Foils Epoxy Coated

Coated the foils with one coat of MAS Flag epoxy resin. I did one side at a time with the foils horizontal. This eliminated runs and allowed for a fairly thick coat of epoxy. A quick sanding and maybe one more thinner coat if needed and the foils are ready for varnish. The rope handle holes are already drilled in the rudder. The dagger board still needs to be drilled. The holes got filled with leftover epoxy and will be re-drilled for the rope. This seals the cedar core preventing any chance of water intrusion. I drilled the rudder before fiberglassing and the drill bit tore out some of the very soft cedar. The clear epoxy has made the tear out all but invisible, nevertheless I think it's much safer to drill after glassing since the glass should prevent any tear out. We will see when the dagger board is drilled.
A couple of tear out gouges I had in the rudder, from inept planing, disappeared almost completely under the epoxy and I have to look real hard to locate them so am real happy about that.


Total time to date: 73hrs

Finally making some shavings

The foils are planed to shape. This went better than expected but I had a couple of problems with the plane tearing out bits of the soft cedar. Maybe my plane is not sharp enough but it's as sharp as I can get it. The clear epoxy will hide the nicks, I think. A bit of sanding to finish off and the foils are ready for glassing.

Daggerboard ready for glass


Rudder ready for glass


Dropped it on the trailing edge #$%@#$!!!


Scarfed in a tiny piece of cedar to fix. I'm sure this wont be the last ding repair.


I decided to vacuum bag the glass onto the foils. This is not necessary at all but I have all the equipment from when I used to vacuum bag composite model airplane wings and the process is pretty fun. One big advantage is that the vacuum forces the glass around the tip contours of the foils and you don't have to do hardly any sanding before the final epoxy flow coats. I did the rudder first and found out that cedar will absorb a lot of epoxy under vacuum. While the layup turned out nice and tight, the glass is a bit dry. This will still work just fine but it's not perfect. I coated the centerboard with epoxy and let it kick before vacuum bagging the glass and the resin ratio was good.


Rudder remover from bag. Just need to trim the edges with a sharp box cutter, sand the remaining ridge and it's ready for the final epoxy coats. No sanding of epoxy lumps and drips and runs.


The glass is formed tightly around the edges of the foil.


Total time to date 70hrs.

Foil Shaping

Finally some progress on the Goat! After the plywood setback I decided to work on the foils and will probably also build the mast before getting back to the hull. In this way I'll have most of the various bits ready to go once the hull is complete.
The dagger board and rudder are made by first ripping cedar and hardwood boards into staves. Then gluing the staves into blanks. The blanks are then thicknessed to 22mm. And then they are planed to a hydrofoil shape. Since my planing skills are at rank beginner level I decided that the foils were not a good first project. I want to finish the foils clear and therefore need the wooden blanks to be shaped as perfectly as possible since I will not be able to use filler to fair out any imperfections after glassing. I would love to have them CNC routed to shape but did not want to invest in the considerable shop time for a one off project. So I came up with a jig which I call the SMC router. SMC for Simon's Manual Control. The jig is made from 3/4inch MDF and it allowed me to mill the blanks to a very precise thickness. I then used it to cut most of the hydrofoil shape, finishing up with a hand plane. As a bonus I'm going to make an angled carriage for the router and use this same jig for scarfing staves for the birds-mouth mast.

Cedar 2x4s from Lowes ripped and ready to glue.


Rudder blank being glued up. I had a bit of trouble keeping the staves from sliding around while the epoxy was curing so I used the table saw table extension as a flat surface to help clamp the gooey mess into submission. Wax paper kept the table saw from becoming a permanent part of the rudder.


Rudder blank on jig ready for thicknessing.


Router carriage over rudder blank. The carriage is free to slide around but is guided by the T shaped bit on the lower left. As long as a little pressure is applied to keep this T in contact with the fence everything moves smoothly with no binding.

Router carriage.

Router on carriage. The carriage is a bit wider than the router base. This allows the router to be "locked" in position by twisting it slightly so that the flat edge of the router base wedges itself in the carriage. This worked well and sped things up considerably since the alternative would be to clamp or screw the router to the carriage for every pass.


Video of dagger board being thicknessed.

I'm very happy with the resulting blank surface finish and thickness.



Thickness of one end of blank.


And the other end. This level of precision is not too hard to achieve but the jig has to be absolutely straight. Any warp in the base or fence of the jig will be faithfully reproduced in the blank. The first pass with the router showed that I had a .5 to .75 mm warp in the middle of the jig base. I placed the jig base on the table saw assuming that it was perfectly flat. Well it's not and the slight hollow on the table was transferred to the blank. A bit of shimming got that taken care of and the next pass with the router was near perfect.


Once the blank is the correct thickness, width and length a template is used to draw the foil outline on both ends.


