UNI over the bottle has created a permanent memorial to dumb ideas. Then I dropped it and broke the bottle, so binned the sad remains.
Decided to progress the idea of making foam plugs using a lathe so back to the other shed. I hot glued together some blue wing foam scraps to make blanks. I measured the cans I will use at 66mm diameter, so made 12mm ply discs 70mm in diameter. Roughed them out with a jigsaw, then turned them to size on the lathe.
Put a scrap of blue wing foam into a container of petrol to see if it was efficient at removing it.
I hot glued the discs to the foam blanks, instantly regretting it, because nails through the discs into the foam would have worked just as well.
Turned the foam plugs down to match the ply discs, using chisels and sanding blocks. Was astounded by how good they look.
Turned one of the discs down to 56mm, attached to each foam block with nails, and rounded the ends to match the cans using the chisel and sandpaper. Again astounded at lovely result. Covered up the foam with duct tape.
Petrol test has reduced the block of foam to a blue slurry at the bottom of the container. Remind me to not get avgas inside my wings.