I have light rust on my frame rails and moderate (surface) on my heavy iron parts (suspension, drive shaft, axles, etc.). I plan on treating it by degreasing and cleaning, wire brushing, rust converter/encapsulator (Black Star - converts rust to a polymer coating), POR-15 frame paint, and then undercoating.

I don't want to get the converter/encapsulator/paint on suspension threads, bolts (for future service), and wanted to know if anyone has tried putting grease, rust penetrator, etc. on bolts, threads, etc. as a method to prevent paint, undercoating, etc. from adhering while spraying the underbody?

If so, which product is recommended to be put on parts that are not to be treated/painted? Can it be put on bushings?

Thanks,
Josh

 

Why not wrap them with tape?

 

thought about tape but figured since the bolts and threads have rust i could kill two birds with one stone. also, figured i could get more accurate with a grease tip and/or small q-tip or brush.