The parts of the set-up I use:
(1) Underside of the top plate, a piece of 3/4” MDF with a 1/8” MDF frame that clamps a full size 9” x 11” sheet of 100 grit sandpaper to it. It’s upper side has knobs used as handles.
(2) The fixture bottom has an 3-1/4” opening that’s just scrap 1/8” MDF strips glued to a piece of 3/4” MDF (4).
(3) An insert that goes into the opening. It’s made of two layers of thin card with mat board “walls”.
(4) The fixture bottom has been temporarily nailed to a piece of plywood that’s been clamped (5) to a table to prevent it from sliding all around as I use it.
(6) Although I could use a vacuum cleaner to suck up all the plaster powder sanding residue, I normally use a 2-1/2” paint brush to sweep it into a bucket under the table, thus reclaiming the powder which I’ll eventually use for some future project. I’m weird that way.
Closer view of the opening with the insert. It’s been sized to loosely hold four wall pieces. The areas above and to the left of the walls greatly help to collect the sanded powder, preventing it from getting everywhere…
The process is simple: Put the top plate on, slide it around up/down, left/right, lift it off…
Take out the sanded pieces and the insert, clean everything off, store the pieces away for later use, reinstall the insert and four more raw castings, begin again. That’s it!
All in all, a nice way to while away an afternoon in a garage, especially if you’re watching The Game.
Same insert can be used for other pieces as well.
Special insert for arch pieces.