account of my building effort is not quite in the order that it actually occured. Instead this account is more in a logical order. In some cases I have noted where the account diverges from a chronological order.
Determining exactly what hardware (blocks, cleats, etc.) to use took quite a bit of thought. I didn't like some of the choices made by the designer, and thus needed to determine what I wanted instead. This thinking process continued throughout the building of the hull and deck and was only finalized just before I joined the hull and deck, when I needed the first bits of hardware.
I put together a list of all the hardware I used. Most of the hardware was from Harken or Ronstan. The mast, boom, and associated hardware were from Dwyer Aluminum Mast Company. After thinking of using a stiffer mast, I decided to retain the specified mast. I decided to rig the boat with high-tech rope instead of wire, using deadeyes from Precourt. I mostly did this as I could thus easily adjust the length of standing rigging. I also decided not to use a windward sheeting car. This was partly to save money but also because I could then use smaller track, which I think fits the boat better. I decided to run the halyards internal to the mast, mostly to make the boat look nicer. I modified the main sheet tackle, the boom vang, and the cunningham, using ideas from Harken and Ronstan. Finally, I decided to add a trapeze to the boat.
One important issue was how to fasten the hardware to the boat. Much of the hardware is subject to fairly heavy loading and thus needs to be well secured.
I mostly used ideas from the Swift Solo, using leftover bits of bulkhead material for backing plates. In many places I used Stainless steel machine screws anchored with stainless steel flanged weld nuts (available from McMaster-Carr). The weld nuts were placed on the underside of the backing material with the sleeve of the nut projecting up into the backing material. Epoxy was used to glue the nut to the backing material. A second backing piece was used to ensure that the weld nut does not separate from the backing. While the epoxy is curing a machine screw coated in release agent (carnauba wax) is threaded on the nut so that the threads of the nut are not fouled with epoxy. This ends up with a low-weight, high-strength fastening mechanism.
For the mainsheet traveller track I decided to use flanged serrated nuts instead, as there are has 20 screws, and weld nuts would end up being overkill. The jibsheet track attachment is accessible, so I just used regular nuts and washers.
Some items, notably the stempiece, are anchored
in sold wood. Instead of using wood screws, I took an idea from
Gougeon Brothers, and drilled
oversize holes to hold two nuts, one near the bottom of the hole and one
at the top. The holes are filled with thickened epoxy, which securely
holds the nuts.
The only problem with this attachment method is that
you have to be careful when screwing into it. If you misthread the
bottom nut and force the screw into it, you can end up "stripping" the
epoxy. The bottom nut then just spins and you can neither remove nor
insert the screw. Fortunately, it is possible to drill out the hole and
remove everything and then redo the attachment.
There was quite a bit of preparation before the real work of building the Delta V could begin.
The first task was to cut out the forms. There are ten forms, on a 16-inch
spacing. I used 1/2-inch plywood for all the forms, as this makes
for lightweight forms.
Everything is much bigger for a sailboat, even a dinghy, than for a canoe or kayak. I used three 4 foot by 8 foot pieces of plywood for the forms, gluing the forms I printed to the plywood and cutting them out with a jigsaw. I then sanded the forms down to the line using a stationary belt sander.
The next step was to cut the strips.
I bought a bunch of 2-by-4 Western Red Cedar boards (14 14-footers and 6
10-footers) from a local lumberyard.
(There is quite a difference in price between 2-by-4's and 2-by-6's for some
reason.)
I wanted non-flat sawn boards, but couldn't get enough.
I then cut the boards into strips, cutting the flat-sawn and
non-flat-sawn differently to end up with the proper grain orientation.
Some of the boards had their grain shift down the length of
the board, so some of the strips have shifting grain. I
placed these strips near the top of the hull to achieve a
hopefully-interesting visual effect.
Unfortunately there is a lot of waste in cutting 2-by-4's into strips.
I could only get 16 strips out of a 2-by-4, so I thought that I would be a
couple dozen strips short. It turns out that I wasn't short, however, as I
used the strips quite efficiently.
I ended up with a bunch of thin strips, ranging from 3/16-inch down to under
1/8-inch, most of which ended up as scrap.
I decided to lay out the strips for the cockpit, hull, and deck so that I could set up a nice-looking design, and so that I could determine which strips need to have beads and coves put on them. The hull side will be mostly dark, with white pine accent strips. The cockpit will be mostly tan, with some variation. The deck will have an arrowhead-like layout, with 1/4-inch white pine accents.
The next step was to cut beads and coves on the strips for the hull.
I set up my router in the router table and ran through all the strips
for the hull twice, using a climb cut to get cleaner cuts and using
multiple finger boards to hold the strips solid and tight so that the beads
and coves wouldn't wander and so that the strips wouldn't launch through
the router.
I decided to make a laminated inner stem so I measured the stem diagram
and made a stem form. After some adjustment I cut the stem form and
put in holes for the bending clamps. I then cut several 1/4-inch by
5/4-inch strips and used a bunch of thin strips from the regular
cutting. I steamed these strips and bent them on the form, in two
batches. After they dried, I glued them. I used epoxy, and also put
three layers of the 9-ounce S-glass in as well, as I wanted a
very strong stem. This made quite a mess, but I sanded it reasonably clean
using my belt sander.
As specified in the Delta V building instructions,
I made a ladder-style strongback.
I used 3/4-inch oak plywood cut into 6-inch
strips and screwed together to make two 6-inch by 1.5-inch planks 9.5 feet long.
I cut supports for these planks to sit on sawhorses, leveled
everything out, and threaded the eight large forms onto these planks.
I then added on a narrower section with its own support and put the
front two forms on this narrower section.
Note that the front form has a slot for the stem form to fit into. I cut a slot in the stem form and fitted it to the front form. I faired the laminated stem using the belt sander. I then clamped the laminated stem to the stem form and faired it in place.
The next stage was to strip the hull.
The first strips of the hull were quite easy to place as they have no
sharp curves.
I put a white pine accent strip as the fourth strip on the hull.
The only issue is that the first strip was a bit short.
I latter extended this strip at the stern with a bit of a matching strip.
I wanted to have accent strips that were parallel to the waterline, at
least for the front half of the boat.
When I got close to the waterline, I measured the front forms to see
how much distance was left to the waterline. I then marked and
trimmed several strips with a chisel and then sanded them smooth.
For the first strips I tried cutting off the cove side and putting in a new
cove by using a rasp in a grove, as suggested by Bram Dalley, but this took
too much time. For the next strips I cut off the bead side and put on a
new bead with a radiusing tool from Lee Valley. This was much faster, and
the chiselling and sanding did not damage the cove edges much, if at all.
Two narrowed strips were put on the boat with a full-size strip in
between, then the distance to the waterline was measured yet again, and a
third strip cut down and put on. Then the two accent strips and a
separator strip were attached.
After the accent strips were added, a few more strips were added until
the sides of the hull were finished. These strips interlock in unusual
fashions, and cutting out a slot for the next strip is rather tricky. I
ended up having to patch a few gaps in this area, but fortunately I could
use the end of the appropriate strip so the result doesn't look too bad.
Between adding these strips, I cut off the protruding ends of the previous
strips so the bow finally began to take close to its final shape.
At this point, I put a strip down the centerline of the boat, tucking it
into the two previous strips.
I then filled in the two open areas on the bottom of the boat, alternating
strips parallel to the centerline with strips parallel to the gunwales.
The front of these strips had to be trimmed appropriately and then either a cove
or a bead had to be put on the cut bit of the strip.
I used web clamps to keep the strips in place and to make sure that the
hull didn't float off the forms.
