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:

  1. 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)
  2. 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).

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.

Pre-made tampers: