Autoleveller

Fair enough. I thought it was Isopropyl Alcohol he was using but maybe it was Acetone.

While we're on the subject of hold-down methods, Art showed me this vid before: https://youtu.be/3uTsQ3dYRrk
I was a bit sceptical about just how well the piece would be adhered but just saw this: https://youtu.be/ub6PsY4cgwg

No clamps, no double sided tape and looks incredibly strong.

With regards the second video, I use the same method to fixture stock on my milling machine to cut metal. Works a treat and holds very well. Last time I used it was to hold aluminum sheet to a 'spoil' board and was cutting out shapes using a .125 inch diameter end mill. Cleanup is not to bad as the tape peels right off and any glue residue is removed using acetone.

I have seen some serious machining done on a mill and it works.