Hi everyone. I’m working on doing a custom paint job on an old HO scale Atlas S2 made in Austria. I stripped the paint off the body shell and cast metal chassis with 91% rubbing alcohol which worked well.
But my question is, what is the best way to primer and paint the cast metal chassis? I feel like ordinary paint will just scratch and chip off. I am going to airbrush the plastic shell with either Testors or Model Master gloss black enamel. (Anyone have other suggestions?) How should I primer the chassis so the final coat doesn’t chip off easily? I was thinking of scuffing up the smooth metal with fine-grit sandpaper or emery cloth but there are a lot of nooks and crannies. Let me know!
If you are not hesitant about using solvent based paints, I suggest Scale Coat II. The adhesion and gloss level are both excellent. Scale Coat II’s primer performs well in leveling a surface.
For the metal chassis, Scale Coat1 works very well on metal surfaces without primer.
The trick in painting metal of any kind, brass, zamac, steel, what ever is to get the paint to stick. Metal is smooth and glossy offering little tooth for the paint to bond to, and is often oily or greasy. Surface preparation is important. Start with a good wash in hot soapy water. Rinse really well. Then soak the metal in a mild acid, (supermarket vinegar works for me) for a hour or so, or until you can see a change in the surface color. Rinse well and dry thoroughly, over night at least. Don’t touch the metal with your bare hands, your fingerprints prevent the paint from sticking. Then I use either Krylon or Rustoleum auto primer in a rattle can. The auto primers are marketed to real car mechanics who need them to stick to not-so-clean and somewhat greasy auto parts. As a result of competition, the auto primers have the best stick-to-metal chemistry known to man. They come in three colors, dark gray to go under dark colors, light gray to go under light colors and red to go under red. Once you have a good prime coat on and dry, you can use any kind of paint on top of it.
I don’t pay special attention to frames because I’m pretty much the only one that sees them, so I often paint them with a brush. Some will get the spray if the loco is up to that. I work on steam, often very old steam, so I usually work on the powertrain first before painting it, and I don’t remove the powertrain for painting. I obviously lubricate when ALL is done, not before.
In all cases, I do follow the steps mentioned by others (clean, prime, paint). I use Vallejo primer, and cover with a good acrylic paint. Floquil used to sell the best primer… I usually paint black or grimy black. I don’t worry about scratches - if they ever happen, I will do touch ups with… a brush.
Ah, as usual, I was not paying attention. I would proceed like I do for metal boilers on a steam engine: Strip (unless the original paint looks Ok), clean with alcohol, prime and airbrush. Did that on an old Fleishmann Baldwin switcher about 8 years ago. All metal, no chipping so far…
. This is prior to stripping the old paint.