JollyPopper

My Feedback: (6)

What is best to thin oil based polyurethane that has thickened? Would rather not waste it.

tunakuts3d

what does the can say.? Probably Mineral spirits or most any of the stuff labeled "paint thinner" . Just be sure its not " Lacquer " thinner.

RAMFlyer

My Feedback: (65)

Usually what ever is listed on the can to clean the brushes will thin the paint...

JollyPopper

My Feedback: (6)

Sorry, guys, but I trashed the can some years ago. It was in a gallon can and I guess I left the lid loose enough that air entered and formed a solid layer, like a lid, on top of the liquid. When I had occasion to use it again and found the "lid" on the liquid, I carefully removed the "lid", poured the fluid in a glass jar, and trashed the can. The jar has proved to be almost air tight and the stuff has remained in liquid form but has thickened. I only use it to fuel proof firewalls and such so I don't use much. There is about a pint left of the original gallon.

scale only 4 me

My Feedback: (158)

Mineral Spirts

Gray Beard

My Feedback: (-1)

Max, not sure what you are going to use it for but at about 7 bucks a quart the thinner and poly are about the same price. I use a hammer to close down the lid on my stuff and the products don't seem to go bad with time.