Tuesday 31 January 2012

Reinforcement


I've got a nice thin coat of resin throughout the entire inside shell. Good and tacky for the next part of the procedure. The reinforcement. Something to give it a bit more rigidity.

If it was just the paper, it'd be just floppy. And if it was just the resin coating, it would be brittle. It'd crack and things would break off, it'd be a mess. You need something to bind it all together. Like all composite materials like carbon fibre and fiberglass, the process usually includes some sort of fabric for the resin to permeate into and bond. The fabric would give it both strength and flexibility.


The Fabric:
 This fabric is from the fabric store. Just a simple sheer material at $7 for a square yard. Plenty for this project. Just pick something with strength, has plenty of holes, and thin enough that can bend over small shapes.


Obstacle! It's a minor one. I fitted the helmet over my head and noticed the neck opening is a tad tight. Not like I was claustrophobic or anything. Just wanted a bit more room. So, with a pair of scissors, just trimmed it off a bit. 

TIP: At this stage, the paper and thin layer of resin was still easy to cut through. This is really the only time to make these adjustments. After I put the fabric in, scissors won't cut it. Only a dremel too would work then. So, plan accordingly!


Pre-cut the fabric into small manageable pieces. Make enough for one good batch of resin. Actually, make MORE than you need. It would be difficult to stop in the middle of the resin process just to cut more fabric.



The Resin Process:

System Three is a resin that was rated for indoor application. Most are super toxic that MUST be used outdoors or with great ventilation. The fumes are really REALLY bad for you. Like cancer bad. Don't risk it. Just not worth it.

Prepare the area. I used a large sheet of cardboard. WEAR DISPOSABLE GLOVES! Stuff is sticky. And won't wash out with simple soap and water.


1) Thoroughly mix the resin and hardener in a plastic (disposable) cup. (2 part resin + 1 part hardener) Try to limit the bubbles when stirring.
2) With the brush, layer a thin coat of resin on the area you are going to apply. About the size of the fabric you have.
3) Lay on fabric
4) Lay on another thin coat of resin over the fabric. Making sure it's thoroughly soaked. Especially all the edges.

TIP: Don't mix too much resin at a time. Only mix enough to work on for a half and hour. If you lay too much fabric at one time, it might get heavy and start to sag. Better to work one layer at a time. And in one area. Too much resin.. would just pool down.. making a huge mess. And possibly sticking your work onto the cardboard! Ruining everything. (Trust me, I speak from experience here!) You'd be better off spreading the work across a few days. Working in small sections at a time.

TIP: Keep a towel nearby. Wipe stray drops the moment it lands.

TIP: Don't OVER soak. Too little resin, the fabric would come off and you'll lose strength. Too much resin, and it'll become brittle and crack.. and you'll lose strength. Find and learn that balance.


Overlap each piece a little. This would give it the strength and flexibility. Try not to go past the edges. It'll be more work for you later if you do. And that would involve a dremel tool. 

Hang it up to dry. Make sure the shape is correct. Not skewed to one side. At this point I have no idea if it's the correct width. I may need to make adjustments later.



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