???casting resin (like smooth-on)/paper mache clay/rid fiberglass fumes???

http://www.therpf.com/f24/casting-resin-like-smooth-paper-mache-clay-169807/

Can anyone help me?

I would recommend Smooth On's Onyx resin for casting your helmet. Very versatile and doesn't give off noxious fumes. I use it for all of my helmets.

I like onyx, and smooth cast 300 and 325. Onyx is pure black and cannot be tinted. If you use a 1 to 1 resin it is easy to use. If its your first time with resin I would recommend a longer working time version. Resin can have bad fumes, but most of them only fume when curing and you would have to stand over the cast and sniff the fumes for it to be very harmful.

Yes!! Fiberglass gives of harmful vapor and I recommend a nosh mask with any fiberglass, and it can be difficult to work with at times. I would try several small scale project to get the hang of it before jumping to something large.

Just keep in mind anything with a two part catalyst, has the potential to be harmful to you. Use proper safety and you will be fine.