Options for water sealing wood

[sms986]

I'm just poking around for some options for waterproofing-or at least water-resisting wood. I'm rebuilding the gunnel panels, engine doghouse, and cabin of my boat next. Everything is above the deck. I'm looking for an effective-cost conservative method of sealing up the plywood panels before upholstering. Based on the cost of resin and stuff for redoing the deck and everything else, I'm not too hip on encapsulating the panels with glass, or even laminating with epoxy or poly resin. If a panel rots years down the line, no big deal I can replace them. I'm using arauco plywood to do all of the above deck work since the cost of fir is now through the roof. Any recommendations? Thanks!

 

[JASinIL2006]

Got this from Woodonglass; credit goes to him.

 

[Chris1956]

I would use some plain spar urethane. That holds up well in direct sunlight, in a marine environment. It will work well under vinyl.

Catalyzed poly resin will also work very well under vinyl. No FG cloth needed.

Not to disparage Woodonglass and others, but I do not understand how linseed oil and polyurethane are compatible. Every urethane label I have read says wood must be clean and dry.

 

[sms986]

I'll do some reading up on these two options. Maybe run a few trials. Thanks guys!

 

[Woodonglass]

I would use some plain spar urethane. That holds up well in direct sunlight, in a marine environment. It will work well under vinyl.

Catalyzed poly resin will also work very well under vinyl. No FG cloth needed.

Not to disparage Woodonglass and others, but I do not understand how linseed oil and polyurethane are compatible. Every urethane label I have read says wood must be clean and dry.

Mix some up and try it! You’ll get your misgivings answered.

 

[Chris1956]

OK Woodonglass, your recipe for varnish/oil/turpentine has a following on the internet. It is meant for interior fine wood working.

They say add more oil for a close to the wood look and add more polyurethane for more protection.

In the marine environment, for the OPs needs, I do not know why he would add any oil, as he is covering it with vinyl.

 

[Woodonglass]

We’ll all I know is this.. I coated a 1’ x 1’ piece of OSB with the formula left it exposed outside to all kinds of severe Oklahoma weather rain snow sleet heat everything and after two years of exposure it still was a solid piece of OSB plywood

 

[Berdink]

We’ll all I know is this.. I coated a 1’ x 1’ piece of OSB with the formula left it exposed outside to all kinds of severe Oklahoma weather rain snow sleet heat everything and after two years of exposure it still was a solid piece of OSB plywood

And OSB just crumbles at the site of water. That says a lot for OTF.

 

[ShoestringMariner]

Wait, I’m dead sure I’ve seen this OTF with Spar Varnish instead of Poly. Are Spar Varnish and Poly similar?

 

[JASinIL2006]

I think the formulation with poly is newer and better.