Vacuum Desiccator made of PVC pipe

[chy_farm]

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.

Chy

[chy_farm]

This tool is used when you want to make parts that should have elasticity like rubber, so in a case you use Room Temperature Vulcanizing (RTV) rubber silicone, or liquid polyurethane. Below is a simple example I did some years ago.

Making a mock-up with cray;


Place them in a container and pour liquid plaster to the top edge of the cray;


Take out the cray and brush off inside of the room;


If needed place the part you need. In this case I placed a couple of polyurethane bars inside, that I will take out off the place after cure, in a purpose to get a little more elasticity to this rubber part.


Now it's the right time you use this tool, Vacuum Desiccator!
Make mixture of A and B types of RTV silicone rubber, star it well.
Place the container of this mixture inside of this Vacuum Desiccator, and turn on the vacuum pump.
Keep the motor run for a minute or two, knowing a lot of foam coming off from the liquid mixture.
Kill the motor and take out the mixture, pour it into the mold;


Keep the mold still for required time, take them out with care;


Chy

[mwmkravchenko]

I have a rotary vane vacuum pump that I use for complex wood-working. I also fabricate and do R&D work for loudspeaker design. Thanks for the fruitful ideas. It makes me think.

[chy_farm]

I have a rotary vane vacuum pump that I use for complex wood-working. I also fabricate and do R&D work for loudspeaker design. Thanks for the fruitful ideas. It makes me think.

Good morning @mwmkravchenko, you seem to have a nice vacuum pump there. I too have one here, one made in France;

This one gives me a tad more bigger vacuum than the one I posted lately above.
The previous one is an oil-less pump for vacuum freeze drying, which I got basically for my another homemade-vacuum-freeze-dryer
project, but it's been on the shelf for more than five years, lol.

[DIYer]

Thanks chy_farm! We've added your Vacuum Dessicator to our Miscellaneous category,
as well as to your builder page: chy_farm's Homemade Tools. Your receipt:

Vacuum Dessicator by chy_farm

tags: vacuum