When working with melted plastic in a metal pan, it's useful to have a tamper tool.
When a plastic piece is starting to melt, the tamper is used to:
- squeeze out any air bubbles that may be embedded in the plastic (necessary if you started with granules of plastic, or started with multi-layered plastic (such as plastic bags), or if you plan on folding over the plastic while working it)
- reduce the thickness of the plastic mass, which makes it much easier to ensure it's heated all the way through
To construct a crude 4" diameter tamper:
Optional: you can shape the wood piece to have a better handle (perhaps shaped something like an espresso tamper's handle).
- get a 4x4" piece of wood; cut a length of ~8" off
- buy some thin sheet metal (26gauge is good, it's available at Lowe's/Home Depot for ~$5)
- use tin-snips to cut the sheet metal so it fits the end of the 4x4 (with a little extra, so it wraps around and covers the post's sides by ~2")
(if you don't have tin snips already, buy a pair, you'll need them anyway. They're incredibly useful for cutting pieces of plastic down to size)
- hammer nails through the parts of the sheet metal that are wrapped around to the side
The metal end-cap is needed because the wood is porous, and soaks up plastic. If the metal cap wasn't there, the plastic would stick to the wood, and would cross-contaminate plastic from one project to the next.