The first few of these strips were easy, as they ran off the stern of the
boat so their length was not critical. However, the remaining strips had
to be trimmed at both ends, which, as usual, was much harder.
The final few strips were, as usual, hard to place, because they had to be
bent when being installed. I cut the bottom off the cove on the last two
strips, but it still was a struggle to force them in.
The next step was to smooth the outside of the hull.
I started the smoothing process with a plane and spokeshave, to get the
major bumps off.
Then I continued with my random orbital sander. I attached the dust output
of the sander to my shop vac, which made the process almost entirely free
of dust.
I faired the bottom of the hull with a sanding board, and finally sanded
out the sanding marks with a final pass of the random orbital sander.
After the exterior of the hull was smoothed, I put a layer of 9-oz S-glass
on it. First I put on a seal coat, and when this was starting to set, I
filled in the cracks with a mixture of epoxy, wood flour, and quartz
micro-spheres.
Glassing required two lengths of 50" fabric, which I overlapped about
5" along the midline. I then put System 3 ClearCoat epoxy on the glass.
This did not go as well as I had planned, as the glass is very
closely-woven and the temperature was low, which made the epoxy thicker. I
was left with some air pockets along the threads of the glass, particularly
where there were two layers of glass, and some cloudy sections, where the
small air bubbles did not out-gas.
However, the end result is not too bad.
I added three fill coats to bury the glass and provide sufficient depth for
fairing the exterior.
After the epoxy hardened, I faired the result using the random orbital
sander and the fairing board with wet-sanding paper glued on it.
The next task was to build a cradle for the hull. This was used as a
place to put the hull while the inside of the hull is being finished and
while the deck is being prepared.
The first part of the process was to cover the cradle area with plastic and
cut out a piece of indoor/outdoor carpet to size.
Then six layers of 6-ounce glass with some carbon fiber tape for
stiffening was laid out and glued together. This was done in two steps so
that the glass could be wet out.
Next wood stiffeners were cut out, placed on the cradle glass, and glued
on.
Epoxy fillets were then added, using a mixture of epoxy and glass fibers.
Then two layers of epoxy mixed with graphite dust were added.
The final step was to glue the carpet to the cradle using contact cement.
Much later, after the hull was finished, I put wheels on the cradle, making it into a simple dolly for moving the hull around.
After a hiatus to finish my Caspian Sea kayak
and to do other things, I popped the hull off the forms, put it on the
cradle, and sanded the inside of the hull.
I used a paint scraper to scrape off the remaining glue.
For sanding, I mostly used my random-orbital sander, but also had to do a
bit of hand sanding at the bow.
I then glassed the interior of the hull.
I first put a seal coat on the interior and filled gaps with a
mixture of epoxy and, and quartz micro-spheres. I didn't use any wood
flour for color as none of it can be seen in the finished boat.
When this was non-tacky, I placed 9-ounce S-glass transversely across the
hull, overlapping the sections about two inches.
I used only a single coat of epoxy to glue this glass to the hull, as it
is all inside the boat.
Instead of using a keel plank, as specified in the plans, I instead used
two strips of carbon fiber tape as stiffeners, running them all the way
from the stern to the bow. I laid the two strips right next to each other
except where the daggarboard opening will be and by the bow stem.
As mentioned above, this use of carbon fiber will probably make the boat
not conform to the NS14 rules. However, the carbon fiber did a great
job of stiffening here and elsewhere.
I next attached the transom to the hull, to provide strength for the hull
as the cradle does not provide as much support as the forms.
(See below for how I built the transom.)
For glue, I used epoxy and plastic mini-fibers with wood flour for color,
because the transom join will be visible.
I put a 1/4-inch radius fillet on the interior join, to further strengthen
the transom-hull join.
The next major part of the construction was to strip the deck.
I flipped the strongback and forms over to use the other side of the forms to strip the deck. As the deck is nearly flat, there was no need to use bead-and-cove strips and even no need to bevel the strips. I selected several contrasting strips for the outside edge of the deck, the centerline, and the edge where the deck meets the cockpit.
I started by attaching the second strip to the forms using hot-melt glue.
(The first strip extends beyond the forms, and thus is not as easy to
attach to the forms.)
I then placed a pair of center-line strips and then the outside strips.
Next came a pair of white pine center-line strips, then three strips along the deck
edge, followed by a third pair of strips down the center.
I used fiber tape to force the strips together and spring clamps to force
them into alignment.
The next strips I placed were the ones along the edge of the cockpit.
These strips follow the cockpit sides for a while and then angle in towards
the center line. I cut each strip into two pieces and glued them together
at this angle.
I put five strips along this edge, matched up with the five strips along
the outside edge of the deck.
I purposely cut the strips so that the joints did not line up.
I stripped the rest of the deck parallel to the angled strips, to give an
arrowhead design. I cut some white pine strips in half, to give a
pinstripe look. These pine strips alternated with some
visually-interesting strips and some background strips, in a fairly regular
pattern, with some modifications near the front of the cockpit.
I worked both forward and back, letting the glue set up between strips.
After a while I did two strips at a time, cutting, sanding, gluing, and
taping them in one operation.
All these strips were quite easy to do as I used the wheel on my belt
sander to trim them to the correct length,
after cutting the strips roughly to length using a mitre saw.
For most strips the curve where they met the edge strips was so slight that
the end could be just sanded straight.
The toughest strips were the last two near the bow, as these had to be
sanded to fit the curve of the edge strips.
However the sander did an excellent job of trimming down to the correct curve.
The last part of the deck to be stripped was the narrow rear deck.
I finished up at the stern with some background strips, to give a
closure to the stern.
I decided to work on the deck in a non-standard fashion. I wanted to leave the top of the deck unfinished until the very end so that I could glass the top of the deck and the cockpit all together. This required taking the deck off the forms and working on it before any glassing is done, and had to be done carefully to avoid splitting the deck.
I popped the deck off the forms and flipped it over. The deck popped of
very easily, with no damage. I placed the deck upside down on the deck
forms, which provide some support, but not complete support. I then
carefully smoothed the underside of the deck with my random orbital
sander.
I then (after a delay to build the bulkheads
and put them in the hull) put on a seal coat and filled in the cracks
and levelled off the hollows with a mixture of epoxy and microballoons.
I then glassed the underside of the deck with some 60-inch fiberglass.
I added carbon fiber tape for stiffening down the centerline
and along the middle of each side, extending all the way from the bow to
the stern.
I then built the mast partner, adding two extra layers of strips and
fiberglass where the mast will penetrate the deck extension.
I also added carbon fiber tape along the edge of the deck where it will not
be supported.
Note that this section is not in chronological order with respect to the previous sections. Several of the bulkheads were built during the process of building the hull or deck, and the transom was attached to the hull just after it was glassed, before the deck was built. The bulkheads and small pieces were finished and some were attached before the underside of the deck was glassed.
A major difference between a canoe and the Delta V is that the Delta V has seven transverse bulkheads. The order of stripping between the various parts of the Delta V is a bit tricky if one wants to make the best use of the cedar strips. It is convenient to strip the bulkheads early, but the bulkheads are also a good use for left-over ends of strips, particularly as the bulkheads should be stripped with vertical strips.
I decided to strip the two bulkheads that have external faces, the transom and the bulkhead that forms the front of the cockpit, with horizontal strips to look better. As these bulkheads do have external faces I also decided to use select strips and to strip these two bulkheads early on. (As it turned out, I did these two bulkheads very early on, during the stripping of the hull, as the weather was too cold to work on the hull for quite a while, but I could do the bulkheads inside.) I also stripped these two bulkheads as one unit, from which the two bulkheads were later cut.
