Clearance holes through one perimeter frame, and tapped holes through the other, allow me to clamp the two using thumbscrews. There is a thin rubber gasket between the sheets along the inner edge of the perimeter frame. This in turn is connected, through a stopcock, with another fitting which allows attachment of a 60ml plastic syringe. It stands about 1200mm tall, is closed permanently at the bottom, and has a removable cover. Unfortunately, the pumps do not put out enough pressure to completely atomize the etchant, but the spray is fine enough for the finest etching I do.
All plumbing is vinyl tubing with plastic fittings and hose clamps.
The plastic hub of this spider presses onto the titanium shaft. It is very flat, dent and scratch free, but a little on the expensive side. I have been searching for a metals supplier who will sell small quantities of bulk material. I would like to try full-hard temper for pieces that do not require a lot of forming. I use Laminar LM dry-film photoresist from Morton International.