vacuum pump question

[darrin1200]

I am entering the casting and stabilizing world. I have my pressure pot set up, now I'm looking for a vacuum pump. I have two used ones that I am considering for purchase this weekend.

A JB Fast Vac 5cfm. Model dv-142n. About an hour drive away. $100.
Yellow Jacket 7cfm. Only used twice. Not as far a drive. $300.

I know that either of these will do the job of stabilizing, but l also want to start using a vacuum chuck on my lathe. Is the newer 7 cfm worth the extra money or is it overkill.

Any input is welcome.

 

[lorbay]

The 5 cfm is just fine, its not all about the cfm when it comes to what we do with them.

Lin.

 

[darrin1200]

The 5 cfm is just fine, its not all about the cfm when it comes to what we do with them.

Lin.

I know the cfm isn't important for stabilizing, but what about when it comes to holding a piece of wood on the lathe.

 

[MesquiteMan]

Higher CFM will allow for more leakage when vacuum chucking IF you use a big enough hose. The problem, however, is that many try to use a 1/4" hose for their vacuum chuck and a hose of that size only allows around 1 CFM to pass through it.

JB makes a great pump as does Yellow Jacket. Both are American made quality. The JB model you mention, I believe, is an older model that is no longer made. Not an issue as JB parts are typically easy to get, even on older pumps.

Personally, if I was going to spend $300, I would buy a new JB Eliminator instead of the Yellow Jacket. Don't get me wrong, Yellow Jacket makes great pumps but they are overpriced IMO, at least for what we are doing.

 

[NittanyLion]

The JB pump is twice the pump as the yellow jacket. At that price, it's a bargain. We rebuild our JB pumps, some of them 20 years old...used heavily; a yellow jacket is pretty much a throw away if there is a problem. The price on the yellow jacket is too high as well. You can buy a new one for that price. Hope this helps.

 

[cal91666]

Amazon has the Yellow Jacket 93600 7CFM for
$283.64 + $20.29 shipping

 

[darrin1200]

I have made the deal for the JB pump. It turns out that rather than me driving the two hours to pick it up, the guy is going to get one of his suppliers to bring down to Brockville for me.

Thanks everyone. I will let you know how the setup goes.

 

[steve worcester]

That will be fine for both applications, assuming it can get to a high enough suction for the vacuum in stabilizing. Even then, a decent working pump has good resale value.
In looking at the pumps, they say they will pull 15 Microns, but I only understand InHg, so maybe Curtis can chime in. I would consider him the resident expert in this field.

 

[MesquiteMan]

Since it is a JB, is will certainly get good enough vacuum for stabilizing! JB pumps are my favorite since they are 100% USA made and are professional quality pumps that will pull a 25 micron vacuum, much more than you will ever be able to get in a vacuum chamber.