Yesterday I aquired a windscreen for a Buell M2 motorcycle that had been in an accident. The paint on it is scratched and chipped/flaked off in areas. I'm not worried about the scratched areas, just sand and paint. However, I don't think that I'll be able to get a good transition btwn the existing paint and where it is chipped off for a smooth re-paint.

So... Can anyone recommend a good way to strip the existing paint completely off? I believe that the underlying material is a plastic of some sort, so the stripper must not effect the integrity of that material.

Anyone?

Thanks!

Kevin
Canton, MI

 

Check with any local Body shop. They have to repair plastic bumpers and body parts all the time. Also ask about the type of paint to use. Those flexy/soft parts need a paint that won't crack. Should think that any good shop would answer your questions, IF you don't get there at (there) rush-hour.

 

I haven't done much with plastic parts but if this were a chipped hood on my car I'd just sand them out, progressively working from relatively coarse sandpaper down to 300 grit and feather edgeing each layer of paint so an inch or so of each layer (primer, topcoat etc) showed. I tend to save as much of the original finish as possible if it's not actively peeling off.

Are you concerned that the adhesion between the paint and the plastic has been compromised overall due to the accident -- even beyond where it's flaked and chipped?

 

you should be able to get away with most any chemical stripper also if you want to go that way. Where I work pretty much the only thing we can't use the chemical stripper's on is composite's (fiberglass, carbon fiber, graphite, boron that stuff) I would personally remove it mechanically use sand paper but just to throw out the option you should be able to use the stripper's you find at your local parts store

 

get some air craft stripper from the parts store, the stuff works wonders removing paint

 

I've done some Fairings. Is it a Vetter fairing? If it's not metal or fiberglass, they are PVC if it's a Vetter.

Don't try to use chemicals to remove the paint. It can handle a quick degrease wash, but much more than that the plastic will start to melt and look like Swiss cheese with little craters all over.

You have to keep it cool, stay away from power and just wet sand it by hand. I start around 100 grit and work down to 220 to rough feather. I've found it doesn't take long to smooth things out this way. Once I shoot a couple coats of filler primer and hit it with 400 wet, I know the problem areas I need to work on. Not a big deal to leave the original paint on - not like metal where you have to worry about rust..

The decals they use for pinstriping can be a bear. I boil a pot of 50/50 water and vinigar, soak a towel in it and lay it over the decal till it gets soft. Sometimes they peal right off. Sometimes I have to take a razor blade between the decal and the paint and pull with the other hand. Don't let it cool down or dry out - it'll get really hard, but you just have to use more hot water to get it soft again. Put a piece of tape on one side of the razor and keep that side either up or down while you use it. I've used a razor this way to take super glue off windshields and paint lettering off work trucks and it works great, as long as you don't flip it over.

I've used Bondo and glazing putty to fill in scratches and chips with no problem, just make sure it's clean before applying. I squirt some dishwashing soap in my sandpapaer water, so I can clean while I sand. Again, use plenty of water, this isn't metal.

Major cracks can be fixed by drilling a small hole at the ends of the crack and using epoxy putty on the back side to "weld" it. You have to be creative with the holding jig you make, but I've repaired where the the plastic has cracked and permanently gouged in, this way. Just made a jig to push it back out and let the epoxy harden. Don't push it out too far, it's hard to sand down a plastic high spot.

Napa sells a primer for flexible plastic in a rattle can that does a good job and the two stage paint I've used has never had a problem.