The Logical Philosopher

Saturday, January 29, 2011

Kayak Build, Part 3

With the hull and deck tacked, I now had to fiberglass and epoxy the inside seams. This was a 16 hour day, with about 12 hours of breaks spread around. My goal was to get the interior epoxied and fiberglassed in one shot, which meant I had to put several layers of thin epoxy on without letting it fully cure inbetween. Although it made for a long day it did reduce the amount of sanding I had to do between coats because the new layer could still bond with the old layer as it hadn't 100% cured yet.

Step 1:

Little J and I prepped the seams with tape on one side, and he removed all the copper stitches from all the joints. We also pulled out the temporary bulkheads and left the one permanent one in place.
Wood Duck 10 Build

After that he set to work mixing, mixing, mixing up epoxy with some wood flour. To make it easier to spread I dumped it all into a plastic bag and piped the joints full.I dont' have much pictures of it because between mixing epoxy, trying to spread it on the fiberglass and keeping an 8 year old occupied I was too busy.
Wood Duck 10 Build

Here's the pro-tips I learned the hard way:

  • Mix up the thickened epoxy and pipe it in using a large ziplock bag with a small 1/4" cut off the bottom. It turned out it only took about 20 minutes to pipe the whole kayak, and then I filleted the joints smooth.
  • I would "pre-epoxy" the permanent bulkhead in so the wood was all sealed up nicely. It was difficult getting the unthickened epoxy on the vertical surface without it streaking down because I put too much on, and then when I worked it thinner it went cloudy on me.
  • Epoxy is a bitch: Easy to do, but hard to do well and still have it look nice when you're done. I floated in on too fast so it turned cloudy and I had to push as much out as possible so I could do several thinner coats instead of a lower number of thicker (and cloudy) coats.
  • I swear there is a "good" and "bad" side to 3" wide fiberglass tape. Some of the edges stood up on some of the parts, and didn't on others. This made for a ridge on some of the 3" fiberglass that I needed to sand down once the epoxy set.

    Step 2:

    With the fillets almost set we peeled off the tape and rolled out some 3" fiberglass on the seams. The tape made for nice and clean fillet lines, so when we put un-thickened epoxy over the 3" tape it made for a nice.

    Step 3:
    The seams were almost set (a few hours later) so Little J and I spread out the fiberglass cloth in the cockpit area. I taped the top 2" where I was going to cut the cloth after it started to set, but if I was to do it again I would have run the cloth over the edges and trimmed it right at the joins after it started to set. This would have made for a nicer finish.
    Wood Duck 10 Build

    Step 4: Epoxy, coat #2 over the full hull interior.
    Step 5: Epoxy, coat #3 over the full hull interior.

    Wood Duck 10 Build

    There were a few Coke breaks in between all the steps, as well as some hockey on the TV!

    Finally, we attached the hull to the deck temporarily so the epoxy would setup with the boat in the right shape:

    Wood Duck 10 Build

    Next up: Coamings, Magnetic Hatches and Recessed Deck Fittings!