# Adequate vacuum pump?



## IdahoMole (Aug 8, 2016)

Looking forward to the time when I will need to have a scrubber I believe I would prefer a vacuum system similar to the one employed by philddreamer. It is 4metals design if I remember correctly. I have two pumps that I salvaged from some medical equipment and I would like some opinions as to whether these will work or not or how long they may last. They are the "Wob-L" design compressor made by Thomas Ind. and they should pull 27 inches of vacuum. I don't know how many CFM they can move. The best I can determine is 2-4 CFM but that info was vague. If anyone has any experience with these pumps I like to hear about it.


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## butcher (Aug 9, 2016)

I am not sure what is inside, the chamber. The case looks like it may be aluminum, the external fittings brass.
If the internals can withstand acid (i.e. Teflon diaphragm and chamber...), the external fittings can be changed.
Sorry, I cannot help with how the pump was made or if it will hold up as I have not tore one of those apart.
Most medical vacuum pumps or air compressors were not built to handle acids.
Most medical vacuum pumps will not handle acids, they were not built for that purpose, although many of them used Teflon diaphragms, and stainless steel valves most are built out of aluminum, some of the older ones even used aluminum pistons... 

a venturi jet pump or injector can be bought fairly cheap, that and using a water pump is what I would look into.

https://en.wikipedia.org/wiki/Injector
http://www.venturipumps.com/eductor.htm


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## IdahoMole (Aug 10, 2016)

I opened it up and there is aluminum everywhere with what looks like a stainless steel reed. I am still leaning toward the vacuum scrubber. The pump was free so I'll use it until it dies and replace it with another. The vacuum pumps from harbor freight are cheap and some members here have had good luck with them. Thanks for chiming in Butcher.


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## 4metals (Aug 10, 2016)

For years all refiners used were mechanical vacuum pumps. They protected the innards by bubbling the incoming gasses which pull the fume through the pump in a bubble trap, usually one with caustic and one with water. But that only made the inevitable failure take longer to arrive.


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## philddreamer (Aug 10, 2016)

> They protected the innards by bubbling the incoming gasses which pull the fume through the pump in a bubble trap, usually one with caustic and one with water. But that only made the inevitable failure take longer to arrive.


In essence that's how I run mine. First pump lasted about 2 years; the second one going on 3.

Idaho, I received a PM from you, but I can't open it. I get a notice, "...not authorized to read the PM". :roll: 

Take care!

Phil


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## Palladium (Aug 11, 2016)

I have the first (cheap e-bay) vacuum pump i started with at the farm about 7 years ago. It's been run like a dog! All i've ever used is a mini scrubber on the gases and used motor oil in it. 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=17396&p=176864&hilit=scrubber#p176864


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## IdahoMole (Aug 12, 2016)

Phil, my PM was concerning the scrubber shown in your shed build thread. I'll post my question there.


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