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by Channing Boswell (Danceswithmullet) -  Bokeelia, Florida - USA

...In Six Weeks

Well after a hectic build and getting the boat to the seaworthy state before the start of the Everglades Challenge, there have been a surprising number of questions about the design of this ugly little boat named Finger Mullet. After thinking about how to make the Everglades Challenge a little more comfortable and a little less painful, Finger Mullet was what I came up with to replace the old Bluejay that I sailed in three previous challenges. My goal was to make a boat with a full enclosure, steerable from inside and unsinkable. I didn't have any plans, just spent a lot of time thinking things through. I turned my thoughts into a 16-inch model carved from foam and from there scaled the lines up onto some cheap ply for a pattern to trace onto sheets of foam.

Why choose this manner of building? Basically, I have no attention span - if you blow up a rubber balloon and release it without tying a knot you get a basic idea of the course my train of thought follows - it meanders all over. This was meant to be a simple build because, in spite of somehow completing major home and boat projects successfully over the years, I still can't measure worth a poop, at least not to the level of making a decent wood boat. Foam is forgiving, easy to shape, and if you mess up slap a little monkey glue on another piece, stick'em together and it is as good as new. Also, Okume ply is hard to come by in my neck of the woods. I sourced the expanded polystyrene (XPS) foam from a supplier that uses it to make faux stonework for homes. Now don't go to Home Depot and think the Styrofoam there is suitable for boatbuilding. Foam is measured in pounds per square foot, the main hull of Finger Mullet is 3lb density foam, and when you try to squeeze it you quickly realize it is nothing like the foam of a Big Gulp cup. Read Surfer Steve's website if you are thinking about building in foam. He provides lots of info and has confidence in foam for boatbuilding. Most of today's surfboards are made from XPS, and surfboards have a hard life.

Now to make sure this stuff would hold up I started out making test panels of foam and glass then destroying them to see what I wanted for a layup schedule. There is really no way for the home builder to test with cyclical loads, so I just put on the leather gloves and made like those monkeys on the old AMAACO commercial with the transmission and hammers. Well, I didn't actually use a hammer, I just pulled, twisted, banged, threw, jumped on, and peeled. This was actually kind of enjoyable and most satisfying at the end of the day. The cussing was optional but lent itself well to the situation. In the end this will actually boost your confidence that this is tough stuff.

The most indestructible way that I found to layup is to sand the foam pretty smooth - no fuzz - layup one side, allow to cure, then using a soldering iron "drill" holes from the clean side down to the glass on the cured side. The iron will melt the foam quickly but not the resin and glass. Once you have your holes, fill with only slightly thickened or plain epoxy and let it cure. Some holes will have to be done twice because the foam absorbs some epoxy. They can still be wet when you put on the top laminate and when it cures both top and bottom laminates will be bonded together making the piece nearly indestructible. I did this on the deck at two-inch intervals and it feels like walking on pavement in bare feet. I did it on other parts of the boat as well, just not as frequently because it wouldn't have the same loads. If you make a test piece you will realize you cannot delaminate the glass past the first epoxy "pillar", this will contain any damage within that zone. The drawback is this is very time-consuming, giving your brain time to calculate the dollars being literally poured down the holes.

Now, back to the actual start of the build - remember I told you about my train of thought. I took two sheets of Luan and sliced them lengthwise at two feet, well actually Home Depot did the slicing. I took these in the house and sat on the floor with my model and pair of calipers and went to work. The model was to scale at 16-inches for a 16-foot boat, so I took measurements at different points on the centerline and transferred them to the two sheets laid end to end on the floor. I only wanted to do one half at this time. Once the points were transferred, I took a string and laid it on the points adding curvature with the string between the points. This was then traced with a sharpie, cut with a jigsaw, and sanded. This is where the next two pieces are laid end to end, and the first pieces are laid on top and traced to the bottom ones, making a symmetrical pattern I could transfer to the foam. I also used the pattern to determine where the mast and centerboard should go, but to be honest that was mostly by eyeball on my part.

Now to get back to the foam! The foam can be ordered in any thickness. I went for 1-inch on the sheets because I thought that would be a good core thickness and with my mathematical skills I can usually handle adding with one's. The foam shop has a CNC hotwire that can cut all kinds of fancy things and if I was smarter I would have had them do some fancy cuts. Being me I went with the flat sheets. The foam was available uncut at 16-foot lengths but cost more than buying a block and having them cut the sheets, but the limit was eight feet with their machine. No problem, gorilla glue bonds foam as if it were one sheet and still sands and allows the hotwire to cut through like one piece. After the pieces were butt-glued and dried, the pattern went on top of the foam, was traced with a sharpie then cut with a jigsaw. The sides were simple 24-inch butt-glued panels, glued to the bottom panel, and a 2-foot square of half-inch marine ply made the transom. Drywall screws can be used to hold the foam in place until the glue cures.

Day two and it already kind of looks like a boat. I didn't realize the level of heartache to go at this point. I had 3-inch 45 degree foam gussets made and they went in the bottom of the hull. This created a better angle for glassing, but also allowed a lot of foam to be removed from the chine to soften the lines. Time to glass the interior. This is where the depression set in on the ability of the foam and glass to soak up the liquid gold "epoxy". My calculations were obviously way off on the amount of treasure it will take to finish this thing and we are only on day three. Really, the foam needs a good seal coat before any glass. The problem is if it is still tacky when laying in the glass it makes life miserable. This was a learning experience. It worked best sealing in the evening then glassing in the morning before it set to the point it would need to be sanded. When the inside had two layers of six ounce glass coating, in went the bulkheads, both half inch marine ply and a one-inch 45 degree gusset one inch from the top for the deck to set on.

