I hung my parts like that while spraying some epoxy. Made for some interesting spraying as I never tried to paint a "moving" target before. How'd you keep them from spinning?
I just use my hand and hold the parts. Sometimes there are studs you can grab or areas on the backsides of the parts you can grab. Just gotta get creative!
I will hang parts just like you do but use a coat hangar or something similar with a hooked end to keep the part steady while I spray. Also works well to move the part around a little to get the edges coated.
