I searched this forum for original finish on K2 master cylinder and found many recommendations for restoration, most missed the technically correct answers. I have 20 years exp as an industrial technical paint rep. When consumers blame the paint, my job was to help them out. So painting a master cylinder with brake fluid resistance? EPOXY comes in single pak and 2 pak, only a 2 pak will be resistant to Br fluid.
Yes VHT calliper paint is somewhat resistant, probably epoxy (obviously single pak). I use it around the bike but would not do a master cyl with it. RUSTOLEUM best spray packs because the can be used upside down giving equal thickness, not thinners loaded when used upside down and a good quality paint. The only paint I would use in brake fluid environment is 2 Pak Polyurethane. Now this product comes in 2 main styles , Acrylic or polyester/ (Linear which relates to the molecular chain)
Auto is designed as Acrylic 2 Pak baked in an oven to speed up turn around times and it can be buffed to fix any "runs " etc. Marine top shelf paints are Linear poly's which give the best finish off the gun ( most expensive). This is the only coating I would put on a Motorcycle master cylinder. Also epoxy paint is not UV stable compared to Poly 2 Pak. I suggest a Google look at 2 Pak Polyurethane and check the manufactures data sheet. Some won't say if Acrylic or Polyester which usually means Acrylic. (cheaper to make)
My full doco on this subject was done 15 years ago with a US chemist so I can't find the link now.
Hope this helps some.