As the bulkheads are flat and I wasn't using staples, I had to cut
some straight lengths of plywood to act as clamps. I then cut strips to the
correct length (59 inches) and arranged them in a nice pattern. Next, I edge-glued
these strips (in batches of about eight), clamping them between the plywood clamps.
I smoothed the strips using a scraper, a plane, a spokeshave, and
a sanding pad.
I then put a seal coat of epoxy on one side.
When the seal coat had set up a bit I made a very dry epoxy mixture with
microballoons and a bit of sawdust for color and used it to smooth
out any voids and low spots.
Then I put a layer of 9-ounce S-glass on. (Having some 60-inch S-glass
was very helpful here.)
On the exterior side I also put on fill coats, but I left the interior
without fill coats, to save weight.
Finally I glued printed outlines on the board, and cut the transom and the
bulkhead that forms the front of the cockpit out of this panel.
This bulkhead has access ports in it in the plans, but I decided not to add them.
As the deck and cockpit are stripped with regular strips,
as soon as I finished the hull I took the left-over bead-and-cove strips
and scraps to make a panel for two more bulkheads. (Building these
bulkheads even earlier would also have allowed them to be used to keep the hull
in its correct shape while the deck and cockpit were stripped.)
I used a spare 4-foot by 8-foot piece of particle board as a flat base
for this panel and the plywood clamps to keep the panel flat against this base.
I scraped most of the glue off one side of the panel and then
smoothed it using my plane and random orbital sander.
Then I put a seal coat on the panel and glassed it with the 9-ounce
S-glass. I did not put any fill coats on the panel, as it will be an
interior panel.
The process was repeated for the other side of the panel.
To cut out the bulkheads, I glued the bulkhead outlines to the panel with
rubber cement. I then cut out two bulkheads from the panel, and then sanded
them to the line.
As I had a bunch of 10-foot strips reserved for the cockpit sole and sides,
there was no need to delay making the remaining panels until
the cockpit sole and sides were done.
So as soon as the deck was stripped, I started on these panels, working on
them more-or-less in parallel so as to minimize the number of times I had to
prepare epoxy.
First I glued up a panel for both sides of daggarboard trunk and the mast base.
The unit will be attached to the hull and bulkheads.
I used nice-looking strips for top of the daggarboard trunk as it is visible.
I took extra care to make the inside of the trunk very smooth, so that the
daggarboard will slide in nicely.
I then applied glass to this smoothed side and cut it in half.
I cut out cedar blocks for the fore and aft ends of the daggarboard
trunk and mast step. I put glass on the exposed interior sides of these
blocks and glued the panels to the blocks.
I rounded the exposed edges of the unit and
then glassed the exposed exterior sides of the unit, running a single piece of
6-ounce glass all around three sides of the unit and around the front of
the daggarboard trunk part of the unit.
The front of the mast step will be glued to a bulkhead, so it didn't need
to be glassed.
I cut out drain holes for the mast step part of the unit and then sealed
the edges of the holes.
I arranged the last three bulkheads so that they almost fit within a 50-inch
height and glued up a panel that could be glassed to fit the bulkheads. I
purposely made the panel non-rectangular and put the glass on with a bit of
a curve to fit the bulkheads.
I then smoothed the panel with a plane and sander
As all these bulkheads were interior I didn't take too much care in the
smoothing process, resulting in some tear-out with the plane, which was
filled with epoxy filler.
I applied a seal coat to the bulkheads, then a smoothing coat of epoxy
mixed with lightweight filler, and finally I applied glass to both sides
of the panel.
I carefully placed the bulkhead patterns on the panel and cut them out and
sanded to size. I then put all the bulkheads in the boat to see how they
looked. I noticed that the gunwale of the hull had spread just aft of the
bow, so I put some webbing clamps on to try to bend it back a bit.
There are several small pieces that have to be made for the way I put the boat together.
First, I needed two holders for the spinnaker pole, which is 2 inches in
diameter.
I built these holders from strips, making blocks three strips wide, five
strips high, and 9 inches long.
I placed carbon fiber tape between the lowest three layers of strips, for
extra stiffness. To help carry the load from the head of the attachment
machine screws, I embedded oversize washers between the second and third
layer of strips where the screws are placed. I drilled small pilot holes
in the bottom two strips so that I could accurately place these washers.
I needed two blocks for the rudder gudgeons. These blocks are used to hold the rudder off the stern so that it can easily pivot. I took this idea from the Swift Solo. I built the two blocks as one unit, making a block three strips wide, three strips high, and 12 inches long. The blocks don't need to be three strips wide but I did this to allow the screws for the rudder gudgeons to be placed in the middle of a strip instead of at a glue line. To strengthen the block I placed glass between each layer. I also needed attachment blocks to attach the transom bar to the transom. I again built one unit, making a block three strips wide, five strips high, and 12 inches long. This was twice as big as needed for the transom block, but the extra will probably be useful.
When all the blocks were made up and the glue had hardened, I sanded them
on the belt sander.
I finished the spinnaker pole holders by cutting the block into two sections and using the end of the belt sander to sand out a receptacle for the spinnaker pole. This didn't work as well as I had thought, as the radius of the end of the belt sander was too big.
I thus made up a second set of spinnaker pole holders, starting in much the
same manner.
However, this time I used a hole drill to cut out the
recesses for the spinnaker pole.
I first drilled pilot holes using a dowelling jig to get them straight and
then used the hole drill from both sides.
As the hole saw didn't make it all the way through the block I then used my
jig saw to finish off the cuts.
This method worked very well.
I next sanded the recesses a bit bigger than the spinnaker pole.
I then cut the ends of the holders at 60 degrees tangent to where the pole
will be and then sanded them smooth.
I cut the rudder gudgeon blocks and transom bar attachments to size and shape on
my table saw.
I then glassed their exposed surfaces. For the rudder gudgeon blocks I
used some lightweight glass that I had, as I wanted the glass to sit well
around the corners of the blocks.
The stempiece was bigger than the inner stem cross section, so I needed to extend
the stem backwards to serve as backing for the stempiece.
I cut out seven pieces of left-over bulkhead material to roughly fit,
sanded them lightly, and glued them in place.
I then sanded them smooth along the top.
As the lower shrouds are placed at a 25 degree angle, I made blocks to
provide this angle. I took some extra bulkhead material, cut out four
12-inch by 1.5-inch strips, and glued them into two blocks.
I then cut the blocks at a 25 degree angle and then cut them in half to
make four 6-inch long angling blocks.
I also cut out some extra bulkhead material to double the bulkhead where
the chainplates are attached. I shaped this to match the bulkhead on the
outside and had a nice curve on the inside.
Taking another idea from the Swift Solo, I built a transom bar. This bar will be used to attach the upper rudder gudgeon block (and maybe help prevent the skipper from slipping off the back of the boat). The geometry of the transom of the Delta V is different from that of the Swift Solo so instead of the transom bar coming out of the deck, it will be tangent to the deck. This requires a bit of extra work.
I built up the transom bar from seven layers of strips, two strips wide. I wanted the transom bar to cover the entire width of the transom, just under 60 inches, so I built it 60 inches long. As I already had the appropriate curve for the transom bar on the transom form, I used it as a jig. As the forms are only 1/2 inch wide, I edge-glued the bottom pair of strips on a flat piece of plywood. I next sanded both the top and bottom of this pair flat (and also removed all the exterior wood glue, which would have otherwise interfered with the epoxy.)
