pepkura weapon reinforcement

[pwner50]

Hello everyone! I recently have gone back into prop making, and am stuck on a point in the construction. I am building the HD battle rifle, and the paper that I am using (the heavy one that is intended for this) seems to be a bit flexible. I was thinking of going through the after processes (such as fiberglassing) but I was wandering what is the best method? Should I maybe keep the gun separated into left and right, fiberglass the inside, then put them together and fiberglass the outside? or can I only do it to the outside? Or if there is a better technique to reinforce, I'm all ears.


And I tried making a small skeletal structure on the inside to keep the sides apart, but they aren't very effective.

thanks so much!

 

[Bfranx]

im wondering the same thing, im making an odst pistol and smg.

 

[Shadowshail]

Just an idea to put out there that me and my friend tried was to make the gun and maybe split it somewhere over all into two pieces or even make it but leave a hole for expanding foam, my friend tried it out but he put too much in at once and it poofed the paper out. You can get the foam at Menards and maybe Home Depot....Though if you screw up you'll have to pep another rifle...Just an idea.

 

[dung0beetle]

Skip uses sintra for pep weapons, just turn off the tabs in pepakura. Here's his DC-17 build.

If you can't get sintra (pvc for sale signs are made of the stuff), you can fill the void areas with stacked corrugated cardboard. They don't need to be exactly the shape of the inside, they just need to provide support to keep the weapon from deforming from the weight of the cardstock itself or the fiberglass resin. You can also glue popsicle sticks to the inside of the weapon as you are building it. That will provide strength if you want to fill the inside with expanding foam. The foam will try to push the card away from the stick, so use enough glue to make a full coverage bond, but not enough to saturate the cardstock making the card deform.

 

[Nightshade]

One of the most effective methods of strengthening these particularly difficult (to harden) props is the use of rondo on the piece's interior. Keep your weapon (the BR) in several separate, manageable pieces.

After applying a single (or double) coat of resin to the exterior of each piece, take advantage of their openings in each piece to pour in a 50/50 mixture of Bondo and resin (each with their own respective amounts of hardener) which you can mix together in a plastic cup. Then move the mixture around the inside of the piece as if you were slush-casting a mold (to cover the entire surface of the interior as equally as possible). Each piece may require multiple layers, but one should provide considerable stability. If possible, you can lay in some 2"x8" strips of fiberglass matting over wet rondo on larger, flatter areas (namely, the sides of the BR) for added stability.

If you have added skeletal supports to the inside of the BR, then separating the rifle into a few pieces should not cause noticeable warpage, and, once hardened, they should fit back together easily. They can then be securely attached using rondo-soaked strips of matting.

Here's an example of how you could separate the weapon (barrels and main gun component ignored):

I'm only suggesting the use of several pieces in order to make the hardening process easier.

I hope this helps, and you consider this as a process for effectively hardening the battle rifle

 

[pwner50]

Thanks so much for the input!

My skeletal structure was made of the stronger paper material (card stock I think), so I'll probably remove it. But I do like the idea of Popsicle sticks.

Also, you said start with resin on the exterior. I'm just not sure about the materials, still have to learn about them, but wouldn't that warp the paper inwards? Or is it a light but strong reinforcement chemical?


thanks!

 

[wolfeborne]

Anyone ever try highgrade expanding foam for this. I was thinking of trying it and it would have the upside of floating.

 

[Nightshade]

A single (or double) coat of resin on the outside of your weapon will not warp it at all. In fact, it will both strengthen it's shape while sealing the cardstock (and thus preparing it for the internal rondo application). Also, a single coat will not add enough new weight to the piece to cause any real warpage

 

[nrettenmaier]

Smoothcast 320 is probably the easiest way to do it. Its basically a two part plastic that you mix as a liquid and will harden into plastic. I've never tried the rondo method but I assume this way is easier because the smoothcast 320 is a lot less viscous so it will be easier to work with. All you have to do is cut a hole in your weapon, pour some in, and then just move it around until it dries. It did this with a coveneant dropship I'm building and it worked perfectly, its really hard and I didn't have to cut it in half or anything. The trial size is around 20 dollars so its not too expensive either.

 

[ArktosPendragon]

Another way to do this is to add a few coats of resin to the outside (have the weapon in one piece) for some basic strengthening, then SLOWLY add bits of expanding foam. If you do this, poke a few holes around the weapon for areas for the foam to come out.

 

[nrettenmaier]

jedistumpy had a good tutorial on the smoothcast method with his master chief helmet. I don't remember where it was and since the site changed I'm still not used to everything but it probably won't take that long to find.

The only thing I'd be careful about with the expanding foam is you have to be really careful and really watch it, otherwise it will warp your gun. This is why I think the smoothcast is a better method because it only takes about five minutes and it won't warp the gun, as long as you put a coat of resin on the outside first.

 

[Road Kill]

Just an idea to put out there that me and my friend tried was to make the gun and maybe split it somewhere over all into two pieces or even make it but leave a hole for expanding foam, my friend tried it out but he put too much in at once and it poofed the paper out. You can get the foam at Menards and maybe Home Depot....Though if you screw up you'll have to pep another rifle...Just an idea.

you can get it at Home Depot

 

[pwner50]

So you guys think the best think would be to add coats of resin to the outside then pour in smooth cast through a hole or opening? I just want to know if I can put the rifle parts together now or later.

thanks