Will this vacuum set up work for Cactus Juice?

Signed-In Members Don't See This Ad
jbswearingen

jbswearingen

Member
Joined
Dec 10, 2008
Messages
752
Location
Bowie, MD
Here's the equipment I'm using--

A Pyrex bell jar and Duoseal 1400 pump from the 60's. Automotive vacuum hose (which surprisingly doesn't collapse).

I see that 24" Hg is optimal...but if I'm reading this gauge properly I'm seeing ~6.75" Hg (171mm Hg). Is that correct?

I hooked it all up, stuffed the internal (salsa) jar with blanks and filled with Curtis' CJ. I turned the pump on and after about 35 seconds, it reached its max vacuum of 171mm Hg. There was a lot of foaming initially, but it stopped quickly--within a few minutes. The tall piece of wood was flipped after the first vacuum pull and and redone.

Is this gauge I have reading incorrectly?

20130401_114545_zps9b228298.jpg


20130401_114552_zpsb604eafe.jpg


20130401_114558_zpsfa017de8.jpg


20130401_114613_zpsc59b925f.jpg
 
Signed-In Members Don't See This Ad
According to my math, you are pulling 23.031" Hg. The inner dial is NOT inHg. It is displaying altitude x 1,000. You are showing 36,000' above sea level. This is NOT a common measure of vacuum by any means but mmHg is and converts to the 23.031" Hg shown above.

Not sure where you read that 24" is ideal as that is NOT the case unless you are at high elevation. Ideal is a high as you can get! According to wikipedia, Bowie, MD is 154' above sea level. On a standard atmospheric day, your maximum theoretical vacuum is 29.7512" Hg at your elevation. You should be able to easily pull 29" with the right pump. I doubt that pump is capable, though. If you are on a budget and want a pump that will pull closer to that on the cheap, look into building one from an old refrigerator compressor. Basically get a hold of a refrigerator compressor and wire it so you can plug it in. There will be two copper lines coming out of it. Turn it on and figure out which one suck and which one blows. Use compression fittings to make the connection to your vacuum hose and you are good to go.
 
Thanks, Curtis. I appreciate you clearing it up. I'm not *too* constrained budgets wise; I think I'll order one of those HF vacuum pumps the folks here recommend. This pump was given to me before being tossed in the trash. If it doesn't work, no big deal.
 
And to directly answer your question...your setup will work but will not get the best results possible. The idea behind vacuum impregnation is to get as much air out of the blanks as possible. A perfect vacuum is the absence of all air. At the level of vacuum you are pulling, you are removing a maximum of 77.4% of the air. You should be able to get 99% vacuum.
 
There are a lot of folks using the HF pumps but there are much better pumps out there for similar money. The complaint I hear ALL the time about the HF pumps is the amount of oil mist they put into the air. I have had customers call saying they have a blue fog in their shop from the oil mist! Personally, I would look on E-bay and try to find a good JB Industries pump. It is American made and the one I am running does not create any mist. They will run $250 used, though. If you want to keep it comparable to the HF pumps, look at some of the Robinair. They are still Asian imports but the company behind them is much more reputable. I have a Robinair 15310 as a backup/show/demo pump and it does a good job and was a little over $100 shipped from Amazon. com. Don't get hung up on CFMs on your pump. A 3 CFM pump will do just as good of a job, just as quickly as a higher CFM pump. Here is a video I did recently comparing the time it takes to get to full vacuum between my 6 CFM JB and the 3 CFM Robinair. (BTW, there was no difference in time)

[yt]qZKmy_kdi_o[/yt]
 
Last edited:
Oh yeah, I know that for these small chambers, even .5cfm will work fine. I'm just finally getting off my butt and figuring out a system because I ordered a quart of your juice and I want to use it before it goes bad! With my slow rate of completing things six months is NOT a long shelf life.

;)
 
Too bad though as I like the look of that gauge being different and that it's ex-NASA. If you sold that gauge alone on Ebay and played up the 1960s NASA angle, it might actually pay for a new pump.
 
Or heck, sell the old pump underneath. New, they run north of $2k. A couple hundred for it would make me happy!
 
Before I got rid of it and bought a new one, I would attach a good, new gauge directly to the pump and see what it is capable of. The gauge could be off or out of calibration. That and change the oil and make sure it is at the correct level. That would tell you if it is the pump or if you are getting leaks elsewhere. That pump should be capable of better than you are getting.
 
Ah. Okay. I'll check that out. Thanks, Curtis.

Healey--

If it's a bum gauge, you can have it for the cost of shipping.
 
Curtis--

I finally bought a proper pump for the job. I found a JB Industries Platinum series DV-85N 3 CFM for under $250 shipped. Today I'm heading over to Grainger to pick up oil for it. Can you advise on how to connect it to my bell jar? It has a pair of intakes that are threaded with an o-ring to seal. Where do I find the connector for it and what tubing do you recommend? I notice you're using some type of clear tubing; how well does it stand up to the vacuum?

Thanks for your help!




healey--

I haven't gotten around to testing the old gauge yet.
 
Healey--

The bad news is that it works. The good news is that I'm gonna keep it. Sorry man!

I figured out I can just put my hose directly over the intake and screw clamp it down. It draws down to a nearly perfect vacuum (according to the gauge), but when I add on the bell jar, it can't get "above" 32k feet. I'm getting some out gassing on the stock, but not enough.

I think the problem is that the jar uses a thick "vacuum" grease to seal, and that there isn't enough there. I'll get some more from work and lay it on thicker to test. If that works, then I'll pull it apart, scrub it clean, and hunt down a rubber gasket to seal it--breaking the seal when it's coated with grease is a real bear!
 
Try any BORG Brad. I worked with Curtis on both my pumps, a refer and HF. I use clear tubing on a brass fitting running to the pump. Using a tank From Curtis, it cost $4 to adapt the refridge pump and saved me $2 for the HF pump. Really easy and fun to do...from a guy who burns water!
 
You must log in or register to reply here.
Back
Top Bottom