Fiberglass helmet and thinner... Bad idea???

Grettings and salutions ye who are far wiser than me...
I seek your consultation on the matter of a DP '95 recast lid and utilization of thinner on said helmet.

Basically I aquired a lid off e-bay recently and it arrived in far rougher condition than I had hoped (I wanted at least 1 bucket to work on while I wait for my metal one to be cast). It is going to need some bondo and some sanding work... but I've come to discover there are just too many damn layers of paint on this bucket to make sanding the "quick" course of action to get to a pre-bondo-needed condition.

Therefore I pose the question: Can I utilize a paint thinner or remover to said fiberglass bucket without doing damage to its structure? Or... is sanding the only way to accomplish this task before moving to the bondo blemish-fixer stage?

I leave this inquiry in your capable hands oh geniuses of the Mandalorian garb!

Thank you all in advance for your time and knowledge.

Grendel Prime
"It's not JUST a job... it's a freaking galactic ADVENTURE!"

You could use acetone SPARINGLY to remove the paint. The paint will come right off. It won't eat the helmet but if you were to rubb too hard on a corner you might lose some of the sharpness of detail. If the paint & bondo are adhering fine, I would just give it a good sanding, apply scratch fill primer & then see what kind of work needs to be done. You shouldn't have to take all of the old paint off.

If the helmet is gel-coated fiberglass, then you could use anything on it without worry. The best thing I found to remove old paint from fiberglass, is Airplane stripper, in the blue spray can. You can find it at most automotive stores. Spray it on heavy, let it sit for about a half-hour, then wipe everything right away. Use some acetone or laquer thinner to clean-up any residue. You probably won't be able to get it all out of any fine details, but you'll do what you need to.

acetone shouldnt hurt it even though thats what i use to clean my gel coat gun. once it hardens its pretty tough to remove. personally i would go the sanding route as mentioned before.