wather proofing wood with polyurethane

Fentress

Songster
7 Years
Mar 22, 2012
588
91
168
Chesapeake, Va.
I built a new coop this year, 10 by 16 on skids, no floor, that I move with the pickup. To protect the wood I painted the exterior with an oil based polyurethane. I know nothing about sealing wood, until just recently when I had a shed delivered and starting looking at the different types of treatments I could use on it. In retrospect, there are water based sealers that are probably less toxic, than the poly. Does anyone think that I have a potential problem health problem with the chickens. The vapors are long gone, at this point it would be a concern regarding flakes coming off the coop and the chickens eating it.

Thanks,

Mark
 
Modern finishes are safe once cured. Normally, this takes less than 24 hours. Unless the finish flakes off the wood, the chickens won't be peeling the finish. And it's true, they eat worse things than flakes of modern paint.

Chris
 
HI,

As a former woodworker I never recommend a polyurethane finish for exterior surfaces. It just doesn't hold up under the adverse weather that mother nature dishes out. It'll be fine for now but it will start peeling and cracking under the hot sun. Nothing you can do about it now except let it do it's thing. Once most of it has peeled you can the sand and refinish with an exterior based product like Sikens, Thompsons, or Flood UV. I like the latter as it is easy to put on and is good for 5 years before re-coating is required. Sikens is the best of the three but is $$$, Thompsons is good but I don't like their exterior with UV.

Not criticizing, just putting my knowledge out there.

J
 
HI,

As a former woodworker I never recommend a polyurethane finish for exterior surfaces. It just doesn't hold up under the adverse weather that mother nature dishes out. It'll be fine for now but it will start peeling and cracking under the hot sun. Nothing you can do about it now except let it do it's thing. Once most of it has peeled you can the sand and refinish with an exterior based product like Sikens, Thompsons, or Flood UV. I like the latter as it is easy to put on and is good for 5 years before re-coating is required. Sikens is the best of the three but is $$$, Thompsons is good but I don't like their exterior with UV.

Not criticizing, just putting my knowledge out there.

J

+1

Polyurethane brings out nice wood color but it is not good at all for exterior wood. It will shrink and flake off within a short time. After if flakes and you sand off the rest then you can use one of the products that "J" mentioned or just a good exterior primer paint mix.
 
Uh oh, I just got through varnishing some plywood with 450 varnish on the recommendation of a couple of rockier clerks. It is a water based polyurethane. Wait, no, it is a polyacrylic... Hope that is better!
 
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Waiting for it to flake and then sand the rest like is being suggested doesn't sound so good to me. First you have poly flakes everwhere, then you have wood getting more weathered by the day, and then you have to strip the rest of the finish and refinish a lot of weathered wood. Maybe you should have used something else but now that it's there, I'd try to maintain it. You have some time. Find a paint store you can trust and ask questions. Google something like "paint over exterior polyurethane". While the finish is still in decent shape you should be able to sand lightly (not take it off) and repaint with something that will weather better. You might have to prime first but maybe not. It should be OK.
 
About the only thing I have seen last outdoors, that gets hard like poly/varnish is a product called spar varnish. It is used allot on wooden boats, but upkeep is time consuming and continuous.

Not sure on how paint/primer would adhere to the poly, might have to sand it with 80 grit to roughen it up first. When I got things in the shop that where poly I stripped them all the way to bare wood and started over, but those projects weren't the size of a chicken coop either.

J
 

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