Vacuum pump?

[Lasse Hilbrandt]

I'm thinking about making a vacuum set-up to infuse wood. Vacuum pumps are expensive so I was wondering if there is a way to convert compressed air from my compressor to vacuum ?

[Jerry Bruette]

A venturi type vacuum generator uses compressed air to create vacuum, but you'll need a compressor with a high CFM rating that can run continuously. I'm not sure if you'll get the level of vacuum you'll need for infusion.

We use venturi type generators at work but it's usually for lifting and placing parts.

[Lasse Hilbrandt]

I'm not sure the venturi effect can create sufficient vacuum.

[John K Jordan]

I'm not sure the venturi effect can create sufficient vacuum.

Venturi vacuum generators are sold specifically for vacuum infusion. A friend of mine, John Tarpley, recently did a turning club demo on infusion. He uses a venturi device and operated it with a portable air compressor, at least for the demo. The venturi generator he used was incredibly quiet - I had always imagined them to be noisy.

I believe John said a large compressor was not needed since once the air is pumped out of the infusion chamber the valve is closed to hold the pressure. This is unlike a venturi used to drive a vacuum chuck on the lathe, a vacuum press, or clamp.

If you want more details, knowing John I suspect he would be happy to share his experience and recommendations with you.
Here is a bit about him and I see it has his email address: https://www.morewoodturningmagazine.com/writer_profile.php?writerid=26

John is a soft spoken, friendly, intelligent, and creative person.

JKJ

[Lasse Hilbrandt]

Hi John.

The link does´nt work, can you repost it ?

[Brad Shipton]

I have a venturi pump from Vaccon (https://www.vaccon.com/standard-products/variable-vacuum-pumps-vdf-series) for vacuum pods. McMaster Carr re-sells these as well. My air generator consumes up to 3cfm of air, so you will need a good sized air compressor. I can generate up to 25" - 29" Hg vacuum. It is quiet at lower settings, but if I open it up it is noisy because I am basically exhausting air at 3cfm out a relatively small port. If you know how fast you want to evacuate the air and what vacuum level you need you might want to call them. They were very helpful in guiding me to the correct unit for my application.

Joe has an article too: https://www.joewoodworker.com/veneering/vacuum-infusing-chamber.htm

[John K Jordan]

Hi John.

The link does´nt work, can you repost it ?

I just tested it by clicking in the message and it works here. If I repost it would be the same link. If it still doesn't work you should be able to find the page with a google search for john tarpley woodturner and click on the link for More Woodturning Magazine.

JKJ

[Lasse Hilbrandt]

Thankyou all

[Bruce Wrenn]

Go over to Air-Vac-Store.com, and look at their AVR series of venturi pumps. Most consume less than 2.0 CF of air per minute. The AVR 093 is used in a lot of commercial vacuum presses. If the inlet to your compressor has threads, it can be used as a vacuum pump. Be sure to add a filter to inlet line. Google "vacuum generators" for others.

[Doug Walls]

If the inlet to your compressor has threads, it can be used as a vacuum pump. I have an oil-less compressor that has threaded inlets & outlets, I reversed the air lines & it worked great as a vacuum pump.

Try doing a YouTube search for "converting a air compressor into a vacuum pump".
There's also some good information on making a vacuum pump on joewoodworker.com

Doug

[Marvin Hasenak]

I have used the venturi pump that Harbor Freight sells, currently on sale for $18. According to my vacuum gauge it will not pull the full amount, while the small vacuum pump they sell does. I have no real reason to spend the $150 for the real thing, so I keep using my $38 version, that sold for $12 when I bought it years ago. I use it for my dye projects. It will cost you to get hose end connections to hook it up to a compressor, I think that set me back another $20.

[Lasse Hilbrandt]

Is it very noisy with that vacuum pump? I will try to find something similar in Europe :)

[Doug Walls]

Is it very noisy with that vacuum pump? The one I used is a dual cylinder (oil-less design) which is fairly noisy as a compressor or a vacuum pump. The slower speed oil lucubrated compressor pumps are usually a lot quieter.

I haven't gotten around to fully assembling my vacuum pump set-up yet since I need several more parts & fittings for it to operate/cycle automatically. But here's a few pictures of it just using ice-maker fittings to temporarily test it out. My plans are to use brass fittings & copper tubing for the plumbing & also add a electric solenoid valve/controller to allow the system cycle on & off as needed.

