View Full Version : Polyurethane in Humid Conditions

Kurt Aebi
07-19-2005, 12:52 PM
I know that when the Humidity is high, Polyurethane Varnish takes a real long time to cure.

What I was wondering was if I could add some Japan Drier or maybe Naptha to the polyurethane (oil based) to speed up the drying time when the humidity is high?

Right now the dew point and the humidity level are the same and the air is so thick, you could cut it with a knife. I have only to put another 2 coats of polyurethane on the walls and ceiling to finish the living room remodel and I want to get that done before next Wed. when th ecarpet is to be installed (don't want to drip any poly on the new carpet!)

Thanks, in advance - I know you experts will come through!

David Wilson
07-19-2005, 2:39 PM

Don't know about adding anything to poly but might suggest cranking up the AC which will lower the humidity in the house.

Bob Smalser
07-19-2005, 2:46 PM
Add a couple tablespoons of Japan Drier to the pint can, if it's an oil-based finish.

Don't overdo it, however, as it makes the varnish more brittle and it will fail quicker.

Kurt Aebi
07-19-2005, 3:16 PM
Thanks, Bob
I will try it - I have a couple of coats already applied, so I think it being a little "weaker" or brittle, shouldn't create much of a problem - but I'll err on the light side of teh drier to be safe.


Already thought of that and the odor from the poly just about killed me.

Phil Phelps
07-20-2005, 8:32 AM
A long time ago in a far away land, I used to refinish wooden headed golf clubs. One of the "secrets" was to place a pail of water next to a heat lamp for the curing of the head once it was dipped in the clear urethane. You can hasten the driying time but you can't rush the cureing time.