Then back on the jig but this time the cutting depth of the router is varied to remove wood up to the pencil line. Then the leftover ridges are planed down with a hand plane. It is pretty easy to get a very straight and uniform profile the full length of the foil since the grooves left by the router make perfect depth gages. Stop planing as soon as the groove disappears and you are at or very near the correct profile.


Trailing edge being routed to shape. I left a lip on the end of the trailing edge to support the thin section while routing the other side. The lip is easily planed off afterwards.


Rudder blank ready for hand planing to final shape. Oh almost forgot, the blank is held down to the jig with sheet rock screws. Two are located where the rope handle holes will be drilled later. The other end of the rudder was left about 1 inch too long to allow for the clamping screws. In this way there will be no sign of the sheet rock screw holes in the finished rudder.


Total time to date 56 hours.

Bad plywood

The learning curve has reared up and smacked me in the head. I know you are supposed to use BS1088 rated Okoume marine ply. So I ordered 6 sheets of the stuff from a very large, local, supposedly reputable distributor. They had a fantastic price on the 6mm at $50 a sheet. I double checked with them that it is BS1088 and they assured me it's the right stuff. I picked it up and it looked fine as far as I knew. Once I got it home I realized that one side was A grade but the other had some footballs here and there. At this point I should have realized that this ply was more BS than 1088. But the footballs were few, the real stuff is $80 a sheet and returning this lot would be a pain. So I decided I could lay out the parts such that any football was on the inside of a buoyancy tank or underside of a seat. I forged on and cut out all of the pieces. Everything went as planned and I did not find any voids in the ply, so far so good. I was always a bit puzzled by the look of the grain but never let that get in the way of cutting out parts and making progress. While staring at the pile of cut parts I decided to do a test on some scraps to see what this stuff will look like once epoxy coated.
Well, this is what Tank thought of it:


Some of the sheets are a red-brown with nasty splotches and others are closer to the golden color I expected but still do not look all that good. Long story short I'm scrapping the whole lot and starting over. The boat would be perfectly sound if built from this stuff and would look great once painted, but it's not acceptable since I'm finishing the interior clear.


After doing much research it appears that the ply I have is a China imitation of BS1088 and like many products made there, buyer beware. The glue is probably made from dog poo. To be fair it is pretty OK stuff, especially for the price. Five ply with no voids, the outer veneers are a bit thin but OK, just don't expect to finish it clear. The search is on for a local or within reasonable driving distance supplier of Joubert brand BS1088 Okoume or equivalent.

Cedar Key small boat meet.

At the rate I'm going the Goat will be built in 2020. There is just too much fun stuff to do on the weekends that gets in the way of building. Last weekend was the West Coast Trailer Sailing Squadron's Cedar Key small boat meet. The only small thing about this affair is the size of the boats. There must have been at least 70 small sailboats, kayaks and UFOs (F for floating). We met a bunch of fascinating people and had a great time. I even passed a tough test when Mike Leneman, who I had just met, set me up by asking which epoxy I had used to do a repair. Fortunately I answered West System Gflex not realizing that the other gentlemen listening to our conversation was Meade Gougeon Of West System fame, whew good answer :-) Anyway more boat building to follow soon but for now some piccies from Cedar Key. Oh, and the Canon is still dead so these are from iPhone and an ancient Olympus. Click on the Cedar Key 2009 link under the pictures if you want to see the whole album.

From Cedar Key 2009

From Cedar Key 2009

I got a water resistant pouch for the iPhone so we took it out on the water. Below is our GPS track from the iPhone superimposed on Google Earth. MotinX, the $3 GPS app I use, generates a .kmz track file which can automatically be displayed in Google Earth. I just email the track to myself or anyone else and its done. No more forgetting to download your trip track from the Garmin. The track starts on the beach at Cedar Key goes to Atsena Otie island and back to Cedar Key. Then I forgot to turn it off so it logged my walk back to the hotel.

From Cedar Key 2009

Planing hull sides to shape

I used a jigsaw with a metal cutting blade to cut the 4 hull sides to within a mm or two of the lofted pencil lines. The instructions say to plane to the line but to not remove the line. Makes sense since once you plane off the line you really have no idea how much material has been removed. The whole process was a lot easier than I expected. I adjusted my plane for a very fine cut and easily removed the high spots and then worked down to the pencil line. This is my first time working with a plane. It's now my new favorite hand tool.
Once the two left sides were planed to size, I used them as templates to mark out the right sides. Then cut and planed to size. A tiny bit of final planing was done with the two sides stacked. This way they are essentially identical in shape, and hopefully very close to the plan.


You can just barely make out the pencil line.


Time spent: 3 hours
Total time to date: 16 hours 30 min

Stern stems laminated

The inside and outside stern stems are laminated at the same time but separated with some poly. The inside stem remains on the form and is shaped before the strips are laid down. The outside stem is installed after the stripping is done and then planed and sanded to shape. That's 12 strips laminated together with epoxy. Dave says it was a messy job but manageable.