Doug

[Robbie Buckley]

Would a water aspirator work? They are pretty cheap and can pull down to about 0.1 atm.
http://www.iecpl.com.au/z_pdfs/ch1852+1853-001.pdf

[Bill Dufour]

An old compressor from a refrigerator or ac unit can be used as a vacuum pump. will exhaust oil and need to be refilled with oil but for short term use it is supposed to be okay.
Bill

[Larry Edgerton]

Hospitals are a good source for vacuum pumps, it where I got mine.

[Bill Adamsen]

On my suggestion, a buddy added a larger (30 gallon) surplus tank to his vacuum to reduce the cycling. It works great. I cautioned that the vacuum in the tank might make vacuum pump startup difficult (my system has a bleed tank/valve to avoid that issue). I have been told it is not an issue. I bring it up because I'd assume a vacuum tank would be a natural addition to a venturi system to keep the compressor from running?

[John K Jordan]

On my suggestion, a buddy added a larger (30 gallon) surplus tank to his vacuum to reduce the cycling. It works great. I cautioned that the vacuum in the tank might make vacuum pump startup difficult (my system has a bleed tank/valve to avoid that issue). I have been told it is not an issue. I bring it up because I'd assume a vacuum tank would be a natural addition to a venturi system to keep the compressor from running?

The OP wanted a vacuum pump for infusion. I mentioned this before, but again: local turner John Tarpley brought his infusion system to the club for a demo and used a venturi generator. He said that compressor does not need to run continuously. It runs until it pull the proper vacuum on the infusion chamber then the valve is closed to hold the vacuum and the pump is turned off. The infusion time can be significant but the vacuum is not needed the whole time.

JKJ

[Bill Adamsen]

Yes, went back to the original post and he did say "to infuse wood." I'm not familiar with those systems (probably should be) but have seen the pots and suspect they leak very little. If one already has a compressor, a venturi is likely a very simple and inexpensive way to generate the vacuum needed.

When I see the words infuse or infusion I always think vacuum film on a boat hull to infuse a composite with resin, and in my experience, unlike vacuum bags, those are miserably difficult to stop the vacuum leaking.

[Halgeir Wold]

Lasse - this pump sells i Norway for NOK 600.... https://www.jula.no/catalog/verktoy-og-maskiner/trykkluft/kompressorer-og-vakuumpumper/vakuumpumper/vakuumpumpe-739003/?gclid=EAIaIQobChMI1PbLmtCs1gIV8wrTCh3CuQUmEAAYAiA AEgKkOvD_BwE
you should be able to find this in Denmark,too. I'va also seen pumps intended for evacuation heat pumps that were quite cheap...

[Marvin Hasenak]

If you have the patience and time, a brake bleeder vacuum pump will do the job. I think the one I have cost $15 a few years ago, it is hand operated, I had a gauge, never did get it to 100% or close but it worked for a dye experiment I wanted to try. Use the smallest container that will work, sucking out the air with a hand pump gives a new meaning to suck.

I used glass jars, I had lids with connections set up for pint, quart and gallon sized jars. The glass is safe, it won't explode. If you could reduce the air enough it could implode on itself, but it never happened to me. With a hand pump, I don't think that would ever happen. I tried using new paint cans, they worked, but I needed to see what was happening so I knew when to stop the vacuum. I could also watch what amount of the dye was being infused into the wood. Use Ball canning jars, not the recycled old mayo jars, the Ball are stronger.

[Lasse Hilbrandt]

Lasse - this pump sells i Norway for NOK 600.... https://www.jula.no/catalog/verktoy-og-maskiner/trykkluft/kompressorer-og-vakuumpumper/vakuumpumper/vakuumpumpe-739003/?gclid=EAIaIQobChMI1PbLmtCs1gIV8wrTCh3CuQUmEAAYAiA AEgKkOvD_BwE
you should be able to find this in Denmark,too. I'va also seen pumps intended for evacuation heat pumps that were quite cheap...

I see the product is out of production. I can find a similar product in Denmark but at the original price :-(

[Brandon Conover]

I use this one.
https://www.infinitytools.com/venturi-vacuum-system?gclid=EAIaIQobChMIhqCZhJnx1gIVBEGGCh3Ntw-SEAQYDCABEgI4yfD_BwE
i use it it for my Festool vac clamp instead of the Festool pump but I hear it works well for your use too. I do have a large air compressor though.