# using propane to retard curing in paint cans



## _Ogre (Feb 1, 2013)

_Ogre said:


> We all have a propane torch, fill the air space with propane.
> That said, I buy the small bottles of titebond and polyurethane glue


i wanted to expand on my use of propane to retard skinning or curing of polyurethane.
propane is heavier than air and will settle out in low pockets. i was doing a little polyurethane finishing, i had poured the poly in another container to keep from contaminating the new one gallon can and had an oz or so left over. my pictures are time stamped in the lower right hand corner

1st pic mar 24 2:51pm is fogging propane in the paint container. i covered it with with plywood as my furnace blows over my workbench










2nd pic. 6 days later mar 30 @ 3:09pm. no skinning or drying that i could see










3rd pic. mar 30 @ 4:28pm. in theory the plywood could have sealed the container, highly unlikely
i stuck a mixing stick under the plywood to vent the container, but not allow the furnace to blow off the propane










4th pic. mar 31 @ 11:23am. still no skinning or noticeable thickening










i'm gonna leave the container for a couple more days and then use the polyurethane on a door i'm refinishing


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## John Smith_inFL (Jul 4, 2018)

it might depend on the product you are working with.
I haven't had much success with propane from the bottle torch.
I have a Tig welder, so an unlimited supply of argon gas.
Epifanes Spar Varnish is notorious for skinning over. (which a lot of folks here don't use). And I only use argon to seal the can with. It often pays off to experiment with things to see what works (and doesn't) in your climatic conditions.
the true test of putting a substance in a can of finish can only be found after 6 - 12 months of undisturbed storage.


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## GeorgeC (Jul 30, 2008)

If nothing else is available use your own breath. Exhale into the can before closing.

George


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## Dave McCann (Jun 21, 2020)

GeorgeC said:


> If nothing else is available use your own breath. Exhale into the can before closing.
> 
> George


If nothing else, exhaling into the container will add moisture, while slightly reducing the oxygen.


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