Have you checked your deck fitting for leaks and wet core issues? If not you really should. A wet core will kill the decks on the U20. You should check and reseal your deck hardware regularly to prevent this issue. Alternatively you can follow the steps below and hopefully never need to worry about it ever again.
Last fall I purchased #63 built in 1996. The boat was well maintained but did have some leaking deck hardware. Thankfully most of the deck holes were dry inside, but a few were damp and a couple had some rotten balsa around the bolt holes. Time for a head liner replacement? Thankfully not. There is a method to fix minor balsa rot issues without cutting into anything. This is a method that I used on my old San Juan 21 which also had a balsa core deck.
Fixing the deck takes a few steps, but it will create a permanent fix. If you want to solve the problem forever it’s worth it to treat every hole on the entire deck. This makes for a time consuming job, but your boat will thank you in the long run. So here are the steps:
1. Remove all deck hardware, this mean everything, every cleat, pulley, guide, and track, including the hatch tracks.
2. Get a few medium sized nails and bend the tips to 90 degrees at a variety of lengths. Use these nails to probe all the holes searching for wet balsa and rot. If you find any wet balsa or rot, use the nails to clean out as much of the bad core as you can through the holes. You’ll be surprised how much material you can get out from around the holes. Work each hole until you (hopefully) hit solid core. Even if you don’t find any wet balsa, it’s worth it to use a drill with the nails to rip out some of the balsa core around the holes in preparation for Step 5.
3. If you can get all of the rotten core out but it still seems wet, you may still be ok if you have some time and a dry place to let the boat sit. Several of the holes on #63 were still wet when I took everything apart last fall, so I covered the boat and let it sit in a dry place all winter. This did a good job of drying out most of the core. If you live in a humid climate the core many never dry unless you can get the boat inside.
4. What if you still have water in the core after letting the boat sit for a while? If you have a lot of holes that are still wet you may be out of luck and may need to cut things out to fix it. If it’s just a few holes, there is one other trick you can try. Number 63 had two holes that didn’t dry fully over the winter so I had to use my last option, a micro fan. I built a little fan using the motor and rotor blade from an old micro drone. I made a housing for it out of cardboard, hooked it up to a C battery, and taped it to holes blowing out. The C battery will run that little fan for five days constantly circulating air through the wet holes. After the fan treatment my holes were completely dry and I moved to Step 5.
5. With all of the deck holes clean and dry, I mixed up some West Systems epoxy with low-density filler added and then proceeded to fill up all of the holes. This took and entire day and in retrospect I probably could have been it easier with a syringe to inject the epoxy into the holes. The holes will take quite a bit of epoxy and may need to be ‘burped’ a few times to completely fill them. The epoxy should attach to and seal all of the balsa around the holes, preventing future wetness problems.
6. After the epoxy cures, redrill the holes and reattach the deck hardware using an appropriate marine sealant. If you can avoid it, don’t use silicone. Silicone works for a while but is not a good permeant seal and is almost impossible to remove completely if anything needs to be resealed in the future.
So there you go, you owe it to your boat to inspect the deck hardware to see if anything is leaking. A fix now could save you a major headache down the road. This seems a like a big job, but if you do it right your balsa core will thank you and should never need repairs. Good luck!
