Yeah - super handy - especially for fitting the back - would not be without mine. I get my sanding discs from Axminster
Measure twice, cut once...
Machining my R4800 sanding dish. Rough cuts taken with a 9mm straight bit and then final passes with a 10mm ball nose cutter on 2mm pitch. This gave small ridges between the cuts but these were so insignificant that I didn't bother sanding them before bonding on a layer of formica to both sides with PVA. I wasn't sure it would confirm to the dish shape properly but a dry run in the vacuum press suggested that it would work fine. Not an essential step but one which will make replacing the abrasive paper much easier when it needs it.
Ok, took it out of the press and put it through the sander to trim the laminate flush. Cut up an 80g sanding belt and stuck glue film on the back before carefully applying it the the machined did. Having stuck it all around the edges I then put it in the vacuum press to pull it down evenly into the dish to avoid any change of wrinkles. I figured if Formica can do it a sheet of sand paper should work too! And there we are! An R4800 sanding dish. Clamped the ziracote sides into the Mould and discovered that the side templates may not have been as accurate as I’d hoped! But 20 minutes of sanding and a small blister later all the pencil marks had gone and it all looked good. The great thing about a spherical sanding surface is that you don’t have to worry about alignment as every part of the surface has identical geometry. Time to make the flat board to do the front edge. Easier and quicker and less sanding (10 minutes, no additional blisters) and I have one body ready to receive its soundboard.