I then placed this pair of strips on the transom form, after cutting out
two clamping holes, and glued two more pairs of strips to it with thickened
epoxy. As is usual, I used first primed the strips with unthickend
epoxy. I placed a layer of carbon fiber tape between each of these layers,
as extra stiffener. (The Swift Solo uses a carbon fiber wrap for the
transom bar, but I wanted to have the wood show.)
As I had 3-inch carbon fiber tape and the transom bar is only 1.5 inches
wide, I cut the tape in half lengthwise. This was a bit of a pain, as
there is little glass holding the carbon fibers together and the fibers
next to the cut tended to try to escape. I had to collect the escaped
fibers and lay them down individually. Fortunately, only two or three
fibers managed to escape on each side.
I then glued three more pairs of strips to the transom bar, separating
these with fiberglass. This made the transom bar six strips high. The
seventh strip was added later, to make the bar flush with the deck.
I smoothed the outside of the bar, cut it to the correct length, and
clamped it to the transom to check it.
I shortened the transom bar so that I could get it into the correct place
(as the deck and stern-most bulkhead limit access to the transom).
I put a 1/4-inch radius curve on the bottom edges of the transom bar and glassed
its bottom and sides.
Next I measured the transom bar against the transom and
cut off the stern 1/4 inch of the transom bar where it will be inside the
transom, so that the entire transom area will be flush.
(You might notice that the bulkheads are already in place in the
pictures, as I actually attached them before finishing the transom bar.)
I cut two strips for the top of the transom bar to the correct length, and
glued them to the transom bar.
Then I put a 1/4-inch radius curve on the top edges of the transom bar and
glassed its top and sides, where they are visible, wrapping this glass
around the bottom of the transom bar and finally smoothing out the
underside of the transom bar.
I didn't glue the transom bar to the transom yet, as the cockpit sides and
floor still had to be trimmed to fit, and this would be more difficult with
the transom bar in place.
Now that the hull, deck, transom, and bulkheads were made, I was ready to join the hull and deck.
I levelled the boat by raising the aft end of the hull cradle.
I then carefully positioned the bulkheads in
the hull, ensuring that they
were at the correct fore-and-aft position, vertical, and square.
I marked these positions and lightly sanded where the bulkheads go.
I then cut drain holes in all the bulkheads, except for the bulkhead
interrupted by the daggarboard trunk.
This bulkhead was instead cut in half and drain holes were drilled out of
each of the corners that will go against the daggarboard trunk.
I glued the prepared full bulkheads to the hull, using thickened epoxy, and
then added fillets to both sides, finishing off with a layer of glass.
The fillets were made with a mixture of epoxy and glass microballoons.
This mixture turned out so white and ugly that I added some wood flour to
the second batch, even though it will all be hidden inside the boat.
I then shaped the bottom of the
daggarboard trunk unit to match the
hull, and to make it the correct height all along.
I drilled holes in the hull inside where the daggarboard trunk goes,
so that I could later cut out the daggarboard slot.
I then glued the daggarboard trunk unit
to the hull and the bulkhead in front of it.
When the glue on the daggarboard trunk unit had set, I glued the two pieces of the
last bulkhead to the hull and daggarboard.
I then glued the chainplate backers I
had previously made to the bulkhead,
adding some carbon fiber tape where the chainplates will be for extra
reinforcement.
Finally, fillets were added to the daggarboard trunk unit and the last
bulkhead.
I decided to attach the cleat for the main halyard to the bulkhead next
to the mast, so its back will not be accessible after the deck is joined to
the hull, and thus it needed to be taken care of before the deck is joined
to the hull.
I made a backing plate for the cleat.
I then located the right spot for the cleat on the bulkhead and drilled
oversize holes for its screws. I glued the backing plate to the back of
the bulkhead.
When the glue had set I drilled the screw holes through the backing plate.
I then coated two machine screws and the thread of two weld nuts with
carnauba wax (mold release). I next put some thickened epoxy glue on the
threads and in the holes, placed the weld nuts in the holes, threaded the
screws on the nuts, and filled the hole with epoxy glue. I snugged the
screws up to force the weld nuts in close and put some more epoxy glue
around the nuts to hold them in place.
When the epoxy had firmly set I removed the screws.
I sanded the hull
and bulkheads so that the top edge of the hull
was fair
fore-and-aft and tangent to the bulkheads side to side.
I made a cut-out in the visible bulkhead for the mast partner.
I placed the deck on the hull, moving it around
until it fit best.
As the hull had spread a bit, this required moving the deck a bit forward
from its nominal position.
I placed the spinnaker pole
and holders on the deck so that
the end of
the spinnaker pole was correctly positioned and drilled oversize holes
through the deck for the holder screws.
I then made up backing pieces for the spinnaker pole holders.
I placed the backing pieces under the deck and
drilled screw holes through them.
I then glued the backing pieces to the deck, at the same time gluing the
weld nuts on, as for the main halyard cleat.
I sanded the stern hull flush to the transom. (I was going to put a bevel
on the hull, as on the Swift Solo, for better water separation, but this
was too hard to do. I should have cut the bevel before putting the transom
on the hull, using a guide to get it all straight.) I made a backing for
the lower rudder gudgeon block out
of scrap bulkhead material and glued it to the
transom. This backing also serves to double the thickness of the transom
where the drain plug will be attached. I then attached 3/4-inch by
3/4-inch material, cut from the edges of the plank that was used to make
the daggarboard trunk backing, around the opening of the transom, to provide
stiffening for the transom, and an attachment area for the cockpit.
I drilled a hole for the drain plug.
I made this hole slightly oversize and filled the gap with thickened epoxy,
using the drain itself as a form for the actual drain hole.
I also placed the lower rudder gudgeon block
on the transom, and drilled
holes through it and the transom for the screws.
I then glued in weld nuts.
I did not glue the rudder gudgeon block to the transom, as I wanted to be
able to easily cut the cockpit floor flush with the transom.
Just before joining the hull and the deck I sanded the edge of the hull and the tops of the bulkheads and vacuumed all the junk (mostly sanding dust) out of the hull.
Using yet another idea from the Swift Solo,
I made some ``shear clamps'' from fiberglass cloth.
I cut a 4 inch wide strip, saturated it with epoxy, and draped it over a
2 inch diameter form (the spinnaker pole).
When the epoxy had set, I cut the strip in half, thus making some
quarter-round strips of cloth.
These strips were then tacked to the hull, in the bow area, with hot melt
glue projecting up about 1/4 inch higher than the hull.
Epoxy filler was then put in the gap between the strips and the hull before
the deck was glued to the hull.
The strips bend down under compression, but still keep the epoxy filler in
place, resulting in a good bond between the deck and the hull.
I then made up a batch of epoxy glue and applied it to the edges of the
hull and bulkheads.
I also filled in the glass clamps with epoxy filler.
I carefully lowered the deck onto the hull and clamped it down with web clamps.
I then added fillets along the stern part of the hull and the stern bulkheads.
I left the web clamps on until the epoxy glue had fully cured.
The forestay stempiece, the chainplates,
the spinnaker sheet block eyestraps,
the jib sheet travellers,
and the spinnaker tack sheet cleat
all attach to the deck.
Some of this hardware (in particular the forestay stempiece) requires a smooth
surface for correct installation.
As well, the chain plates stick up through the deck and would make later
smoothing of the deck difficult.
Therefore I next smoothed the deck with a plane, my random-orbital sander,
and a fairing board.
(I had hoped to do this later, so that the finished surface of the hull
would not be subject to damage.)
I attached the spinnaker sheet block eyestraps in the usual manner.
