1969 BSA Thunderbolt. Have a new chrome tank and am looking for advice on what is the best method for applying the paint as I have had a few differing opinions. One telling me to use a self etching primer then regular primer and another telling me to use a 2part epoxy primer. Both of course after prepping the area to be painted. I have no problem laying down a decent paint just don't want it flaking off on me when I'm done. Thanks in advance.
I've painted quite a few of these tanks and after masking off the chrome panels, unfortunately, you need to use a course emery paper to deeply scratch all the chrome areas to be painted to provide a key for the etch primer. Once you have a couple of layers of etch primer on, it's then down to how you apply a high build primer. I use either a straight high build primer or 2-part epoxy depending on how I'm feeling on the day!
I have painted several A10 gas tanks over 30 years. I have never even attempted to sand the chrome. It is very hard, and laughs at sand paper. I have used self-etching primer, and 2-part epoxy primers and these paints have lasted as long as 30 years (and still look great). For the first time I had a professional restoration shop paint a tank. They too used self-etching primer. The tank is over a year old and looks great. it is of utmost importance that the tank be thoroughly degreased by using chemicals specifically for this purpose.
The standard approach to painting over chrome is to sand the surface first with 120-grit paper to scratch through the chrome and nickel layers in order to provide a key for the paint. Etch primer will not do anything to the chrome and nickel layers because they are highly resistant to the phosphoric acid in the primer.
You can certainly paint directly onto chrome but it's a question of durability over time. To remove any uncertainly, it's best to sand first as it takes very little effort to do this!
Hi,
In my youth I had a B40 with the chrome side panels on the tank and decided that I wanted a chrome tank so I stripped the paint off the rest of the tank.
The chrome was perfect under the paint with not a sign of any abrasive being used. It was not quite as polished as the side panels but definitely not roughened up.
How did BSA paint the tanks?
Dave.
I have just used an etch primer and epoxy paint. Two pack is good but hard to do in ones garage.