Step 5: Make it STRONG - Outside
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. ***