- Pipe clamp (size appropriate for coaster or trivet)
- Place your clamp onto a firm surface.
- Fill inside clamp with corks standing upright. They need to be the same height, but can be different shapes or turned upside down to fit more snug.
- Once the corks are firmly fitted inside the clamp, slide the clamp halfway up sides.
- Tighten clamp with screwdriver so no corks can drop out.
- Polyurethane & leave to dry.