Vacuum forming lessons

Started out with the basic mold on his vacuum box. Hooked up to a small shop vac. I tapered the sides of the balsa wood base to match the flare at the bottom of the canopy. I drilled holes in the balsa wood for additional vacuum due to that flare just to make sure the plastic pulled in there.

We’re using the kitchen oven here. Gas stove set at 350F. Firebrick on each side to support the frame.

The frame is metal picture frame style held together with aligator clips. Yep that’s me doing my best Vanna, the correct letter was T...-38A

It took 1min 20 sec for the 0.020” petg to sag and be ready to form. The first canopy was really good we thought. A little later we found it didn’t quite form completely in one corner so it will be my test fit piece and the one I use when i try to cut my first canopy out of the plastic form!

We did 3 good ones out of 0.020” petg and 2 out of 0.030” petg. The 030 petg was really really hard to get off the mold. We stopped after the 2nd one. I was worried we’d break the mold trying to get it out. We had to do a lot of cutting where the plastic pulled in around the edges and then pry it up with a stick between the plastic and the balsa wood.