Is their any other way to prep the frame for paint other than sandblasting?
Short answer, Yes. You want to prep for both mechanical adhesion (tooth), and chemical adhesion. Depending on what coating your planning on applying, the manufacturer of that coating will have "Tech" sheets advising surface prep for different substrates. Plastics, or non metallic substrates tend to get saturated with oils, & contaminants that don't get along too well with Urethane based paint systems, prepping them can be a bit of a chore. Usually repeated washings with hot soapy water, followed by hot water rinses gets them pretty clean, a mixture of vinegar, or lemon juice in water works well if there is a lot of oil to leach out. I always avoid solvent based was & grease removers when prepping plastic parts, they tend to soak up solvents & hold onto them. I talked to a factory rep from Duracoat about a month ago, and he recommended light sanding on smooth sections with #600. I always sanded with #400, or scuffed with a red scotchbrite. But whatever coating, or paint you shoot will have it's own reommendations.Is their any other way to prep the frame for paint other than sandblasting?