Got done doing the famous scratch test to the seat frames I painted out in my garage two weeks ago in 40 degree weather. The paint was Rustoleum (non industrial) mixed with mineral spirits just to keep paint thin and workable (roll and brushable) in the cool weather. The only prep work done to these seat frames was using a wire wheel to hit the heavy rust spots I could get to which wasnt much. Then I painted over bare metal and rust with no primering done. Now after the two weeks even though the weather has not been above the 40's they are perfectly dry. Some areas that I scratched with my fingernail test peeled right off which was where the paint went on very thin and the metal underneath was almost the texture of glass very smooth. Other areas I scraped and scraped and the paint never came off but just got a dull appearance which any paint would with the pressure and force I was using. So this leads me to believe that with the proper prep like roughing up the metal or if your going over a previous paint job roughing the paint that this paint will stick to anything. As well as getting a decent layer of paint put down maybe? This test was only done on some seat frames that will be covered in the next few weeks anyhow. I figured why not give it a try and stop some rust in the process. Like I said before there was virtually no prep done except wire wheeling some heavy rust That I could get at. I put it on in one coat and with no wet sanding afterwards. Jay (Until the next thing that gets the Rustoleum treatment) Will post results!