It is always satisfying to report a new technique or "fix" that works to help others solve the problems we all encounter in restoring/keeping these old classics running. It is not so satisfying, but helpful to report a technique or fix that does not work, so others who might conceive of the same procedure do not waste their time and resources.
I have been experimenting with a technique to rattle can spray paint the raised letter tank badges (Atlas/Dommie). the technique works in principle, but fails because I have not been able to get satisfactory paint adhesion to the chrome plate on the background plane using rattle can paint.
first, an explanation of the spray technique which produces spray smooth finish on the background, with razor sharp demarcation to the chrome finish of the raised letter "Norton" script. I used a narrow (3/16) wide artist brush, with short (1/4 inch) stiff bristles, and masked the sides and top of the raised letters with a coat of Cosmolene (grease/ wax mixture).
The rest of the badge was painters tape masked. I then rattle can sprayed self etching primer over the raised letter area, followed by rattle can gloss black. Allowing the paint to fully dry (1 entire day in the Texas sun, plus overnight), I then used an exacto knife to score the paint film around the base of the raised letter script. Next, I washed away the unwanted paint off the raised letters using detergent and help from an old tooth brush. The paint over the mask came away easily with a sharp line of demarcation to the background. Perfect!
Problem! The background paint could be easily peeled off as well...the self etching primer not adhering to the chrome. Next, using a jeweler's file, I cross-hatch scored the background plane until it was near sandpaper texture, and repeated the above procedure. This time I obtained better adhesion, but the background paint could still be peeled off with my fingernail.
Giving up on this technique, I used an oil based enamel, direct to metal, and brush painted the background, using a toothpick to daub paint into the tight areas between letters. Adhesion with oil based enamel was good, and it should be durable.
I cleaned the area to be painted with lacquer thinner prior to spray or brush painting. Either I am doing something wrong with the rattle can paints, or they are unsuitable for use over chrome ( even when scuffed up).
If anyone can help with the adhesion problem, the Cosmolene mask can be a good technique to spray paint tank badges.
PS: I scuffed up the area where the rubber knee pads are bonded. Anyone know a good adhesive for that job?