Alex_c
Well-known member
I completed my tinboat project just about a year ago, and I have had some issues with the products I used. I stained my decks (exterior grade ply) with some oil based stain and then coated with 4+ coats of spar urethane. The last coat I applied with a non slip additive mixed in. It worked great but unfortunately the UV resistance has been poor. Everywhere that is exposed to the sun, the finish is starting to crack. At first I thought it was the non-slip additive or the stain that made the urethane crack, but if I lift up a seat and expose an area of the deck that is covered from the sun, the finish is in perfect shape. The undersides of the deck are in excellent condition where I can inspect them, as they are not in direct contact with the sun's UV rays.
So this leaves me with a few questions:
- What is a good cost effective alternative to spar urethane? I have looked at Durabak and Kiwigrip, but both are about $150/Gal and I won't need that much for my boat. Will an exterior deck sealer/stain provide the UV protection I need? I don't mind spending a bit of money, as I am already a bit annoyed with having to re-finish the deck after only a year of hard use, but $150 plus painting supplies is going to be a bit much, considering the wood I'll be coating isn't even worth $100. I would like something that goes on thick and that I can build up. Also something that is relatively easy to re-apply down the road when needed.
- I am guessing I will have to extensively sand down the old finish to get rid of all the high spots where the top layer of ply has started to crack. It's not de-laminating, but when it gets wet, the wood will swell under the cracks in the varnish. Should I completely sand all the old finish off, or am I ok to scuff it up enough for the new coat?
- How long will my deck last if I just leave it as is? Might be more cost effective to re-do the deck in a couple years with a more UV resistant finish, as opposed to spending $200+ on refinishing that may or may not extend the life of the wood by that much.
So this leaves me with a few questions:
- What is a good cost effective alternative to spar urethane? I have looked at Durabak and Kiwigrip, but both are about $150/Gal and I won't need that much for my boat. Will an exterior deck sealer/stain provide the UV protection I need? I don't mind spending a bit of money, as I am already a bit annoyed with having to re-finish the deck after only a year of hard use, but $150 plus painting supplies is going to be a bit much, considering the wood I'll be coating isn't even worth $100. I would like something that goes on thick and that I can build up. Also something that is relatively easy to re-apply down the road when needed.
- I am guessing I will have to extensively sand down the old finish to get rid of all the high spots where the top layer of ply has started to crack. It's not de-laminating, but when it gets wet, the wood will swell under the cracks in the varnish. Should I completely sand all the old finish off, or am I ok to scuff it up enough for the new coat?
- How long will my deck last if I just leave it as is? Might be more cost effective to re-do the deck in a couple years with a more UV resistant finish, as opposed to spending $200+ on refinishing that may or may not extend the life of the wood by that much.