I should mention I had two very good friends Dan and Neil helping me with this and it was their egging on that helped me get the ball rolling. While the interior work was going on Dan shaped the "log" as we called it before it was glued to the hull. Dan used to make foam surfboards so his hotwire and expertise came in handy on this build. Now the log is where the boat is supposed to ride, making a narrow underbody that is easily driven, while keeping the spray under the boat. The log was made from a 12"x12"x16' solid piece of 3lb foam. The tricky part with the log was cutting the hole for the centerboard trunk to match with the hole already cut in the main hull. Basically, I climbed on the table, Neil and Dan lowered the boat over me upside down, they placed the log on top, and I traced through the centerboard trunk onto the log. I had a flashlight expecting darkness, but light passed through the foam making the tracing easy. Oxygen was the only concern and with a pea sized brain I could probably last in there for days.

Once the trace was done we put the log down right-side up and drilled a hole in the center of the traced-trunk. We disconnected the hotwire from its bow, fed it through the hole then hooked it back up. The hotwire cuts in any direction so we just kept it level and traced the trunk outline and it made a beautiful cut that dropped the foam cut-out right out of the bottom. The deck went on next with bottom already glassed and the hole-drilling for the deck begun. The inside of the boat was totally glassed at this point with the exception of tabbing the deck where it met the hull. This made the hull a solid form and it could be set in any position to make glassing the outside easier without deforming the hull. I had made the centerboard trunk separate out of Luan, which I thought would be okay since it was coated both inside and out with two layers of six-ounce glass. The trunk was inserted then the entire hull glassed.

Once the hull was glassed, I cut the forward hatch and the cockpit openings for access to tab the deck and centerboard trunk to the hull. This is where the biggest misfortune happened - while pouring thickened epoxy around the centerboard trunk unbeknownst to me it was also flowing INTO the centerboard trunk. I was not happy cutting all that liquid gold out of the trunk and we will leave it at that!

Now for the trickiest part of the whole build, the pilothouse! The multiple angles were way beyond my third grade geometry skill level. Luckily, I had started out using a sheet of cheap foam from Home Depot for a pattern or I would have cried for the crimes against 3lb foam, I almost cried anyway. It took an entire 4-foot by 8-foot sheet to make a two square-foot enclosure, and the shop looked like a blizzard of shaved foam. This was also the closest I came to throwing things - I kind of wished I still had a few test pieces to "test".

Okay, so that's the hull, now for all the extras inherent to a trimaran. At this point I kind of wished I stuck with a monohull. The pieces were sourced after surfing endless hours on the web at work (it is okay they didn't mind). The aluminum tubing came from Online Metals, the fiberglass tubing from a radio antenna company, and most of the rest from E-bay. I wanted this boat watertight so any penetrations had to be sealed. The fiberglass tubing ran along the forward bulkhead and was mechanically bolted to it with stainless steel U-bolts and was glassed to the hull, same with the stern. The mast was just aft of the bulkhead in its own fiberglass tube, which I made from using the mast as a mold, connected to the bulkhead at the top and bottom. The whole set-up would probably carry a freestanding mast with no problems. During the Challenge there were no creaks from this structure and since all the loads are transferred to the bulkhead the only unnerving thing I saw was flexing of the aluminum tubing, it really wasn't bad. The tubing was 6061 at 1/8-inch wall thickness so I doubt it would break, but I plan on adding some stays in the future to the bulkhead near the water line.

The Amas, those extra bits you get to make while making a tri. Well, I actually didn't make them, Dan did. These were made of 1.5lb foam to save some weight and some money. Since the amas were not going to be stressed as much as the center hull we figured glassing them like surfboards along with some reinforcing around the fiberglass tubes would be alright. They also got stringers of ¼-inch marine ply with lightening holes. I glassed the first one and Dan, out of embarrassment on my behalf, glassed the second. His was lighter and looked a hell of a lot better than mine, just another kick in the cojones doing this build.

The trampolines - my wife did the research on how to make trampolines and ordered the supplies from Sailrite. This was "her" project and when they were done they looked like they had come from a canvas shop, although I did hear some cussing now and then when the sewing machine kept jamming up. The tramps made the boat twice the size and definitely added a level of safety, not to mention comfort.

The rig - I had two rigs that were gifts from friends whose hulls had gone to the great fiberglass heaven in the sky - aka landfill. I chickened out and went for the smaller of the two, it came from an FJ. The jib was an E-bay special with no pedigree of the vessel it was for. The combo worked but I never really felt overpowered, even in some pretty strong wind, and it left me wanting for more in the light stuff. The stay system needs a revamp also but will probably wait until I add the bigger rig.

Overall I am happy with the boat. It took the challenge out of the Challenge because I was warm and dry and comfortable during the race, although she is no speed demon. I look forward to improving the boat and using the techniques I learned on other projects in the future, and hopefully she'll look a bit prettier once I have the time to finish her off, amazing what a little paint will do.

Danceswithmullet (Channing Boswell).

 

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