Vacuum Desiccator made of PVC pipe

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Apr 7, 2018, 08:05 PM
chy_farm

5 Attachment(s)

Vacuum Desiccator made of PVC pipe

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.
Attachment 23149

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.
Attachment 23150

Table inside must be kept flat in operation,
Attachment 23151

so you need to get a better seal to the bottom lid which is made more robust than this inner table.
Attachment 23152

Bottom lid originally has screw around the outer edge, cut out them off so that it fits instantly to the upper housing.
Attachment 23153
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
Apr 7, 2018, 08:47 PM
chy_farm

6 Attachment(s)

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;
Attachment 23154

Place them in a container and pour liquid plaster to the top edge of the cray;
Attachment 23155

Take out the cray and brush off inside of the room;
Attachment 23156

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.
Attachment 23157

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;
Attachment 23158

Keep the mold still for required time, take them out with care;
Attachment 23159

Chy
Apr 9, 2018, 10:28 AM
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.
Apr 9, 2018, 06:34 PM
chy_farm

1 Attachment(s)

Quote:

Originally Posted by 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.

Good morning @mwmkravchenko, you seem to have a nice vacuum pump there. I too have one here, one made in France;
Attachment 23177
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.
Apr 10, 2018, 07:53 AM
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:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-vacuum-dessicator"> <img src="/uploads/212661/homemade-vacuum-dessicator.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-vacuum-dessicator">Vacuum Dessicator</a> <span> by <a href="http://www.homemadetools.net/builder/chy_farm">chy_farm</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/vacuum'>vacuum</a> </div> </div> </div> </div>