A lot more heat than light in some of the posts on this thread. Thanks to atblis for posting MSDS.
Summary for non-MSDS readers:
1. Old Gunscrubber=Chlorinated=Trichloroethylene. I have an old can I must have bought 15 or 20 years ago. I only use it to clean the inside of my Ruger .22 auto. Trichloroethylene is pretty harsh stuff, typically melts plastics etc, and is known to be carcinogenic. It used to be widely used as an industrial solvent but now most industry safety people either ban it or watch it very carefully.
2. New Gunscrubber=non-chlorinated=Hexane and Isopropyl Alchohol. Still strong stuff but Hexane is not seen as the health threat that Trichlor is. No personal experience on how it interacts with plastic or wood finish, but I wouldn't let it touch the stocks of a gun I cared about.
3. Brake Cleaner = a generic name for a strong cleaning solvent, that you won't know for sure what is in it without reading that manufacturer's MSDS. Trichlor was popular in the old days, dunno if anyone still sells it what with product liability. One popular brand is mostly Acetone with a little methanol and a very little MEK (methyl ethyl ketone). Very strong stuff. Another is mostly Heptane with some ethanol. Another says "petroleum solvent" and alcohol -- petroleum solvent leaves it pretty open, doesn't it?
The MSDS of many of these products shows chemicals that would remind you of paint thinner or even stripper, so gun stock finishes beware.
If you have worked a lot with solvents, you probably know what you are doing, take your chances.
If you haven't -- please use any of these products carefully, even the milder ones may damage finishes. And none of them are good to breathe a lot of fumes.....
My personal recommendation is to save gun scrubber, or acetone (I always have some around) or similar tough solvents, for "metal only" situations and only use them when milder solvents like Hoppe's #9 or the like just aren't up to the job.
