Wild Card Week -
Composites

12.05.18

Earlier in the semester when my proposed final project still included making a helmet, one of the TAs suggested that I use the composite workflow. Although I've pivoted and my final no longer requires a helmet, I still want to try it out.

I can't drape my actual helmet since the taper at bottom means it would be impossible to remove the helmet from the composite once the epoxy has hardened. Creating a form out of foam seemed like the best bet, that way, if need be I could always dissovle or burn the foam out. So the first step in making a foam form was 3D modeling. To make matters more complicated, the desktop shopbot only supports a height of about 3-4 inches, furthermore the foam we had in the shop was about 2.5 inches thick.

I found a .stl file for a helmet online and proceeded to slice it into four segments that were of equal thickness, approximately 2 inches. I later discovered that my measurements in Rhino were slightly off, so the helmet came out smaller than I imagined but perfectly proportioned nonetheless.

I milled each 2 inch section of the helmet separately and then assembled them using double sided tape, which worked quite well. Absentmindedly, I failed to get a photo of the finished foam model, which is a pity since it came out very well. Eventually, it was necessary to destroy it while extricating it from the harded composite.

Once the foam form is ready, the steps for making a composite are as follows:

1. Cover the foam with plastic wrap for easy removal
2. Mix the epoxy and hardener in a 2:1 ratio
3. Cut the material (burlap in my case) in strips whose shape will conform to the shape you're draping. I used long, skinny triangles for draping the dome of the helmet
4. Drap the form in the expoy soaked strips of fabric
5. wrap everything in the bleeder (plastic bag we perforated with the spiky roller that resembles a torture device)
6. wrap with the synthetic stuffing
7. wrap with release fabric
8. finally, vacuum seal everything and wait

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