Spar Urethane vs resin... wood

chrisf695

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Hi Guys... just need a little insight on which to use for my upholstery project... I'm Replacing the wood for my interior(panels and bench seat) and would like to seal or protect the wood from the water, humidity, etc. I can tell the original wood was not treated and it lasted over 15 years. So would the spar urethane do the trick for this project? Or do i need to use a thin coat of resin on this? Trying to do this at a low cost and my dad is telling me to use the spar urethane... he said the resin would be kinda over kill... but hey... whatever. Ill ask you guys.

Thanks!
 

jigngrub

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Re: Spar Urethane vs resin... wood

The Spar will be fine for your application and more readily available.

Use 3 coats of the exterior indoor/outdoor grade.
 

chrisf695

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Re: Spar Urethane vs resin... wood

What about the bench seat and sunpad? Would that do the trick too? Thanks for the quick response!
 

chrisf695

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Re: Spar Urethane vs resin... wood

Right on! LOL love this forum!! quick answers!

Thanks!
 

64osby

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Re: Spar Urethane vs resin... wood

On Plywood just make sure the edges get coated / covered really good. Seal the edge each time you coat the flat surface and the edges will have 6 coats and the flats 3.
 

salty87

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Re: Spar Urethane vs resin... wood

agreed for interior purposes. besides you'd need to use epoxy resin which is more expensive. poly resin without chopped strand mat won't stick for very long.
 

rockyrude

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Re: Spar Urethane vs resin... wood

On my dad's old wood boat he used a spar urethane that had a U.V. blocker in it for the sunny areas.
 

Chris1956

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Re: Spar Urethane vs resin... wood

I use poly resin on wood inside and on the bottom of cushions. It works real well, and only takes 1 coat. I would be afraid the moisture would penetrate the spar urethane.
 

jigngrub

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Re: Spar Urethane vs resin... wood

I use poly resin on wood inside and on the bottom of cushions. It works real well, and only takes 1 coat. I would be afraid the moisture would penetrate the spar urethane.

If you didn't use some fiberglass mat or cloth with that poly resin it will flake off eventually.
 

GA_Boater

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Re: Spar Urethane vs resin... wood

Spar varnish was developed to protect spars on sail ships way back when. One of the qualities is flexibility on spars bending in the wind. Seating on seats will most likely flex a bit. Three coats as 64osby described will last a long, long time. Poly without CSM will not last very long. I use the Helmsman jigngrub referred to. My 2 pennies.
 

Chris1956

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Re: Spar Urethane vs resin... wood

Whereas I agree that poly resin w/o cloth will not last on areas that get abraided like floors, I disagree that it will not last on plywood used for seat bases, that get no abrasion. I have used it and it lasts years and years. I consider it to be tougher than any polyurethane or varnish, and more waterproof. I have never seen poly resin flake off. I used it on a pair of wooden waterskis in the 70s and it was much superior to the varnish that was available back then. We skiied a lot back then....
 

Friscoboater

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Re: Spar Urethane vs resin... wood

Actually, if you mix the Poly to kick off very slow it soaks in just fine and will give great protection. Plus if you use a quality resin that is very thin it will soak in perfectly. The problem with most resins is that they are too thick, and kick off to quickly to soak in. Just like anything else, if you do it right, it is fine.

I believe urethane has to be re- applied every few years. I know the rails at our dock do.

I too have never seen it flake off. I have seen it crack due to the fact it was pooled on the surface. A thin coat is the secret.
 

chrisf695

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Re: Spar Urethane vs resin... wood

So... I am completely done with all the coats of the spar urethane, total of 4 coats and edges got double... so 8 there. I lightly sanded after each coat with 180 grit so the next coat would grab on more and I am very confident that it will hold up for many years. I think the whole idea of having to re-coat the surface of the wood like stated above with the spar urethane is that the item was in direct sunlight and sooner or later will break down and will need more coats to be added. The wood that I am coating with the Spar urethane will not be in the sun, but will be covered by the upholstery. Yes there will be moisture...its a boat. But that's what this product is made to do, be resistant to water. So with that... thanks for the recommendation of this product.
 

Friscoboater

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Re: Spar Urethane vs resin... wood

Our dock rails are not in the sun at all, and we have to do them every few years. There is a reason why the factory does not use urethane.

Just my 2 cents.
 
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