Wednesday, April 28, 2010

Epoxy, Sand, Clean - Repeat

After the fiberglass cloth is on the boat, the process of building up the level of epoxy begins. It took about 3 coats to get the thickness up out of the cloth in all areas and begin to smooth out. The first couple of applications tend to take on the texture of denim. It then must be sanded smooth before the next coat is applied. Washing the boat between coats was done with a bit of dish detergent and some vinegar in warm water. After that a couple of rinses with wet toweling and a bucket of water to keep it rinsed out.

I decided to put a wood skeg fin down the center of the bottom to provide directional stability. Reading on the Glen-L website there were builders that added them later due to getting stuck in wake troughs and having bad things happen. The alternative is a small metal fin in the center of the boat that is about 8" long and 4-5" deep, but these are prone to damage if a boat is beached or in shallow water. Since a wood skeg fin is also somewhat prone to damage, I read that white oak is a preferred material for it hardness and rot resistance.

I called up my friend Kevin, who is a timber framer and asked if he had a bit of white oak. Since he wanted to see my boat, he offered the board as admission price. We thicknessed planed it and it was more than enough for the job. The skeg is about 5 ft long and tapers from 2" tall at the back to 1/2" at the front. It is held on with 5 - #10 x 2" long screws countersunk and plugged with white oak plugs. I tapered the trailing end to hopefully eliminate any water disturbance that might cause prop cavitation.

The other finesse job needed was squaring up the bottom to transom corner to eliminate potential porpoising. I duct taped a board and clamped it to the transom to provide a dam for the epoxy. A batch of epoxy with microglass fibers was mixed up and squeegeed along the edge. After cure, it was sanded down to match with the bottom and transom surfaces leaving a very crisp corner.
Another coating of epoxy was needed and before the last couple of coats I actually read the bag that the foam rollers came in and they showed cutting rollers in half and then into three crescent shaped sections and using them as a touch off "brush" to smooth and take out surface air bubbles. It worked great and made the epoxy much smoother with fewer valleys, sags, ridges,
or surface bubbles.

After several cycles of sanding, cleaning, and epoxying the boat does not look much different in pictures, but the smoothness and depth of the finish has improved.

I made a cradle for the boat to sit on once it is
flipped over. It can be seen leaning against the wall in the photo. Its all from 2x6 lumber, scribed to somewhat match the contours and will sit level. I drilled holes in the corners to accept some large casters that I bought about 30 years ago at an industrial resale shop. Thought they might come in handy someday. Hope this is that "someday"! On garbage night I found a nice clean carpet remnant that I can "recycle" to cover the cradle to protect the boat bottom that hopefully will get painted soon.

The last photo shows a different view to see the skeg and the finish before I began sanding with 120 grit to flatten and get ready for painting.

After a complete sanding with 120 grit paper, it appeared that I may have sanded down to the fiberglass cloth in three spots. Since I won't have time to begin the painting for at least another week, I cleaned and put another coat of epoxy on the whole boat. Hopefully, the last one. The epoxy needs to fully cure for a week before painting, so it should be ready when I am.

Monday, April 5, 2010


Once the boat looked all nice and shiny with perfect wood grain showing through the epoxy finish, it was time to mess it up...big time. So I fiberglass taped and epoxied the joints. I started with the keel joint and used 6" wide tape.
This tape was taped into place with some blue tape to hold it straight and overlapped the transom about an inch. The boat was already prepped for another coat of epoxy, so the fiberglass tape was epoxied and the whole boat got another coat of epoxy. After watching the Glen-L video on how to epoxy a boat, I followed their best practices of taping all joints before using the fiberglass cloth to cover all surfaces. The chine joints were taped and then the transom to bottom and sides were taped. Foam rollers were used to saturate the tape with epoxy. I found a 3" roller worked the best as quite a bit of rolling pressure is needed.

After trying some different epoxy filler to fair in the tape edges and finding sanding difficult, I went and bought some West Systems 407 fairing filler. Since the bottom will be painted, I got over the need to keep the wood pretty and figured I may as well use the right stuff for the application at hand. This filler is supposed to be mohoghany color, but it reminds me of chocolate milk. I slapped it in the areas needed to smooth out the tape transitions and sqeegeed it into a somewhat smooth surface. After curing, sanding with an orbital sander and 80 grit paper worked well and edges could be feathered and surfaces smoothed quite readily. At some point in this process, my wife came down and said "What the Hell?". I quickly explained "It all gets painted later". So it all looked like hell, but was smoother. I kept with just clear epoxy on the sides so I can keep the natural finish, but unthickened epoxy runs and sags like crazy (after you leave the room - just to be sneaky) so its a bit of work to scrape and sand them out.

Then I fiberglassed the transom as suggested in the video to get some practice and confidence. The cloth was cut and taped in place to overlap the bottom by 1-2" and trimmed to fit over the sides a like amount. Corners were smoothed into shape without cutting. Epoxy was rollered in and it all went smoothly. After cure, the edges were sanded down to feather in.

I then laid out the bottom fiberglass cloth on the bottom and trimmed to fit about an inch inside the chine line. My friend Ted said he kept all the cloth overlaps on the bottom of his boat and it simplified the feathering process, so I did mine the same way. I precut the cloth for the sides by splitting lengthwise some 38" wide cloth and rolled it up on shop vac pipes. My daughter's boyfriend, Brett was here for an Easter weekend visit, and since he has fiberglassed a boat before, he was drafted into service. We mixed epoxy, rolled it on the bottom and smoothed out any wrinkles and bumps. Brett mixed more epoxy batches, I rolled, and it progressed quickly. We then pre-coated a side and rolled out and positioned the cloth to overlap the bottom 2-3" and trimmed the ends as needed. We rolled on some more epoxy and worked it into the cloth and then did the final side. My daughter Katy joined in and we had three rollers going. It took about 1 1/2 hours to complete the job. After curing for a few hours, the fiberglass hanging over the edges was trimmed with a utility knife. It felt good to have this major step behind me. Thanks Brett!