I second against expanding foam. I used it to fill my AR and it ended up leaking out of every imaginable point where the hot glue wasn't 100% there and ballooned out the sides. It took a LOT of pressing the sides in and holding with clamps to get it remotely close to how it was supposed to look. My biggest mistake, though, was not resining first....I wouldn't use expanding foam inside them, it has a tendancy to adhere to the paper really well, and then shrink, sucking all the paper in with it. What I would suggest doing is after you've resin'd the outside of it to give it some strength, is carefully line the inside of it with fiberglass that is long enough to protrude into the helmet and adhere it down to the inside of the dome as well, so it looks like an 'L'. Then fill the fin with resin or rondo and resin down the root of the fiberglass cloth. That will give you some incredible strength to them.
Thanks for the help I finished the pep but it turns out that it's too small. If I have my head close to center of helmet, my eyes and ears are like 7cm (2.75in) below the eye holes and ear pieces(?). So If I increase the height by 12cm (4.7in) should be good enough? I don't want the helmet to be too huge. The helmet design itself seems a bit out of proportion.
EDIT: I tried putting it on again and by tilding in more and it seems it's a good fit. One fin is a bit higher, will I able to twist it down a couple of degrees after resining by using a heat gun?
By visor, do you mean the Up-Armor? It's the third armor permutation of the CQC (If you count the "default" one too), with the thing over the top of the helmet and the box on the right ear?
If yes, then that IS in the http://405th.4shared.com db. It's under Reach -> Helmet -> Attachment -> UA -> UA [CQ] (Reach CQC helmet attach MS7).pdo
Some of the other ones in that folder might work as well, but that one is labeled to be for CQC so give it a try!
As for the HUL, it's in that Attachment folder, just leaf through the HUL folders and pick one you like.
Most helmets are meant to have the attachments seperate, so you can do what you want with them!
You need to fix it as you're going, it depends on the piece, but you definitely need to fix it prior to resining it.I'm noticing that as I am peping the helmet the paper is warping and I am wondering in what stage do i fix that? do i fix it after i fiber glass and sand/fill them out or do they need to be fixed in this stage and if so how do I do that?
Thanks, that really cleared things up for me. I have one more short question. Is there any particular order I should pep the helmet in? My last attempt led to some distortion, and I figured I had assembled it starting at the wrong place. I started at the very top of the helmet, working my way down. Should I go by the numbers on the flaps, or is there another way? Thanks.