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View Full Version : Vacuum Chuck? Used Gast vs A/C unit conversion



Jed Malcore
10-20-2016, 9:00 AM
I am looking at getting a vacuum chuck set up would you suggest going with the Gast pump or converting an old AC unit... I have access to an AC but need some instructions on how to convert the pump (So if you have those or know where I could find them, that would be helpful to)... Thanks for the help!

David Gilbert
10-20-2016, 5:39 PM
Since I know little to nothing regarding air conditioning systems, I would say that you should go with the Gast. Using something that is designed to do exactly what you want usually makes good sense. Search the model number on the internet and you can buy rebuilding kits for about $45. I thought my Gast was ailing so I bought a kit. Then the pump started to work fine so now I have a kit and a pump that works.

Cheers,
David

Tom Albrecht
10-20-2016, 9:45 PM
I found a new Gast on Ebay very reasonable. If you are nit in a hurry you will find a good deal.

Alan Heffernan
10-20-2016, 9:51 PM
I just went through the exercise of putting a vacuum chuck system together and Gast is the way to go. The Gast will tolerate some leakage and an AC compressor will not move enough air to handle leaks.

As Tom mentioned, you can get a used Gast via Ebay and other outlets. They are built like tanks and can be rebuilt easily if need be.

Steve Mawson
10-21-2016, 9:46 AM
A diaphragm pump will work very well also and is not as expensive when bought new as the Gast. Not sure about used Gast prices.

Alan Heffernan
10-22-2016, 9:39 AM
Yes a diaphragm pump will work and can be a bit quieter.

I chose the rotary vane pump because it pulls a deeper vacuum than a diaphragm pump can deliver. A Gast rotary vane in good shape will pull greater than 26" Hg. Mine with new carbon vanes pushes 27". They also have a good flow rate as well to tolerate some leakage.

A good target for a used Gast is $200 or less in hand via ebay. Many will be 220 volt which is seems silly for a 1/4 hp motor but they are typically surplus from laboratory equipment. They are robust little pumps and can be easily rebuilt but the kit to do so is roughly $70. A rebuild kit should restore it to new condition. So yes, they can be pricey.

John King
10-22-2016, 11:59 AM
Please advise source of rebuild kits for Gast pumps. - John

Steve Mawson
10-22-2016, 2:49 PM
Not sure where you are at but I have got parts from these folks. Skarda Equipment Company, Inc.
2563 Farnam
Omaha, NE 68131
P: 800-228-9750
P: 402-422-0430

They were very helpful as well.

Alan Heffernan
10-22-2016, 3:22 PM
Please advise source of rebuild kits for Gast pumps. - John
John,
If you don't already know, confirm your pump model number and the kit you need via Gast . They have great customer service and answer the phone! You can likely find it on the Gast website as well. I called them to confirm the kit number I needed.

Then with the kit number in hand, a few options:
http://www.wholesalesepticsupply.com/
http://www.gptooling.com/gast-repair-kits.html
search eBay

I paid $69 shipping included for the kit I needed for my Gast 0523 pump.

Josh Bowman
10-22-2016, 4:50 PM
I bought a gast pump off of ebay, worked well, but like you wanted to know if I could get parts. Called Gast, they told me I could buy from them or Granger. They asked for the ser. # on the pump and even told me that it came off of a 1962 printer from France. So mine has traveled the world. Anyway the point is, I had a good experience with them. From my years of using a pump, here's my opinon. You need to be able to hold about 17"Hg vacuum. And the more cubic feet per minute (CFM), the better. I've often opened a worm hole while turning and was thankful to the extra CFM. I also have a holdfast vacuum system. I like it ok and it's quite......until the air compressor starts, but it doesn't have nearly the CFM of the old Gast.