You’ll want to read our page on building a simple vacuum form table first.
- 30 medium binder clips
- 4 large binder clips
The most commonly used materials to vacuform are thermoplastics called ABS or Styrene. Thermoplastics are plastics that change properties when heated. They each have slightly different properties, so you’ll want to do some research to figure out if you want one over the other.
Just remember that the thicker the plastic, the harder it will be to successfully vacuform with our weak vacuum. The thinner the plastic, the more fragile the item.
We just went with what was available in our area at the thickness we wanted which turned out to be ABS. It was a very scientific decision making process as you can see…
Cut your ABS or Styrene into squares that match the outside edge of your frame. Our frame from edge to edge is 17″ so we had a bunch of 17″ inch ABS squares cut. Once your square is cut, binder clip the ABS to the frame at two inch intervals all along the outside edge. More clips is better than fewer so have at it.
Set up your vacuuform table within a couple of feet of your oven. You only have a few seconds to work, so you don’t want to take more than a couple of steps. Attach your vacuum nozzle to the hole in the side of the table. If necessary, duct tape it in place.
Remove both oven racks from your oven. Cover one of the racks with tinfoil and put it in the bottom slot. This helps the oven heat evenly and is there in case you accidentally completely melt your ABS. You’ll probably want to turn on your oven fans as well and make sure the room is well ventilated as melting plastic fumes are probably not going to do you any good.
Pre-heat your oven. Check Do-It-Yourself Vacuum Forming for a handy dandy chart that lists temperatures and times for each type of plastic and thickness. It doesn’t take much to do this, in either temperature or time, so make sure to check.
Set your frame with the ABS on your table, and put the oven rack on top of it. Take your large binder clips and clip through the bars of the oven rack onto your frame. The book has this very complicated frame mechanism you can build but… this was easier.
Once your oven is heated up, put the rack/frame combo into the top rack position in your oven and shut the oven door.
Each thickness and type requires a different cooking time, in our case, 15 minutes. As the plastic softens, it begins to droop. We noticed our plastic, at 15 minutes, drooped about six inches below the frame. We then marked the oven door, so we could consistently melt the plastic to the same point each time.
About one minute before your plastic done, turn on your vacuum and check to make sure the table is set up correctly. Whatever item you’re vacuforming should be in the middle of the table.
Once the plastic is melted sufficiently, using oven mitts, grasp the frame and with a swift tug, pull it from the binder clips. Then, immediately place it down on your table, over whatever object you are vacuforming, making sure to press the frame into the weatherstripping to complete the vacuum. The plastic gets sucked down within seconds and cools.
Once the plastic has cooled, you can take off the binder clips lift up your hardened piece of plastic.
Trim away the excess plastic and you’re done! (And if you’re wondering what those half pie-shells are, they’re the 2 halves that make up the base of our Easterling helmets.)
As always, you can email us with questions.