Step 5: Make it STRONG - Outside

Picture of Make it STRONG - Outside
Wow! has it really been several days of cutting, folding, and glueing!?  All done? No left over parts?

Cool! So now you have a Halo ODST helmet made out of paper. If done right, your paper model should be strong enough for you to put it on for a test fitting. If your cuts were precise, your folds sharp and your glueing is clean then you should have a very good looking bucket.

But, it's still just paper. we need to make it stronger.

This is a two part process and there are several ways to do things. I will describe the different common methods I have tried.

The first step is to strengthen and seal/waterproof the outside. This is done by applying a thin coat of glue or resin on the outside. We want a THIN, even coat. Too much and you could loose the fine details of the pepakura or colapse the model.

The three most common ways to do this is:
1. Brush on polyester resin.
2. Brush on epoxy resin
3. Brush on wood glue.

Why three methods? Well, it really depends on two factors, your working environment and your budget. 

1. Polyester resin is cheap. a quart cost $12 at Wal***t. Problem is polyester resin puts out lots of deadly fumes. You have to wear a respirator mask and you will stink up the surrounding area. Not great if you live in an apartment. Also not good if the people around you (small children, pregnant spouse, elderly) have to stay away from dangerous chemicals.

2. Epoxy resin. General use fiberglassing EPOXY works great. It has very low odor (smells mildly like popcorn), not as toxic, and is strong. Biggest issue is that it is expensive. A quart will run about $25.

3. Wood Glue is also cheap and is available everywhere. It is non-toxic. Has no odor. Requires no mixing of chemicals. You just brush it on and let it dry. Only issue with it is that it is not as strong. Also, becuase it is water based, too much of it may warp your helmet. Once dry, it is waterproof. This is the method I used for the the helmet in this example.

** Note: I have used all three methods above.  There is a fourth method called AquaResin. Never tried it. ***
If you coat the card in a layer of petroleum jelly, leave overnight and wipe off, you have waterproof card you could coat with PVA glue/woodworker's glue and the card won't absorb any of the water. When I first started on my helmet two years ago, I assembled it with undiluted PVA glue instead of nitrocellulose glue and it warped. Nitrocellulose isn't the best solution either, when I applied too much, it would bead on the outside of the helmet and leave a hard residue that can't be removed until detailing. But it dries faster than PVA glue so I went with that.

I found that rubber cement worked the best for this. Glue every tab, leave dry, then press together. It's not permanent but it can be repositioned until you glue it together with PVA glue.

Hope this helps!
MrTinkerer (author)  ThePyroManiac3 years ago
I like the rubber cement idea.
I'm glad this helps.

According to the bottle, if you let dry and press together, it's a temporary bond, but if you used it like regular glue and pressed tabs together while wet it's a permanent bond.

Also: excess glue and residue can be erased off the card with a regular eraser.
tbonds3 years ago
If you use the wood glue and let it dry, will it still warp if you put another coat on?
MrTinkerer (author)  tbonds3 years ago
Pdub924 years ago
hey dude! If you use fiberglass resin, how long will it take for the fumes to go away? its just that I have a dog, and I don't want him becoming fatally ill. I'm in a different part of my yard fenced away, but AI know the fumes can go anywhere. Should I just keep fido inside while I fiberglass?

MrTinkerer (author)  Pdub924 years ago
a couple of hours
Can you resin/glue it in several stages? This would surely stop it from warping or collapsing, so is it just to save time that people do it all in one go?
MrTinkerer (author)  Shadow Of Intent4 years ago
many resin in stages. it all depends on how rigid the pep is. Some pieces I resin in stages (torso), some I resin all at once (shoulders). It is also about preference and comfort level when working with resins.
Ahh okay... I meant more along the lines of doing each piece in several stages: For example, resining the visor, allowing to dry, resining the upper helmet, allowing to dry, then the mouth guard, etc.

It seems that would reduce the weight on it, and as most of it would still be dry while the other has resin on, that it would not bow under its own weight.

Best ODST helmet I've seen by the way =D
MrTinkerer (author)  Shadow Of Intent4 years ago
thanks. Yeah thats what I meant. For the helmet I resined all at once since the paper form was very regid already. The torso I had to resin in sections - i turned it upside down and resined the shoulder first, waited several hours then resined the rest of it. I did the torso that way because the paper was very floppy when the pep was done. but some parts of the armor are very rigid after the pep is complete and can take a lot of weight.
IdealL4 years ago
Here's a little info on AquaResin. It is only available online for around $60 for a 2.2 pound liquid and a 4.4 pound solid but, it's very strong. It has no odor. The only thing to mix is a non-toxic powder and a non-toxic liquid.The only issue is that you need to know is that it is water based so adding thin layers the first few times is a must. The helmet becomes waterproof once dry.