You can also thin solvent-based poly by adding up to 10 percent mineral spirits, but only if you live in a state that allows it. Some East Coast states and California prohibit users from adding solvents after the can is opened. In that case, you’ll have to recycle the old stuff and buy a fresh can.
–Family Handyman, October 2009, p. 75
I figure FM is just covering their butts legally, but I found this statement to be mindboggling. First. how does anyone propose to enforce such a law? Do the state EPAs have special sniffers that can tell the difference between various organic solvents? Are they going to do warrantless surprise searches to look for tampered polyurethane? Has anyone ever been prosecuted under such a law?
Second, what were they thinking? What is the purpose of such a law? Was it lobbied for by poly manufacturers to move more product? Wouldn’t buying a new can release just as much solvent into the air, plus incur the ecological costs of producing another and disposing of the old? Somebody fill me in here.
I am certain that virtually nobody in the affected states knew that this law existed. And now that they know it exists, I’d wager that nobody will actually obey it. It’s not like anyone would actually know, unlike Billy Beck’s hypothetical shed. I guess that if you can’t build it, then how you can’t finish it is irrelevant.