i just got my frame back from sandblasting
now what kind of paint should i use
on the frame,thanks keith
If the sandblasting has removed all traces of rust, you should not need any rust conversions or rust encapsulating paints. The sandblast finish is perfect for mechanical adhesion of any good epoxy primer. If you are looking for a good semi-gloss black, SPI epoxy will give you a good durable finish and has UV inhibitors, so once sprayed you should be done.
For prep, I would use a bucket of warm to hot water with a light Dawn soap mix, using a Scotchbrite pad dip in the bucket, scrub an area, and dry with a towel. Move to the next area and repeat, using a slight overlap. Once done, clean with a pre-clean solvent, then tack cloth to remove any lint.
Hopefully you degreased the engine area prior to sandblasting, but I would caution against using lacquer thinner as a cleaning solvent. It evaporates too quickly and risks leaving impurities behind. Use a pre-clean solvent, which is slower to evaporate. The premise behind cleaning with a pre-clean is similar to the wax-on, wax-off. One rag with pre-clean applies, the slow to evaporate solvents will "float" any impurities to the surface where rag number 2 is used to wipe it off. On sheet metal, I usually apply on about a 2' or less square, allow about 15-30 seconds for impurities to float, and then wipe with second cloth. If pre clean is drying before you have a chance to wipe, either use wetter application cloth or smaller area. You want to wipe before drying as otherwise you have floated impurities and once cleaner dries, the impurities are right at the surface, they don't magically disappear......regardless of what you use.
Given the cost of paints, I normally do the pre-clean process at least twice. Good insurance policy to help eliminate chance of fisheye..
On the cheaper cans of lacquer thinner that most hardware stores carry, these are recycled solvents that will contain who knows what. Get the product designed for cleaning the bare metal..
