# Water based Polyurethane Offgassing



## higherroad (Dec 4, 2012)

I finished a project recently, a desk organizer that is rather large, with Varathane water based polyurethane. I applied 4 coats with 3 or 4 hours between each one. I then put it in the garage to dry for a week, actually 10 days. It's completely dry but it still smells pretty strong. I put it in my office today and when you walk in the room you notice the odor of the poly immediately. I put it back in the garage until I can get the odor to dissipate. My question is, how long does this take until the odor is un-noticeable? Is the odor toxic or a health hazard. I seems like it is. I suspect this may be normal but how do you address this with your own pieces? How long do you wait until you bring a poly finished piece into your living enviroment? It's kind of strange that they finish floors with poly but no one talks about the odor exposure much. Thank you.


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## Steve Neul (Sep 2, 2011)

What was the temperature when you finished it. If the temperature was 50 degrees or lower you probably needed a lot more time between coats. I've never used the Valspar water base but something unusual is going on. Normally the offgassing with water based finishes is trivial. What you can do is put a window fan blowing on it for a day or two. The ventilation should solve the problem. If the odor is that strong it's not healthy to breathe.


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## Fred Hargis (Apr 28, 2012)

Temperature is certainly more critical to a water borne finish than the oils. I suspect that was the issue. Yes, those fumes are to be avoided...they are not healthy. the fan is a good idea, so would a little heat if needed.


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## cabinetman (Jul 5, 2007)

higherroad said:


> I finished a project recently, a desk organizer that is rather large, with Varathane water based polyurethane. I applied 4 coats with 3 or 4 hours between each one.


How did you apply the finish? You may have applied each application too heavy, and it didn't cure (completely). For all subsequent applications, they will delay the previous one from drying out (completely). I added "completely" just for Fred.:laughing:








 







.


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## TomC (Oct 27, 2008)

Maybe I can't smell but I have been using the same brand of water based poly and don't notice any oder even when applying the finish.
Tom


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## Fred Hargis (Apr 28, 2012)

cabinetman said:


> How did you apply the finish? You may have applied each application too heavy, and it didn't cure (completely). For all subsequent applications, they will delay the previous one from drying out (completely). I added "completely" just for Fred.:laughing:
> 
> 
> 
> ...


I think it has to be used with the word "cured"....:laughing::laughing::thumbsup:


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## higherroad (Dec 4, 2012)

I sprayed it with a HVLP. It's now been 5 more days of drying, 15++ total. When I hold my nose close to it I can smell the odor of poly. In an enclosed room I sense a slight smell but it's not overwhelming just slight. What's the longest you've heard of a project to cure to no odor? The irony is that I chose water-based because I was worried about toxic odors!


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## cabinetman (Jul 5, 2007)

higherroad said:


> What's the longest you've heard of a project to cure to no odor?


This project.:yes:









 







.


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## Fred Hargis (Apr 28, 2012)

That would be expected with oil based, but water borne should clear up more quickly. Couple of thoughts: the odor may have permeated something in that room the piece is in, and that's what your smelling. If it is the finish you are smelling, it's not "completely" dry (cured). Back to the fan, have you put a gentle air movement over it? Temp? What about finished interior surfaces that get no exposure to the air? BTW, I don't know who told you floor finishing doesn't smell that long, but they need to talk to my UPS driver. When he redid his floors, the wife accused him of trying to kill her with the odor.


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## Steve Neul (Sep 2, 2011)

The finish is just going to offgas until it cures. Some brands will just take longer to cure than others so you just found the brand not to use. Anyway if the odor level is slight I wouldn't worry about it. Your lucky you didn't use Sherwin Williams nitrocellulose lacquer. I've had projects offgas for a year with that.


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## wooddude (Jun 14, 2011)

thin coats are always the best application,to many things can go wrong with a heavy build such as uneven drying, orange peel,fish eye ect,also the top might fell dry but below the finish is still curing.
99% of the time i use a sanding sealer this sets a good base,dries fast and is more sandable,i use two coats of sealer, sanding in between coats,i have many times used sanding sealer to achieve a fully filled finish,then finished the project with layers of top coat.

thin to win


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## HowardAcheson (Nov 25, 2011)

It sounds like you may have re-coated without letting the prior coats fully dry. The subsequent coats will tend to seal the undercoats preventing them from getting the oxygen necessary to quickly and fully cure.

At this point, put the items in someplace reasonably warm and let them fully dry and cure.


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