However, I first made up a bunch of backing plates,
cutting part of a left-over panel into roughly 2-inch by 2.5-inch rectangles,
so that I had a ready supply for the rest of the hardware.
I then drilled oversize holes into the stern deck and a backing plate.
I put weld nuts into the holes in the backing plate and glued
everything together with thickened epoxy.
Finally, I sealed the edges of the backing plate with thickened epoxy.
I thought that that this would be sufficient, but I had
problems with the weld nuts being popped off when the screws were
reinserted, as the epoxy does not adhere well at all to stainless steel.
I thus added an extra small backing piece under the weld nuts to hold them
in place.
I attached the forestay stempiece in a somewhat different manner.
The screws for the stempiece go into the
lengthened inner stem and thus don't need
backing.
However, to improve the bond I used an idea from
Gougeon Brothers.
This method requires drilling extra-large holes, large enough to fit nuts
into.
Two nuts are then placed on a machine screw and epoxied into these holes.
The nuts are thus very securely glued in and carry most of the load
directly to the machine screw.
I used this system for the four outside mounting holes of the stempiece, but
just embedded the inner two mounting screws directly into epoxy.
I located where the chainplates for the upper shrouds will come
through the hull and cut slots for them.
As there were some unavoidable inaccuracies in this process, the slot for
one chainplate was rather wide - I thus filled in the opening with a bit of
left-over strip material, cut to shape.
I then put these chainplates through the slots and drilled oversize
holes for their attachment machine screws.
I attached the Precourt
deadeyes to the chainplates to ensure that they would clear the deck.
I then glued the angled blocks for the
lower shrouds to the bulkhead,
located and cut out the slots for them, placed them and drilled holes for
their screws.
I attached the chainplates to the bulkhead with machine screws and nuts,
with washers under the head of the machine screws.
These screws will be inaccessible, so to keep them from loosening I epoxied
them to the bulkhead and chainplates as well as epoxying in the screw holes.
The last part of the boat to be stripped was the cockpit.
I had prepared and set aside 10-foot strips
for the cockpit.
I glued up panels for both sides of the cockpit and the floor of the
cockpit just like I did for the bulkheads.
The cockpit sides will be slightly curved but in the direction of the
strips, so I made up both the floor and the sides as flat panels.
When I had the cockpit floor glued up I smoothed and glassed both its top
and bottom.
I did not completely fill in the weave on the top, adding only one fill
coat, to leave some texture on the cockpit floor.
I did not put any fill coats on the underside of the cockpit floor.
However, I did glue four strips of carbon fiber tape under the cockpit
floor for extra stiffening.
Adding the carbon fiber made an incredible difference to the cockpit floor,
changing it from quite springy to very stiff.
When put in place, the cockpit floor has very little give, even when
walking on it.
I measured the floor of the cockpit,
transferred these measurements to the cockpit floor panel,
and cut it to size.
I also cut out a hole in the cockpit floor for the
daggarboard trunk.
I made the cockpit floor panel about 1/2 inch wider on each side than the
cockpit floor, except where the bulkheads are. This extra width will
provide for better attachment between the cockpit sides and the cockpit
floor.
I glued up the cockpit sides.
Next I rough-trimmed the cockpit sides,
as I had left-over fiberglass (from the cockpit floor) that just barely fit
the trimmed size of the cockpit sides.
I then smoothed the non-visible surface of the cockpit sides and glassed
them.
Next I did the final trimming of the cockpit sides.
Then I smoothed the visible surface of the cockpit sides.
These surfaces will be glassed later along with the top of the deck.
Most of the hardware, including the halyard and vang cleats, mainsheet traveller track and control line deflectors, and some hiking strap attachments, is attached to the cockpit floor. Some hardware, including the traveller control line cleats and some hiking strap attachments, is attached to the cockpit sides.
The first piece of hardware I attached to the cockpit floor was the
mainsheet traveller track.
I measured the width of the cockpit floor where the traveller is installed
and cut the traveller to the appropriate length.
I then drilled holes through the traveller and the cockpit floor.
Next I made up a long backing plate and placed it on the underside of the cockpit floor.
Then I drilled the oversize mounting holes through the backing plate,
securing the backing plate to the cockpit floor with some of the mounting screws.
I glued the backing plate to the cockpit floor with thickened epoxy.
I kept the mounting holes open with screws coated with mold release, which
also served to keep the backing plate in place until the epoxy glue set.
I used flange nuts for the main traveller screws,
gluing them to the underside of the backing plate at the same time as I
glued the backing plate to the cockpit floor.
I had problems with these nuts separating from the backing plate as well,
so I added extra backing pieces to hold them in place. These backing
pieces had recesses drilled in them to hold the flange nuts.
I attached the rest of the cockpit floor hardware,
the halyard and vang cleats and the hiking strap attachments,
in the same manner as for the
spinnaker pole holders
backing plates.
I used the pre-made backing plates,
drilling holes through the cockpit floor and the backing plates
and gluing the backing plates to the cockpit floor
with the mounting screws and weld nuts holding everything together,
Extra backing pieces were glued over the weld nuts to ensure that they did
not move.
To make more gluing surface on the bulkheads for the
cockpit floor I made
some angled strips from left-over bulkhead material.
I then glued these strips flush to the tops of the bulkheads and to the
bulkhead at the front of the cockpit.
I then glued the cockpit floor to the bulkheads.
I then glued one side of the cockpit to the
bulkheads.
(I was going to put the transom bar in before this, but I got the order
wrong.)
This required quite a bit of fine tuning to get the cockpit side in
correctly.
I used several braces and clamps to hold the cockpit side in place while
the glue set up.
When the glue had completely cured, I cut out a hole for
the transom bar in
the cockpit side.
Then I glued the transom bar attachment blocks to the inside of the
transom.
Next I glued the transom in place and left it for the glue to cure.
Finally, I glued the other side of the cockpit to the hull.
After a long delay, I finished off the hull.
The first step of the finishing was to add reinforcement to the part of the
deck that goes over the cockpit.
For each side I trimmed four strips to length.
I cut some carbon fiber tape in half and then to the same size as the
strips.
I glued the strips together with the carbon fiber tape between and
then glued the strips to the underside of the deck.
I then cleaned up the exposed edge of the reinforcement.
I then sanded the deck (actually re-sanded the deck as I had
been sanding it as I went along).
I also trimmed the outside and inside edges of the deck using a 1/4-inch
radius plane.
I also trimmed the mast partner to size and cleaned and trimmed its edges.
To keep epoxy out of the 26 screw holes in the deck and cockpit sides, I filled them
with carnauba wax, using masking tape with a small hole cut out to keep the wax away
from the surrounding deck.
The next step was to glass the deck and cockpit sides.
I glassed these together to get a nice join between the deck and cockpit
sides, but it is not possible to use one piece of glass for this, as the
forward cockpit sides are under the deck.
I first put a seat coat of epoxy on the deck and cockpit sides.
I filled in a few imperfections at this time as well.
Then, on a very hot day I cut some glass to fit the deck and most of the cockpit
sides. I let the glass hang down about 3 inches over the hull, with a line of
masking tape to provide a good edge.
Because of part of the cockpit sides are underneath the deck, the front part of the
cockpit sides cannot be glassed in this operation.
I then glassed the deck and cockpit sides in the early afternoon.
I later cut the hull edge of the glass at the top of the masking tape and removed the
excess. I'm not putting
any fill coats on the deck and cockpit for traction purposes.
Unfortunately, the sun heated up my workplace in the afternoon and I had some
outgassing problems, due to the seal coat not being airtight.
I fixed up a number of these, but a few remain, that I will have to live with.
