# Vacuum pump question



## Hammonds (Dec 16, 2018)

I’m gonna to ask a question and many probably be shaking your head. I just put in my first piece of wood in cactus juice and the pump was turned on. WOW!!! I had vacuum!!! I had lots of foam just like in the YouTube video’s. Now, my question....my chamber holds vacuum really well. Do I run the vacuum pump the entire time or will the chamber keep pulling the the air from the wood if it just remains under vacuum and the pump turned off? With the pump off, I was still getting some bubbles coming out of the wood. Set me straight please!!!


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## Bigdrowdy1 (Dec 16, 2018)

Run continuously till the air bubbles stop.

Reactions: Like 1 | Agree 4


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## FLQuacker (Dec 16, 2018)

Control the foam up with your valve for the first few minutes..don't want it sucked into the pump.

I change the oil every 5 runs in mine.

I usually get impatient and quit when there's just few tiny bubbles remaing...but let it soak at ambient over night. Some woods take longer.

Only time I've ever had an issue was on a long vacuum (8 hrs) and it went into a heat and started solidifying! The ambient temp was not THAT high, late in the afternoon. That changed my mind on long pulls.

@rocky1

Reactions: Like 1


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## gman2431 (Dec 16, 2018)

It's also not good to shut your pump off while it's under vacuum.

Reactions: Like 1 | Agree 3


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## Hammonds (Dec 20, 2018)

Thanks for the info!


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## kweinert (Dec 20, 2018)

You can also look at this: https://www.joewoodworker.com/veneering/EVS/concept.htm

It will keep a vacuum on your chamber without the pump having to run continuously but still be there if you have any small leaks or enough air comes out of the wood to reduce the pressure too much.

I've been using one for years now (although not continuously to be fair.) It is nice to know that you can keep the juice under vacuum without having to run your pump all the time.

Reactions: Informative 2


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## kweinert (Dec 21, 2018)

Just a followup note - when I built mine the shortest 4" piece of PVC I could find was longer than was needed for two reservoir chambers so I built 4. I actually emailed him to be sure it would be OK :) Just a few extra fittings to plumb them in and I had extra 'capacity'. I haven't used mine for veneering but it's worked very well for both stabilizing and a vacuum chuck.

Reactions: Like 1


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## rocky1 (Dec 21, 2018)

If you're in a hurry, run it continuous until it stops bubbling. If you aren't in a hurry, shut it down and let it soak a few days under vacuum. Pull it down every day or two and just let it soak.

No disrespect intended, I understand everyone says you are supposed to do this with your vacuum pump, and you're supposed to do that, and you shouldn't do this or that.

- I run John Deere hydraulic oil in mine, it runs 15 - 20 degrees cooler. Have been running it for several years now... NO ill effects seen.
- I change my oil when it looks like it needs changing, or 8-10 stabilizing jobs later... NO ill effects seen.
- I shut mine down under vacuum, start it up under vacuum, frequently, always have... NO ill effects seen.

What I don't do is run the pump for eternity and heat things up. Having had mine apart and cleaned it up a time or two, I can tell you without a moment's reservation, there is nothing magic inside of it, and there is nothing inside of it that won't be damaged by heat any faster than it is damaged by hydraulic oil, or stopping and starting under vacuum.

A couple things to remember:

-- Your vacuum pump is a tool to reduce soak time to penetrate the board with resin. If you let it sit in a bucket and soak long enough, it will penetrate it; all the vacuum is doing is speeding that process. If you pull it down, let it soak under vacuum, repeat pull every day, every other day, and leave it in for a week, it doesn't hurt anything. It simply penetrates further.

-- If you're running a $500 or $1500 vacuum pump, by all means treat it nicely. If you're running a $100 vacuum pump like most of us... Use it, abuse it, throw it away, and go buy another one like you do everything else this day and age. I'm not emotionally attached to it, I don't expect it to last forever, it's run great for 4- 5 years now. When it acted up, I tore it down, cleaned it, and put it back together, and, it just keeps on going! I'm essentially looking at a cost of $20 - $25 a year in it at this point, and if it quits tomorrow, I'm not going to lose sleep over it. I'll drive to Harbor Freight, and come home with a new one, and treat it the same way.

Reactions: Like 3 | Agree 3


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