So I recently bought an old frame with the intention of restoring it. First job: stripping off the paint.
I bought some thick paint stripper, focus' own brand version of nitromors, thinking I'd save a few quid, and started getting to work.
A previous owner had decided they wanted a change of colour and just decided to paint right over the top of the old coat, so there's a good few layers. The paint stripper only managed to get rid of this top coat.
The aim is to get back to bare metal and work from there.
The original paint may well be powder-coat rather than actual paint, and far more difficult to budge as a result - Nitromors-type stuff won't even look at it.
+1 for the suggestion of a professional strip and paint, they should be able to get any old finish off.
"Not so much a religion as a savings club for people who think Star Trek's a documentary"
- Marcus Brigstocke on Scientology