Wanting to make a Corinthian helmet out of plastic

[Skallagrim]

Hey folks,

I got a plastic rain barrel recently and would like to use some of it to make a pseudo Corinthian helmet. Since I haven't worked with plastic before and the only helmets I've made were leather ones, any advice would be highly appreciated.

Basically what I'm aiming at is something like this: http://www.kultofathena.com/product.asp ... n+A+Helmet

However, historical correctness is not an issue (well duh, using plastic ), as it's intended to be a sparring helmet. For that purpose I plan to add steel mesh behind the openings to make it safe. My main problem is how do I make the bowl shape?
I was thinking about taking a flat piece, heating it up to make it pliable and then trying to sink and raise it into the shape, like it's done with metal helmets. I'm not particularly confident in my skills and my available tools though and I doubt that the end result would look even halfway decent.

So it might be easier to make it either out of four pieces, with two straps connecting them, like this http://www.kultofathena.com/product.asp ... nhelm+%231, or to make it out of two halves. I would try to connect the pieces by welding the plastic in some places and using rivets wherever possible.

That's just my ideas so far, I might be on the wrong track. Does anyone have any suggestions or maybe even a pattern / template?

[Gunter Haller]

You could try nesting the heated plastic between two appropriately sized bowls. Poof, dome! =)

Look at the writing on your barrel and see what type of plastic you have. If your plastic is ABS, welding can be accomplished simply by melting scraps in acetone (nail polish remover) until it forms a paste and then applying between two roughed up surfaces. It will melt the plastic and re-solidify into a single piece.

If you have HDPE... rivets are a good choice. The whole purpose of the -PE plastics was to provide an un-reactive surface, which means glues/chemical welding become a problem.

[Skallagrim]

Yes, I was already considering the idea of forming a dome with two bowls and then squeeze that into an elliptical shape, I just don't have bowls in the right sizes at the moment. Good suggestion though.

What I got is one half of a rain barrel and unfortunately I cannot find any writing on that part which says what kind of plastic it is. I assume it's polyethylene but I'm not 100% positive.
I was thinking about using a soldering iron and some small bits of the same plastic in an attempt to weld it but I'm not sure if that would work. Riveting on the other hand should be fine.

I can just experiment with welding on small pieces to see if that's possible. My main problem at the moment is the pattern. I remember when I made two leather helmets I was struggling immensely with getting the shape right. My understanding of geometry sucks, that's probably why...