So I'm currently working on making Screaming Mantis from MGS4:
http://images.wikia.com/metalgear/images/c/c8/ScreamingMantisMGS4.jpg

I'm going to start working on the Helmet portion soon and I have two options for going about it but I'm not sure which would be the best so I'm basically putting this here to pick other peoples brains really.

The two options I am toying with are:

a) To make a Pepakura version out of cardstock and then fiberglass this. I currently have a file for a daft punk Helmet which is similar which I will need to modify to make it more exact but it's close enough.

b) Use expanding foam to sculpt a base then add finer detail in either clay or two part epoxy resin.

I've heard if I use technique A and I fiberglass on the inside I can directly rotocast the helmet but I can only use this mould once whereas with technique B I can make a silicone mould and use this multiple times if I stuff up my rotocasting

Also it's worth noting that Fiberglassing is new for me but so is expanding foam so this is the other dilema. I've used Pepakura and clays before though

Thanks in advance for looking - any thoughts on this would be greatly appreciated even if it's just personal experiences

I can't give you much advice (you've probably been to all the same prop and armour tutorials I have XD) but it might be worth looking at Xae's Briareos costume:

http://www.cosplayisland.co.uk/costume/view/5518

as he did that with hot glue and layers of latex which is another option that might work for you ^^

Yeah xaerael always documents stuff so well. I do have a lot latex and hot glue lying around from another project so might give that a shot!

And yeah been lurking RPF a lot so getting lots of details from there

Thanks

I'd go in another direction and probably try heat-formed plastic. It depends a bit on how you're planning vision out of that thing! I would look at a clear thermoplastic sheet (you can get them at a lot of larger art and model shops) and motorcycle visor tint sheet to get the colour - that way you'd be able to see through the full helmet (if darkly) although you risk your own face being visible through it too, but you could use a balaclava to cover everything but your eyes underneath it.

I haven't thermoformed the stuff myself, but I know it's what Tab used on his Crystal Siegfried armour, so it's definitely possible, and I believe he only used a heat gun to do it - so no fancy equipment needed.

If you have other ideas on seeing out of it (and I will DM you later about that) I'd honestly take a look at doing it out of Plastazote and PVA, like TheKillingDoll's Priss armour. It's also heat formable and you can make it look nice and smooth, plus it's friendly to work with.

Xae would tell you to avoid fibreglass like the plague. He tells everyone to avoid fibreglass like the plague. It's not friendly stuff at all and you need really good Personal Protection Equipment to even consider using it safely, so look into every other simpler and safer method first >_<

Cool I will avoid the Fiberglass. I wasn't very keen on the idea of Fiberglass because I've heard it's nasty nasty stuff but I kept seeing it pop up in build tutorials that I was kinda intrigued by everyones fasination for it

I love the idea of using tinted thermosetting plastic. I'd not even thought of that. I used wonderflex in the passed and had a bad experience with it because I burnt it. I think it's more to do with the fact that my heat gun was way too powerful for it. I also had the same problem with Plastazote but I've been planning to buy a new heat gun for a while so as long as I'm careful I can avoid that Especially since I've seen all the wonderful things people make with it - I mean I attempted using it a long time ago as well so all the new stuff I've learnt should help.

And I don't mind my face being seen - it's a better option then the ones I had thought of. So far all I could think of was having the helmet flip up like it is after the boss battle for most moving about. Then having it pulled down just for the masquerade and having small eyeholes that you kinda pop out. I will get looking for some visors that might be a good base on eBay and if that doesn't yeild anything I'll get heading to a good arts and craft store near me

Thanks for the help

Fibreglass is a lot of glue. Having used it a bit, it's okay in a well ventilated area with gloves - but get a book on it to be properly safe with it (mixing things wrong is a bad idea; think a more complex epoxy with very specific measurements).

The fact you might want to make more than one means yeah, use this as a last resort, since if something goes wrong when making the final piece it'll be starting from scratch doing a mould (one reason I'm avoiding it for my current costume).

You can get reusable moulds that work with fibreglass things, but just need hardier material. Helmets are a pain though.

Thank you for the advice. Something more complicate then Epoxy sounds out of my league to be honest. Unless its a 1 to 1 ratio I mess up so this is just another reason to avoid fiberglass by the sounds of it so thank you for the advice.