Quote: I think GTSDAVE's advice on surface prep is sound, but I would be hesitant to thin with laquer thinner simply because it's not the recommended thinner from the manufacturer. Gotta defer to the Rustoleum chemists IMHO. I'm convinced at this point that the troubles folks are having are not a "hardness" problem, rather an adherence problem. My dilution ratio was significantly higher than the average (~45%), so you would think that it would take significantly longer for my paint to dry, yet it's hard as stone after only one week - unscratchable. I might be wrong here, but I think those having trouble started with a primer base. Did the primer coat folks sand down the primer coat before starting, or just wipe down with cleaner before starting? Maybe a primer coat alone isn't rough enough for the paint grip/adhere? Bare/clean metal painters, are you having problems? I know with products like POR15, a metal prep/etcher is needed, something to "rough up" the metal enough to give the POR/paint something to grab onto. Hope this helps.
i totally agree. use mineral spirits, NOT laquir thinner with the rust paint, it is mineral spirits based and NEEDS to be thinned with mineral spirits. let's keep one thing in mind here, the mineral spirits mixed with the paint allows for a thinner layer of paint to be applied, that will actually dry faster then straight paint in a thick layer. the mineral spirits increase the pot life, and tack life of the paint and don't really effect the overall drying time. after 6-8 hours, even if you thinned with mineral spirits at 80%, the paint will "flash" and dry. the solvent (in this case being mineral spirits) evaporates from the paint in 6-8 hours, from then on it is the paint that dries, very little of the "flashing" occurs after that time, then it is the paint that actually dries, and that is a constant. remember your not comparing apples with apples here, how hard the paint dries in the end is soley based on the paint it self. on the other hand, when you paint using a enamel that uses a hardner, the hardner causes a chemical reaction with the paint that forces it to flash faster. it's like body filler, eventually straight filler will harden, but the hardner speeds this process. i think all the adhesion issues and scratch tests are related to surface prep, i allways sand with no more than 600grit when prepping a surface to get the paint to adhere. then you have to also clean the surface. even though you sand, you don't remove all surface contaminents, if there is wax for example on the paint, sanding will not totally remove it. i'm sure that if you prep properlly with the right paper, and don't go too fine with the prep, and you really clean the surface well with mineral spirits there should be no issues with adhesion. we can see some members have issues and others do not, the paint is the same, and the only varaible is surface prep, regardless of the ratio of mineral spirits. as a test, if you really feel it necessary, if you paint with straight paint, and paint thinned with mineral spirits at 50%, assuming you could get the same thickness in layers of paint, i'd bet they would dry roughly at the same rate after the first hour. if you soak a rag with mineral spirits, and whipe the car down, the mineral spirits will evoperate completely in about 10 mins. same happens in the paint. then mineral spirits slightly increases the initial drying time, allows you to work with thinner paint strictly due to the thinner viscosity of the paint, and allows the paint to "self-level" better then just straight paint. rant out
P.S. - EXIT1965- quit painting test areas and paint that damm car allready!!!!! next pic i want to see is a done car!!!! lol
rant out 