The next day I cut out glass patches for the front of the cockpit sides, and the
underside of the deck reinforcements. I then glassed this last bit.
I cleaned up the edge of this patch, the edges of the mast partner and the deck
reinforcement, and the edge of the glass that wrapped onto the hull with a scraping
blade and my random-orbital sander.
So that there is no way for water to get into the rudder gudgeon blocks, I drilled out the mounting screw holes in them to 1/4 inch, filled them with epoxy, and then redrilled holes of the correct size. The lower rudder gudgeon block already had mounting holes and nuts, so there was not much to do for it. However, the upper block still needed mounting holes and nuts. I decided to use a method similar to the one I used to attach the stempiece.
I mounted the nuts for the upper block screws in the block itself,
so I drilled out recesses for them.
Then I carefully leveled the boat,
attached the lower block to the boat with the rudder gudgeon,
thrust a 5/16-inch rod into the lower gudgeon,
and marked the placement for the upper block, being careful to ensure
that the rod was vertical.
I then drilled out holes for the upper block mounting screws in the
transom bar, as the mounting screws will
stick into the bar somewhat.
Next I drilled these holes out to 1/4 inch.
I then glued the upper block to the transom bar on the marks,
using the rod as a guide to ensure that the upper block didn't move.
I liberally used carnauba wax on the upper block screws and gudgeon to
ensure that they can be removed later.
Last, I glued the lower block onto the hull in a similar fashion, again
using the rod to make sure that everything lined up correctly.
I cut out the daggarboard slot using a long (16-inch) drill.
I drilled out near the corners of the slot, and, after turning the hull
over, cut between the holes with a jig-saw.
I then used files and sandpaper to clean up the cut-out.
I then sealed the edges of the cutout and filled the slight voids
between the daggarboard trunk and the
hull using epoxy.
I finally sanded this epoxy smooth.
After a very long delay (two years), I finally got back to working on the Delta V. The first task was to build the daggarboard, rudder, rudder cassette, and tiller.
I decided to build the foils from foam and carbon fiber, as is currently done for the Swift Solo. I generally followed the construction methods for the Swift Solo. I bought a supply of carbon fiber, peel ply, absorbent fabric, and plastic sheeting. I bought foam cores from Greg Ryan (NYC skiffs), using the same sizes as for the Swift Solo. Instead of using hybrid cloth, I decided to use carbon cloth and some fiberglass. Some of the carbon cloth I bought from US Composites is heavy (11 oz) so I also modified the layups somewhat.
I thought a long time how to ensure that the clamping boards were straight, which is an essential part of the process. I thought about buying aluminum or steel square rods. In the end I realized that the square rods that are part of Tule car racks are just about ideal, the only potential problem is that they might not be the exactly correct length. In any case, I had four such rods, so I decided to use them. As these rods are very stiff I could then just use some particle board that I already had instead of buying plywood.
I cut stands to go on top of saw horses. The stands are short so the
clamping boards can be placed on the saw horses, and narrow so that the
Tule rods can extend beyond them. As well, the top piece is only screwed on to
the stand so that it can be removed to get out of the way of the rods.
As the rudder is not
as wide as the daggarboard, I cut a little riser for the rudder clamping
boards. I then cut clamping boards for both the rudder and the
daggarboard. The picture shows the clamping boards next to the Tule
rods (with their plastic end-caps removed.)
I decided to make the rudder first, as it is smaller, and, hopefully
easier. I glued the two pieces of the rudder foam core together and also glued
the waste parts together, as they are used to put pressure on the
layup. I then glued the foam core to the stands and put the entire
assembly on a pair of sawhorses. I put little stops on the sawhorses
to prevent the assembly from moving and also used a bit of plastic
sheeting to prevent anything important from sticking to the sawhorses.
I cut the fabric for the rudder.
I used 6-oz fiberglass cut somewhat short, 11-oz carbon fiber,
6-oz fiberglass cut a bit short, and 11-oz carbon fiber.
I marked the mid-point of each by pulling a thread, which was useful to
help place the fabric.
The remaining pieces of the layup are peel ply, absorbent fabric, and
plastic sheeting.
I applied the fiberglass and carbon fiber to the foam core in the usual
manner, and then added the peel ply, absorbent fabric, and
plastic sheeting.
I then placed the foam blanks and clamping boards on the layup and
clamped everything together using the Tule rods.
After the epoxy had hardened, I took off the clamping boards and the
plastic sheeting.
I then pulled off the peel ply and absorbent cloth.
Vice grips are an essential tool for
this job as they allowed me to securely grab the peel ply and absorbent
cloth and pull in different directions.
I noticed that I had let the clamping foam drop a bit too low on end,
resulting in a non fair leading edge near the top of rudder. I decided
to sand and fair this problem later.
I put together the foam core for the daggarboard in the same manner.
There were a couple of special issues in cutting the fabric for the
daggarboard as I had some 49-inch fabric and the daggarboard needed
25-inch wide pieces. To better utilize my expensive carbon fiber
fabric, I cut it asymmetrically. This worked out OK, but I should have
been even more aggressive, as the daggarboard really needs 25.5-inch wide fabric.
I used full-length 11-oz carbon fiber, 6-oz carbon fiber cut 16 inches
short, 9-oz S-glass, 6-oz carbon fiber cut 18 inches short, and 11-oz carbon fiber.
I laid up the fabric in the usual manner, except that the end of the
foam core tore off the stand on the fourth layer. This required some
fancy handling of the assembly, but I managed to prop up the end with a
piece of scrap and proceed, losing only about 1 inch. I then clamped
everything together, waited until the epoxy hardened, and then removed the
peel ply.
The peel ply leaves a textured surface.
I faired this surface on both the rudder and the daggarboard with some
epoxy blackened with graphite powder and thickened with silica
thickener and quartz micro-spheres.
I then sanded both of them smooth using a fairing board.
It was a bit odd adding the filler and then sanding almost all of it
off, but, aside from being very messy, this worked out well.
I also used this filler to fill in some minor problems in the
daggarboard resulting from it breaking off the stand.
I dug out the foam at the ends of the daggarboard and rudder to a depth
of about 1 inch, and filled the cavity with a lightweight mixture of
epoxy, micro-spheres, and graphic powder.
I finished the tops of the rudder and daggarboard by fairing this filler
surface flat and epoxying a cosmetic layer of carbon fiber to the top.
I finished the tips by sanding a fair surface and putting a seal coat of
epoxy on the tips.
Finally, I made a last sanding pass and
put on three coats of
clear System 3 WR-LPU.
There is a good document on making the rudder cassette for the Swift Solo. It starts out with a foam core that will later be destroyed, which I didn't have so I decided to used the somewhat older method of using the rudder as the blank for the rudder cassette. To make sure that the rudder cassette can be removed from the rudder, I decided to use two layers of plastic sheeting inside the layup. As my span between the rudder gudgeons is larger (11 5/16 inch) than for the Swift Solo, I had to slightly modify some of the dimensions. With the larger span, wider carbon fiber tape is called for, which meant that I could easily use the 3-inch carbon fiber tape that I had.
I glued the rudder back on the stands.
Then I used some double-sided tape on the trailing edge of the rudder
(actually carpet tape for its thickness, to round off the the trailing
edge a bit) to start the first layer of plastic sheeting, which I made
very wide, over 20 inches. After I
wrapped this layer, I secured it back to itself with some double-sided
tape. (This time some no-thickness tape.)
The next layer of plastic sheeting was only tacked to the first in a
very small spot under the layup area, but I made a larger connection
outside of the layup area.
