To the left are several of the template pieces. The leftmost is the bottom of the forearm which has already been bevelled. The middle pieces with the half circle shapes cut out are going to be the wrist plate. I thought about it and realized the hand hole would look better if it hugged my wrist relatively tight as opposed to being big enough for me to get my hand through. One side will be glued in, the other will be inserted and held in place by wooden dowels (thanks for the idea Ikea). The last piece shown is one of the sides. This piece is boring as it's just a rectangle. Rectangles aren't exciting. When painted, it will have a silver stripe down the side. That's exciting.
This is the bottom and side after the Gorilla Glue has been applied. I'm using a bunch of books leftover from college to hold them down. When this dried, there was a little bit of give as styrofoam bends a bit, but the joint held tight.
This is the near complete forearm. Inside I've glued blocks to keep the wrist plate at the proper depth when inserted. The outer wrist plate in this photo has been glued in place. When it comes time to put the costume on, all I've got to do is insert my arm through the elbow joint, place my wrist against the hole, and insert the other plate (again, which will be held in place by wooden dowels). Yes, I did a dry run without dowels. Worked like a charm. I realize everything looks a bit rough, but when it's all dry I can sand it to smooth it down and paint it.
Ever a captain of efficiency, while the forearm was drying I began work on one of the exhaust pipes. For some reason I found it retardedly hard to cut PVC pipe straight with a hacksaw. I tried twice and ended up with two pieces of equal length that have a slight angle to the bottom. Looking at this, I realized I kind of liked it so I kept them. Using a drill, I put holes in the larger pipe to match Optimus Prime's smokestacks. Using PVC glue (this stuff is NASTY), I glued the two ends together. I simply had to hold them tight for 30 seconds, and then let the pipe sit for 30 minutes. I stuffed styrofoam between the pipes to hold them together and will leave it in for extra strength. I have no doubt I could snap the smokestack in half without any effort, but so long as I don't try I believe it will hold.