I needed a vacuum desiccator, that I use for defoaming e.g. liquid silicone rubber or liquid polyurethane prior to casting them into the molds.
A vacuum desiccator is ; https://www.thomassci.com/scientific...um-Desiccators
The motor sitting in the right is a vacuum pump, grey cylinder in the left is the one I made.
Joints are of plastic plumber material, note use specific vacuum hose or it won't do the job.
Clear top cover is a 5mm thick acrylic plate. I am sure this thickness is not sufficient, better recommend you some more thicker ones like 10mm thick. Glue this plate on top with silicone rubber.
Table inside must be kept flat in operation,
so you need to get a better seal to the bottom lid which is made more robust than this inner table.
Bottom lid originally has screw around the outer edge, cut out them off so that it fits instantly to the upper housing.
As far the bottom seal, I recommend you to chose a soft RTV rubber silicone for some casting mold use.
First wrap the bottom edge with a wide tape to make a good round room for the seal you are going to make, pour mixed liquid RTV silicone to this room and keep it still for the required time.