# polyurethane dry time?



## Diana Stone (Mar 13, 2008)

Hi, I am building a table for my 3-toed. Going to use polyurethane to seal the wood. How long after the last coat (3 or 4) should I wait for it to cure before using the table?


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## Josh (Mar 14, 2008)

i'd leave it out in the sun until the fumes are gone


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## bdoyle (Mar 14, 2008)

Hello,

I actually work for a Polyurethane Manufacturer.

There are tons of various types of polyurethane. If you can let us know the brand and type of polyurethane/polyurea you areusing.. I can tell you how long the curing process takes.

Is this Urethane a 100% solids urethane or is it solvent based.

Id shy away from solvent based if possible. They typically can take 5 - 7 days for the solvent to leech out. Depending on the kind of wood your using it can also trap solvent for longer. Temperature plays a big roll in this.

If you can keep the coated wood in the sun or a warm place the solvent will flash off much better then at standard room temp.

To be safe for an animal housing Id suggest 3 to 4x longer then the manufacture states as its functional cure time.


I coated my new enclosure which i just finished last night, with 100% solids polyurethane. Tack free cure time is under 15 minutes and functional cure time is 12 hours at room temp. Food contact grade to be safe for the animal.

I will post pictures soon.


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## Diana Stone (Mar 14, 2008)

bdoyle said:


> Hello,
> 
> I actually work for a Polyurethane Manufacturer.
> 
> ...



I will be doing this in the garage since I am in Washington state and we have not much sun or warmth in March . So I am guessing I will be letting it sit for a week then. The wood will be plywood. Not sure if its solvent based or not. Will look at the can, it is water cleanup if that helps. There was only two kinds at McLendons, indoor and outdoor.


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## bdoyle (Mar 14, 2008)

In all liklihood 5 - 7 days will be plenty of time to allow try time.

consider opening the garage door for 30 min at a time periodicly to allow clean air to come through.

Is there a primer coat being applied or are you painting the polyurethane directly on the wood?...

Primer coats "seal" the wood and allow a stronger bond of the polyurethane to the wood... this seal also forces the polyurethane to cure outwardly through the coating rather then seeping into the wood and attempt to vent the solvent through the wood. Might speed up the solvent release if you did this.


Not to worry though, any way you cut it you should be fine after a week.

You dont want to put your tortoise or any animal in an enclosure until its fully cured though. 

Bring your face close to the coated surface and smell, if you smell anything then solvents are still being released.


if it is just one can that you have ( a 1 part system ) then it is solvent based, and means you will be looking at fumes being emitted so it should be easy to tell when the curing process is completed.


I highly recommend to anyone reading this, to look into 100% solids polyurethane options. They are environmentally sound, do not emit toxic fumes and have a very low VOC content. (Volatile organic compound) which is the main concern when dealing with plastics/polyurethanes and rubber adhesives or epoxy's.

They are most commonly Sprayed onto the surface with airless or pneumatic spray guns.. however Rollable/paintable options are out there.

The pot life on 100% solids can be as little as 10 minutes or as much as 12 hours.


Hope this information helps.

-Blair


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## Itort (Mar 14, 2008)

Blair, Thank you. This info is very valuable to all of us. Thank you again.


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## Jentortmom (Mar 14, 2008)

I wish this was here before I did mine. I used water based polyurathane, I let it sit for a week and a half before using it w/ torts. But I did 10 coats so the wood does not get water damaged. You might want to do more coats then 4, you are putting box turtles in it and it will stay moist in there all the time and you don't want to have to replace the wood. Just a thought.


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## Diana Stone (Mar 14, 2008)

All of you are so helpful. Thank you so much. I think I will be sealing this table with lots of coats and letting it sit for a week in the house. My nose is pretty sensitive so I should be able to tell when its safe.
Again, thanks so much for all your responses.


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