Homemade Vacuum Pump

[Sam's Workshop Diary]

I build this vacuum pump out of an old fridge compressor.
I want to use it to stabilize wood with oil or resin.

[Toolmaker51]

Count me interested. Will multiple compressors pull down larger chamber through a manifold?. I have a huge bell jar approximately 24" x 30"... would double as power for a vacuum chuck.

[tonyfoale]

Some years ago I used a Fridge compressor as a vacumn pump. I used it to suck air out of epoxy and polyester resin as well shock absorber oil.
Then I picked up a real vacumn pump for almost free at a flea market so the Fridge based one just sits on a shelf now but it worked fine when I used it.
Some people do the opposite and use them as compressors.

[Toolmaker51]

Some years ago I used a Fridge compressor as a vacumn pump. I used it to suck air out of epoxy and polyester resin as well shock absorber oil.
Then I picked up a real vacumn pump for almost free at a flea market so the Fridge based one just sits on a shelf now but it worked fine when I used it.
Some people do the opposite and use them as compressors.

I got a big kick out of the spot-painter and his very mechanical adaptation, especially the former tire as air reservoir.
Yessir; vacuum that is my intention. I'm thinking a manifold with ball/ spring check valves would allow multiple pumps to pull down large bell jar without pulling on other pumps. Project is impregnating hardwood spacers and pistol grips.

[Sam's Workshop Diary]

Count me interested. Will multiple compressors pull down larger chamber through a manifold?. I have a huge bell jar approximately 24" x 30"... would double as power for a vacuum chuck.

I think it's possible to use more pumps for a better vacuum, when you have a large chamber.

[tonyfoale]

I think it's possible to use more pumps for a better vacuum, when you have a large chamber.

More pumps in parallel will not create a better vacumn but they will create the same vacumn quicker and so will have an advantage when sucking down a large container.
If you have good good compressed air supply you can buy or make a venturi vacumn pump which can provide a surprisingly good suck.

[suther51]

I do not know the max vacuum but I have used automotive a.c. pumps to create vacuum. Lots of them in junk yards.
Eric

[tonyfoale]

I do not know the max vacuum but I have used automotive a.c. pumps to create vacuum. Lots of them in junk yards.
Eric

Another option from cars is the vacumn pump used for power brakes on Diesel engined vehicles. These are actually designed as a vacumn pump to replace the intake vacumn that you get with petrol engines. Of course neither of these options have the advantage of the fridge compressor that it is all built in as a single unit, no need for an external motor.

[Toolmaker51]

More pumps in parallel will not create a better vacumn but they will create the same vacumn quicker and so will have an advantage when sucking down a large container.
If you have good good compressed air supply you can buy or make a venturi vacumn pump which can provide a surprisingly good suck.

Hmmm, running a vacuum port [eductor] hadn't occurred to me. The multiple pumps address volume in what seem economical fashion....Thinking now to pull it down with venturi [a little harder to control], and maintain it with a pump.
Until I finish the lid [bell jar] and jar hoisting sling, the seal is a question mark. Initial plan positioned it open end up, too high to reach down into, and quite heavy. bought lab grade bell at auction long ago, about 14mm wall. Definitely not the thin terrarium or display variety. Now, closed end up, vessels seat on an easy flat surface.
Per the usual, design process [skilled cobble-up] just as fun a real build. BTW, lab bells this size are ~$750, displays ~$50...crackerbox thin. So, extra care is rewarding. The sling is [might be] a stretched bicycle inner tube, three long webbing legs, terminated with a ring.

[old_toolmaker]

Sam's Workshop Diary,

Nice idea and re-use of an old compressor!
Several years ago I used an old vacuum pump and home built vacuum chuck for machining acrylic sheet parts on a small CNC mill. Worked great for me.