Then I wrapped 14-inch wide absorbent fabric around, followed by the
peel ply.
Next came a layer of 6-oz carbon fiber, 50-inches long, making in
effect two layers of carbon fiber.
The middle of the layup was two 50-inch layers of 9-oz S-glass.
The outside of the layup was 50 inches of 11-oz carbon fiber.
All the fabric was 12 inches wide.
Then came peel ply, absorbent fabric, and finally plastic sheeting.
Doing the layup was a bit of a pain as, even though the absorbent fabric
didn't move, its thickness still made the layup feel insecure until
nearly the very end.
Having the wide plastic sheeting protected the rudder from the
inevitable messes.
The wrapping process but a fair bit of pressure on the leading and
trailing edges of the layup.
To put some pressure on the middle, I again used the waste part of the
foam cores, lightly clamped to the layup.
When the epoxy on the rudder cassette had cured, I removed the clamps, cut
everything off the stands, and removed the outer absorbent cloth and
peel ply.
Because I laid up the rudder cassette to the end of the rudder,
they adhered to each other at this end.
(On reflection, I should have made a collar of plastic sheeting to
prevent this.)
I trimmed off this end about 1/8 inch with a cross-cut saw.
I then pulled the rudder cassette off the end of the rudder.
It came off quite easily.
I made up the pintles of the rudder cassette by wrapping some 3-inch carbon
fiber tape around a 5/16-inch rod (which will later form the pintle
pin).
I thought for a while how to get the wrap started nicely, discarding
several plans involving double-sided tape.
In the end I just waxed the rod with carnauba wax and wrapped some
masking tape inside-out around the rod. This made a nice sticky surface
to catch the ends of the carbon fiber. I wet out two 12-inch sections
of the carbon fiber, wrapped most of them around the rod, and hung some
clamps on to keep everything tight.
I also made up a length of roughly 1/4-inch square carbon fiber and
epoxy, to be used as a spacer between the rudder cassette and the pintles.
When the epoxy had cured, I pulled the pintles off the rod (this was very easy). I then hard-cured the pintles and spacer by putting them in a warm oven. I then cut off the trailing end, sanded them smooth, and used a file to remove the masking tape from the inside. I trimmed the spacer to the length of rudder cassette and sanded it.
Because I made the rudder cassette on the rudder, it didn't have a foam
core so I couldn't glue it back on the stands to put the pintle and
reinforcements on it.
Instead I drilled holes in the stands, threaded two rods between them,
and mounted the rudder cassette on the rods. I had to be careful to make
the top holes very near the top of the stands, as I wanted to rest the
pintle rod on the top of the stands when I was attaching the pintle.
Before attaching the pintles, I taped off the middle 5 3/4 inches of the
rudder cassette so that I could easily remove everything there.
I glued the spacer to the rudder cassette, but only outside of the tape.
I also put the pintles back on the pintle rod and
glued them to the spacer, being very careful to make everything lined up
and centered. I used spacers above the stands to hold the pintle rod in
the correct position. Having a rod through the rudder cassette made it
easy to line up the pintle rod straight and even.
When this epoxy had set up, I faired the space from the pintles to the
rudder cassette with more epoxy.
When this epoxy had hardened I sanded it smooth.
The next step was to wrap the top and bottom of the cassette with carbon
fiber tape. I cut two 12-foot pieces of 3-inch tape and rolled them up.
I added more masking tape, because the previous sanding step had messed
it up somewhat.
I tacked the first carbon tape with a bit of 5-minute epoxy. Then I
unrolled the tape around the cassette, epoxying it on.
I found that a good method was to start out with some epoxy in place,
unroll the tape on one side of the cassette making sure that it lined up
correctly. Then I pulled the tape tight without moving it laterally.
Next I put some epoxy on the tape, smoothed and tightened it with a squeegee,
and finished off by putting on more epoxy making the section ready for
the next wrap. The epoxy removed by the squeegee made up part of this
additional epoxy. I covered the tape with a layer of peel ply,
smoothing it and pulling it somewhat tight.
I made up 6-ounce batches of epoxy, which was just enough for the tape on one side of the cassette. The first 4 ounces I thickened with a but of silica. The last two ounces thickened on their own, and, as a bonus, I thus ended up with clear epoxy for the outside of the wrap. The slightly-tacky epoxy left over from the first tape was used to start the second tape.
At this time I fabricated the rudder pintle rod.
I took the 3-foot long, 5/16-inch stainless steel rod I bought from
McMaster-Carr and cut a 13.5-inch
section off it.
I smoothed one end of the rod on my belt sander and then drilled a
1/8-inch hole near the other end.
After smoothing this hole, I spliced a loop of 1/8-inch V12 rope through
it.
Two washers will be used on the pintle rod,
one on each side of the rudder cassette so that it does not wear against
the gudgeons.
To make washers that fit snugly and were not too big, I slightly
enlarged the holes on three 1/4-inch washers.
When the epoxy had hardened I removed the outside peel ply and cleaned up the
epoxy over the masking tape.
I then cut the
cassette to the exact dimensions needed (11 1/4 inch), allowing for
space for two stainless steel washers
on the pintle rod, and test hung it on the rudder gudgeons.
I then rough-sanded the entire cassette.
The next, and most aggravating step in making the cassette, was to
remove the peel ply and absorbent cloth from the inside. The fact that
my cassette is over 3 inches higher than the Swift Solo cassette made
the job much harder, as it was very difficult to work on the middle of
the cassette.
After the peel ply was removed, I cut out two 2-1/2 inch holes.
I also made the tiller over a foam core.
I ordered carbon fiber sleeves from
Soller Composites.
The sleeves easily conformed to the tapered tiller core.
I wet out the core and applied a carbon fiber sleeve.
Next I applied a 12-inch reinforcement sleeve at the large end of the tiller.
The next layer was some of my unidirectional carbon tape. I applied one
3-inch tape the entire length of the tiller and a second tape on the
large end. The final layer was another sleeve. I hung the tiller
assembly vertically, hanging a spring clamp on the bottom to provide
some tension on the fabric.
Working with the carbon sleeves was very easy. They easily formed into larger-diameter sleeves, which I could easily fit over the tiller form and other fabric, even when wet out. For each layer, I applied an initial coat of epoxy. Then I put the layer on, added more epoxy, and smoothed everything out with my gloved hands. After I hung the assembly, I applied more epoxy and smoothed it out again. When the epoxy had cured tack-free, I added one filler coat. When this coat hardened, I lightly sanded the tiller. I then hollowed out the small end of the tiller, where the tiller extension will attached, and filled it with the lightweight mixture of epoxy, micro-spheres, and graphite powder.
The tiller is attached to the rudder cassette towards its bottom.
I made a template of the inside of the cassette and rough-cut the tiller
end to match this template with a jig saw.
I then used a sanding drum on a rotary tool to sand the tiller end to
closely match the outside of the cassette and provide the correct tilt
to the tiller. I measured the correct tilt by
putting the cassette on the boat and figuring out how much tilt was
needed to have the tiller clear the cockpit sides.
When the tiller was sanded correctly, I epoxied it to the rudder
cassette and sanded everything.
When the glue had hardened, I sanded the affected areas.
I then drilled through the tiller in-line with the holes for the rudder pin.
I thought for a long time how to fit the
daggarboard into the
daggarboard trunk.
Methods that have been used for the
Swift Solo are
using wooden blocks fit to the daggarboard,
using carpet (between blocks and the daggarboard,
and using SparTite.
The problem with wooden blocks is that they may not fit exactly,
producing point loads, which can cause failure.
