Hard coat merc helmet

[jardane]

I have been working on a set of merc armor and i could use some advice. Right now my helmet is just cardboard and sanded Spackle but i want to give it a nice hard coat. I don't know what process would give me the best results.

here is what my helmet looks like right now (this was taken before i sanded it)

 

[JSmails]

I think most of these are done in cardboard, then resined on the outside, fiber glassed on the inside, then bondo'd to smooth the outside and harden it.

The thing you've done, I suppose you could go straight to a smoothing coat of bondo on the outside. That'll harden it up. Or glass the inside.

 

[bobawannabe]

I'm going to be at this point soon, I'm thinking about fibreglass inside and a resin outer, then starting with filler. Once painted, would you seal the top paint layer?