Plaster arm cast

I’ve made gloves in the past by using my own arm as a template and it has worked well enough, but this time I’m using Terraflex and I know I’m going to be bending hot plastic over my arm and I don’t want to deal with the burns so I figured I’d make a cast of my arm! I did a little bit of research before choosing this method. The professional way to do it would have been to purchase an alginate mold material, mold both arms in a bucket, then cast them in plastic BUT I’m cheap so I went with purchasing plaster wrap (mesh permeated with plaster) and Plaster of Paris. This actually worked surprisingly well, granted I only have a left arm and don’t plan to cast the right yet.
So here’s what I did!

First I wrapped my arm in plastic wrap because I didn’t want to deal with greasing up my arm with vaseline or similar. I cut strips of the plaster wrap long enough to just go around the meatiest part of my with a little bit of overlap. (I rolled out the entire length of plaster wrap, then cut maybe twenty strips — I didn’t count). Then following the directions for the plaster wrap, began to wrap my arm, starting near my elbow, overlapping about halfway. Most of it, I only overlapped one layer, so it’s total about two layers — pretty thin — but areas like the wrist got an extra layer because even though I thought I wasn’t moving, my wrist would still bend. I made sure that I was really smoothing out the plaster when applying the strips, that way it would be “air tight.”
Once dry, I CAREFULLY cut down the center, from elbow to about the middle of my wrist until I could just get my hand out. Then I patched up the seam with smaller strips of plaster wrap and let it dry overnight.
Next I made sure there wasn’t any plastic wrap left inside and sprayed the inside of the mold with Mold Release (I don’t know if this made any difference or not…). I wrapped the outside of the mold with plastic wrap and put it in a big baggie — I didn’t know if the mold would be water-tight or not, hence the precaution. (turns out, it mostly was water tight, cool!) Then tied a string around the mold and propped it upright (hanging from my cabinet). Then I mixed the Plaster of Paris in small batches and poured it in. The divot in the upper arm is where the plaster was drying faster than I could pour it. After about an hour, I unwrapped it from the plastic/baggie/etc and cut the mold free, allowing the arm to continue to cure. Curing took DAYS! In hindsight, I should have made some sort of hollow insert. The arm is heavy and there isn’t a way to really hold it upright… live and learn, right?
Anyway, I let the arm sit in the sun, flipping it over every day until it was finally no longer moist to touch. I sanded it down with 80 grit sandpaper (do this outside..what a mess) then sprayed it with a clear coat. Done!
Now I have my own arm to work off of and so far it’s been great! It isn’t perfect but it’s good enough!

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