Metal prep and painting

Charles is right. You're not too dumb. Once one gets into the world of automotive paints, it's a nightmare to be able to negotiate the maze. Even the experts are not completely aware of all products and sometimes don't agree on the ones they are aware of. There are so many different manufacturers, different lines of products, different chemistries, some of which are not compatible with each other, plus safety issues that it becomes almost impossible for a beginner to decide on anything. Futhermore, it is always in the best interest of the salesmen to push their own products rather than a competitor's. It is likely that what gets recommended is what is "most popular" with the local autobody shops, which is not necessarily in the best interest of the backyard guy wanting to paint his tractor. In addition, legitimate safety concerns are likely to be minimized if they are addressed at all at the salesmen's counters. So don't feel bad - you are definitely not alone.

One thing I recommend is for you to reconsider putting any kind of etch primer on top of a plastic body filler, if that's what you're doing, especially for future work. I don't believe that is generally recommended because of the acid in the etch product. In my way of thinking any kind of "etch" product should be applied to bare metal only. However, check the SEM label instructions to see if that is addressed at all.

In my opinion, for you to select a surfacer (filler primer) or a topcoat you will need to decide on a major fork in the decision road. That deals with safety concerning chemicals called isocyanates and the use of hardeners that contain them. Safely dealing with isocyanates requires a positive pressure, fresh air respirator. These cost $400 - $600 at the low end of available equipment. If you have or wish to purchase or can borrow such equipment, the recommend products go in one direction - to the urethanes requiring hardener additives. Otherwise, the recommendations are in a totally different direction - to the enamels and lacquer-based products that do not require such additives. Or to the "tractor enamels" and hardware store enamels like Rustoleum, etc. Marlinm51 just down below is also dealing with the same issue. See my post to him today just before this one concerning my suggestion on some DuPont products that can be used w/o fresh air equipment. I can also recommend similar non-iso PPG products if you want to investigate the matter further. The urethane type products are more modern and are "better" for the most part. But they are not worth risking your health over by using improper safety equipment. Others will disagree but the final decision on that has to be yours. Just read all the fine print on any additive labels and check out the Material Safety Data Sheets (MSDS) on any additives for the recommended safety equipment prior to your decision.

Rod

I have sprayed acrylic enamels, lacquers, and isocyanates. The latter is nearly bullet proof against runs if a gun is set right. (In a class with a professional teacher.)

I am getting ready to paint my old 1949 Chevrolet one ton truck. I figure that paint will show me all of the blemishes, dents, and dings that I have missed, so figure on repainting in a few years anyway. Because of that and that I may want to switch colors, I really think that I will just go with Rustoleum paint from the hardware store. This old 1949 is a beater/driver and not a show vehicle, so this will save on cost too as well as not having to worry about health issues as much.

I know a lot of fellows would say not to do it unless you do it right, but there is also fun in doing it more often.

Again, thanks for the info.

You are not too dumb to understand! Get on this site and search the archives and you will be real smart real soon.

Also some books on painting out there.