Carpet alleviates this problem, but does hold water, and can hold sand,
which would score the rudder.
SparTite is recommended, but I didn't have any on hand.
In the end I decided to use epoxy mixed with graphite powder and a
bit of quartz micro-spheres to fabricate the gasket between the
daggarboard and the trunk.
I decided not to form the daggarboard fitting block inside the
daggarboard trunk, both because it would have been very hard to do and
because I was worried that something would go wrong and the daggarboard
would get stuck.
I made a form just slightly larger than the daggarboard trunk from some
left over wood. The bottom of the form was also wood, with a
cutout the size of the daggarboard.
I tried a number of ways to make the blocks.
First I waxed the interior of the form and the daggarboard with carnauba wax.
I then added petroleum jelly to the daggarboard for extra release power.
I then fit the daggarboard into the form at the appropriate level,
making sure to have everything level left-to-right, and tilted
appropriately fore and aft. I filled the small gap between
the daggarboard and the bottom of the form with putty.
I then made up some epoxy mixed with graphite power and some (not a lot)
of quartz micro-spheres.
I poured this mixture into the form and let it cure.
When the block had cured, I removed the form and slid the block off the
daggarboard.
This made a decent form, but this form did adhere to the board, and did
slightly damage the board. I think that the problem was that the form rubbed
the release agent off the board. Fortunately, the board was easy to
repair, just needing a bit of resurfacing in a couple of spots.
On my second try I used thick plastic (painters) wrap.
This try ended up very easy to remove, but the plastic wrap separated
from the board, and the block thus did not conform to the board well.
On the third try I used thin plastic (food) wrap. This worked quite
well.
After the good blocks had hardened completely, I sanded them to fit in the
trunk, putting a slight curve on the lower block to conform with the hull.
I attached the blocks to the trunk with thickened epoxy.
First I did the upper block, attaching it at the level of the cockpit
floor.
When the epoxy for the upper block had cured, I pushed the daggarboard
through.
I had to do a bit of sanding to get the correct fit.
Then I attached the lower block flush with the hull, using the same
mixture of epoxy, quartz micro-spheres, and graphite powder as the block itself.
When this epoxy had hardened, I faired the hull around the lower block.
The gap between the rudder and the rudder cassette was much smaller than the gap between the daggarboard and the trunk. It thus only made sense to fill the gap in place. However, this meant that it would be harder to recover from mistakes.
One problem with fitting the rudder into the cassette is holding the cassette vertically while supporting the rudder at the correct position. To hold the cassette vertically I attached the rudder gudgeons to a board and then attached the rudder to the board using the rudder pintle pin. The board could then be clamped vertically, holding the cassette in a vertical position.
I first filled the top gap between the rudder and the cassette.
I mounted the cassette on its board upside down.
I put thin plastic wrap and masking tape around the top of the rudder
and carefully placed it in the cassette, upside down.
I used shims to center the rudder in the cassette and then
filled the lower edge between the rudder and the cassette
with masking tape.
Finally I poured epoxy into the gap, trying to make about a 3-inch-high filler.
Unfortunately, I had a tiny hole at the bottom of the gap, which caused quite
a bit of the epoxy to run out. However, some of the epoxy remained and
I think I have sufficient for the top gap.
When the epoxy had cured I removed the rudder from the cassette and
cleaned up.
I next did the lower gap, making sure not to have any holes.
In any case the lower gap was easier, both because the upper filler helped to
center the rudder and there was more room to anchor the masking tape
that I used to fill the lower edge. As well, I used some putty to fill
the ends, where it is hard to get the masking tape to conform correctly.
When this epoxy had cured, I removed the rudder and cleaned everything up.
TODO
Now that all the messy work with the cassette was done, I did a final
sanding and applied clear
System 3 WR-LPU.
I bought the mast and boom directly from Dwyer Aluminum Mast Company. I bought the mast step and masthead block; spreaders and spreader attachments, tangs for the standing rigging and trapeze, the sliding boom gooseneck and boom outhaul cap, and two bails from them as well.
I decided to run lines through the mast, boom, and spinnaker pole, so I had to attach quite a bit of hardware to the mast, boom, and spinnaker pole. The three halyards run through the mast, so there are five exit blocks for them, two at the mast base for the jib and spinnaker halyards, one near the mast base for the main halyard, and two up the mast for the jib and spinnaker halyards. (The other end of the main halyard goes through the masthead block.) The spinnaker tack line runs through the spinnaker pole and needs an exit block at the front. The outhaul runs through the boom and needs two exit blocks. On the other hand, I decided to use slugs that fit in the sail track for the boom vang and cunningham, eliminating the need for several eye straps or bails.
For most of the exit blocks I used Ronstan 20711 or 20711A blocks. These blocks are small, which is very important when placing a block inside a dinghy mast. Many of the attachments were standard, but some were a bit tricky. To ensure that I didn't mess up the mast or boom, I made a trial run of some of the attachments with some of the left-over mast.
The most complicated attachment was at the mast base, where the jib and
spinnaker halyard exit.
This area needed special work
as the halyards come out of the mast where the sail track is, but the
blocks are attached inside the mast. I should have had Dwyer put a
"sail feed" cutout there, but I didn't think of it in time. I thus had
to cut out the sail track to make room to both get at the appropriate
part of the mast, and to let the halyards exit the mast. I also had to
ensure that there was sufficient room to insert the slugs for the
cunningham and boom vang. As well, I wanted the halyards to come out as
low as possible, so I had to remove a bit of the mast step.
On my first practice run,
I used a hacksaw to cut out most of the mast track and finished off with
a rotary cutting tool.
To cut out the spaces for the blocks, I started with a drill and then
used a rotary cutting tool, finishing off the corners with a file.
I wasn't happy with this practice run, particularly with the smoothness
of the sail feed cutout, so I tried another practice run using my belt
sander to grind away the sail feed. This turned out much better, so I
decided to use this method on the mast.
The first exit block that I attached was the for spinnaker tack line, in
the spinnaker pole. (This was the easiest one, so I did it first.)
I laid out the cutout for the block, drilled some holes with a drill,
rough cut the cutout with a rotary tool, and finished up with a file.
As this block was close to the end of the pole, I fastened it with
machine screws and lock nuts.
I decided to not cut out the sail track for the outhaul exit block.
This meant that I had to install the block on the inside of the boom and
also make its cutout from the inside.
This was a bit difficult, but a preliminary attempt on the scrap
material showed that it was doable. I drilled into the boom from the
top, protecting the sail track by enclosing the drill in a metal sleeve.
I used my rotary cutting tool to enlarge the cutout, working both from
above and from below. When I had the cutout appropriately sized and
smoothed, I drilled the fastening holes with the drill press. As the
block is at the end of the boom, I used machine screws and lock nuts to
fasten it to the boom.
The rest of the boom hardware,
the main sheet bail,
the boom vang bail,
the outhaul eye strap,
the outhaul exit block,
and the outhaul cleat,
were all standard.
I used mostly pop rivets to attach them to the boom.
The main halyard is attached to the halyard cleat on the cockpit bulkhead. This means that it will exit the mast toward the bow, which means that the exit block should be angled forward. Fortunately, there is room between the mast partner and the deck so that the main halyard can be pulled directly vertically.
The jib and spinnaker halyards come out of the mast to the cleats slightly out of line with both the exit blocks and the cleats. I had hoped to angle the exit blocks, but there was no way to install them angled. I could have, and should have, angled the cleats, but I forgot to do so. I'll have to see how this arrangement works in practice as the angles are not large. I have an idea for how to install some deflector sheaves in a very small deck organizer.
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