Going to open a whole big can of worms here, I cannot think this one has not been opened before !!!!!!
My Ageing Schuberth C2 had the misfortune for the headlining bit of the trim fall apart, I suppose its just age and head sweat, anyway, as I like the helmet so much, decided to fit another lining I had lying about. Then I thought, whilst at it, why not change the colour, its was red, but quite scratched and chipped. Lots of internet searching later as to whether I can paint it or not did not give me the answer I was looking for, so attended a few car paint shops and asked all the questions, as its made from fibreglass and other bits, not polycarbonate, told OK to paint with a water base paint, so off I went and re painted it Silver (that's the lid of the worms loosened !!!)
It took me about a week to do, so decided in the interim to get another cheap helmet to use, now I am, by my own admission, tight (wife says I squeak when I walk, I say its my plastic knee !!!!) any way, to cut a long story short, I bid on an HJC crash helmet on flebay, won. When it arrived, except for a few chips, looked fine, stripped it out, washed the linings and inspected the shell, no damage I could see. all back together and its fine, label inside states 2013, looks hardly used, all this for the whole sum of £2.20p. It has served its purpose and now will be a standby crash helmet (that's the can now open, 2nd hand crash helmets).
The schuberth is just drying nicely before I use it again, like to give new paint a week to harden, it looks like it was made that colour, and by the way, if you have never stripped down something like a C2, be prepared for a lot of parts, could not believe how well put together it is.
I expect to have negative and positive comments regarding painting a lid, and wearing 2nd hand ones, but should produce a good thread.