I have heard very different opinions on weather painting a helm will effect the safety or survivability, other than that I'm a decent diy'r and so what grit of sand paper, what paint, and clear coat should i use?
Well if ya look like ya just stepped out of Pathfinder, that would be cool for the whole Iron Horse type of thing, and ya have to weather proof it because helms leak like sieves, most of em are just riveted together.
I would assume hes talking about a helmet? And I've heard the manufacturer's recommend not painting the helmet or modifying it in any way, whether it actually affects the survivability or not I wouldn't know.
I'd suggest getting information from your helmet manufacturer. I know firemen's helmets by Cairns can be repainted safely. They even provide you with the preferred paint brand and colors. I would assume that painting a motorcycle helmet wouldn't be any more destructive than painting a firefighters safety helmet. After all, the manufacturer had to use a paint of some kind.
I suspect 'helm' refers to a metal helmet from a suit of armour.....????
Is so, automotive finishes would work...... so would Tremclad. I don't think protection is a factor, as it would have almost none when used as head protection in a crash.