clear coat on dory

[bart]

Is it possible to use something more penetrating and therefore more permanent on the inside of a Swampscott dory planked with cedar than varnish? I like the look of the wood but want it to last. Also, what do you all recommend for the little cracks that are to big for sealer but need to be filled to keep the misc. detritus out? I like the idea of leaving them open because water wouldn't get trapped between planks in case of a leak on the outside.

[Wild Wassa]

A marine 2 pack water based clear polyurethane would be an option at about 2 and 1/2 times the cost of a fine marine varnish.

Polyurethane is not an easy material to apply. The poly that I use, BCP's Aquacote, skins very rapidly, in a matter of seconds, at normal temperatures. If it's cool, below 16C you will get about half a minute before it skins and when it shrinks it shows every blemish. One other thing about poly is, when it's time to remove it, you will wish that you had not put it on your boat. The most you will get out of poly before it's advised to sand and repaint it, is 2-3 years, about the same as a fine marine varnish. If your boat is on a trailer and covered you will get a good life out of poly, that is one slight advantage over using varnish.

Stick with varnish because it is so easy to apply and remove. Varnish takes exactly the same degree of maintenance as the poly. I like the poly because I can cut and polish it to a glass like surface.

If you do use a clear poly, dilute it (thin it) to the manufacturer's max advised recommendation, otherwise you might be a bit disappointed with your results. Poly has no self levelling characteristics, unless you use an additive like Floetrol.

Warren.

[ 08-13-2004, 10:14 PM: Message edited by: Wild Wassa ]

[paul oman]

Seal the wood with clear epoxy then topcoat with the varnish. You will get something much better than either one alone and the varnish will protect the epovy from UV damage.

I also know of clear 2 part acyrlic polyurthane clear coat with max UV blockers added that prevent epoxies from yellowing, however, the varnish adds a warmth and depth that the synthetic clearcoats lack.

paul oman
progressive epoxy polymers
www.epoxyproducts.com/marine.html (http://www.epoxyproducts.com/marine.html)

[jimnmad]

I used Deks Olje on the inside of my dory and it seems to be holding up pretty well. Available from Flounder Bay.

[Wild Wassa]

I edited out the Deks section from my posting, thinking that it would complicate the matter. I'm sorry that I did now. Good choice Skipper. I've not run into anything more simple to use than Deks. The only problem that I see with Deks is people don't allow it to cure for long enough ... before using their boats.

Warren.

[ 08-14-2004, 05:19 AM: Message edited by: Wild Wassa ]

[Bruce Hooke]

I too, would lean towards an oil finish (such as Deks) -- it's very traditional in a dory and should be a less work to maintain (of course it is also a lot lower gloss than varnish). But, the prep work for it needs to be just as good as it would be for varnish. Also, the work to maintain it is likely to be small amounts of work on a regular basis as opposed to a big job every once in a long while.

I would hesitate to use epoxy on a traditionally constructed dory. A dory does, to some degree, depend on the planks swelling to seal the laps. Epoxy is not condusive to that process. However, you could probably get away with it if you really wanted to because this would only be on the inside...

If you want a good book on traditional marine finishes I highly recommend Walter J. Simmons' book Finishing. You can get it from the WoodenBoat store. It has a good section on oil finishes.

[bart]

Thanks to you all. I will lean toward the oil finish. Another criterium that I didn't mention was a flat look. I was going to go with linseed and turps until I found out it would darken the wood too much.