Vacuum Veneering - Oil or Oilless Pump?

[glenn bradley]

Just as the title says. Does anyone have trouble with the oil discharge from a oil based vacuum pump in a woodworking shop?

[ChrisA Edwards]

I use a cheap oil vacuum pump as the vacuum source for my vacuum adapter on my lathe.

It does spit a fine mist of oil out of the exhaust and there are filter/exhausts that can be added to minimize this vapor, re-condense and return the oil, but I just place a loose towel over the port and this seems to capture and condense the mist.

If you are concerned about the mist settling on and around your shop or workpiece, you can always extend the tube from you vacuum bagging area to the pump and maybe locate the pump where it's more suitable.

[Mike Henderson]

I've always used an oilless pump. Some of the oil pumps are designed for air conditioning work. They will pull a very deep vacuum but they're somewhat slow. And you don't need a really hard vacuum for veneer work.

Mike

[Bill Dufour]

How often do you use the pump. I would use a longer hose and put it outside when needed.
Bil lD

[John K Jordan]

Just as the title says. Does anyone have trouble with the oil discharge from a oil based vacuum pump in a woodworking shop?

Some notes by "Joe Woodworker" on vacuum pumps, perhaps useful. (I bought a piston pump and components from him to build his EVS design.)

https://www.joewoodworker.com/veneering/EVS/vacuum-pumps.htm

[Jamie Buxton]

My first vacuum press had an oil pump which I got nearly for free. It was a mess. I built a filter for the outlet, but it was still annoying. I replaced it pretty quickly.

[glenn bradley]

This is all good stuff. Thanks to all so far. I was a little put off by the combination of Joe not selling oil pumps and talking them down; no offense intended to Joe. The comments here and elsewhere help me see that the reason he doesn't offer them is that they are not well suited.

I have seen a lot of pros that veneer a lot that do not bother with a controller. Rather they let the vacuum just run for 30 minutes to an hour for the glue to set and move on. Having never vacuum veneered, I am gathering all the info I can. I will be getting a vacuum pump for an HVAC install and wanted to optimize my spending by getting a good vac pump and just using it for the install as well. Maybe this is a good time for a $50 Chinese pump for the one job and wait on the veneering pump?

Thoughts from the collective?

[Tom M King]

I would loan you one, if you weren't on the opposite side of the country.

[Bruce Wrenn]

HVAC pumps can run for HOURS! It often takes 24 hours or more to vacuum down large systems. Most important thing is to install a filter between bag and vacuum pump.

[Wes Grass]

Last place I worked, doing composites, we had 3 or 4 of the 5 CFM JWW pumps. I couldn't begin to estimate how many hours we had on them. We'd typically hold vacuum on layups overnight. Weekends they'd plug them into a timer to shut off after 12 hours or so.

They set them up with manifolds and valves to run multiple bags if needed.
Never once had a problem with any of them. And they're surprisingly quiet.

Yes, I have one at home too. The only thing I wish they had was a built in switch.

3/8" tubing would evacuate a bag noticeably faster than 1/4", BTW.

They had an oil pump when I started there. It always blew a little oil out. A lot more if the bag had a leak.

[glenn bradley]

I would loan you one, if you weren't on the opposite side of the country.

You’re a good man Tom. Thanks for the offer.

[George Makra]

With oil based pumps you need to change the oil frequently. This is because the oil gets contaminated with water vapor and dirt.also vacuum pump oil is pretty expensive.

You do need to need to go into a deep vacuum with veneering.

The purchase cost is similar so why not go with the oiless which is no muss or fuss.

[Justin Meyer]

If you are concerned about the mist settling on and around your shop or workpiece, you can always extend the tube from you vacuum bagging area to the pump and maybe locate the pump where it's more suitable.

If at all possible plumbing/ connection wise, it would be much better to run a tube from the pump's exhaust port to outside your shop than to extend the upstream volume/ distance. The only negative this way is the pump noise is still inside the shop. Also, even for small pumps a drip pan at the exhaust hose exit may be desirable.

[Jim Becker]

I picked up a surplus Gast pump for this application many years ago. It was "brand new", never used, but a pennies on the dollar surplus. I think it had a GE label slapped on it, but I don't recall at this point. I've never had to do any kind of maintenance on it.

[glenn bradley]

I picked up a surplus Gast pump for this application many years ago. It was "brand new", never used, but a pennies on the dollar surplus. I think it had a GE label slapped on it, but I don't recall at this point. I've never had to do any kind of maintenance on it.

Jim, how is your oil consumption and oil discharge at the exhaust please?

[Jim Becker]

Jim, how is your oil consumption and oil discharge at the exhaust please?
I have no clue if there's any oil at all...I've had the pump for at least a decade and a half. It was originally purchased for use at my lathe for using a vacuum chuck and I also have used it for veneering. More recently, I was trying it for some small, dedicated fixtures on the CNC. I'll actually have to crawl on the floor and look at it to see if there's anything related to oil. :) :D

[Mike Henderson]

Jim, how is your oil consumption and oil discharge at the exhaust please?

All the Gast pumps I've ever seen were oilless. But could be that they make a oiled pump.

Mike

[glenn bradley]

Thanks Mike and Jim!

[roger wiegand]

I can't imagine why one would mess with oil for either veneering or vacuum chuck applications. You don't need a high vacuum and oilless pumps work just fine. I've lived with literally hundreds of oil pumps for mass spectrometers and lyophilizers for many decades, they were all a pain in the patoot. For these low vac applications the oilless ones work perfectly at a fraction of the cost and maintenance, no contaminated oil to dispose of at exorbitant expense, without spewing oil mist all over the place.

[glenn bradley]

Great input Roger and all. This is what I was looking for. Oilless it is.

[Bruce Wrenn]

Got an air compressor in the shop? If so, go over to Air Vac Engineering's web site and look at a venturi. They make some that use less than a cubic foot of air per minute, and pull all the vacuum you will need. Any air compressor (oil, oil less, or diaphram) that has a threaded inlet can be converted to be a vacuum pump. Even the AC compressor from a car. My first air compressor was built from a Borg Warner AC compressor. It had "Ford style" inlets which meant I could back seat the valve and us it as a vacuum pump for AC work.

[Carroll Courtney]

Not having all kinds of experience with vacuum pumps other than one I use which is for HVAC I don't see problem either way. Either pump has no way that I can see to induce oil into bag. But again I don't have lot experience other than what works for me

[ChrisA Edwards]

I don't think there's an issue with stuff getting down to the work piece. Inline filters are used to stop foreign material/objects coming from the workpiece into the pump.

So far, my experience with a $50 oil pump, I get about 3 drops of oil, condensed on my exhaust rag, after after an hour of running.

Now the negative, if I didn't have that rag, draped over the pump exhaust, that mist would float around my shop and settle on surfaces.

[Warren Lake]

dont see how oil could get to the bag if you are sucking air not pushing. Last time i used the vacuum bag I rebuilt some huge speakers. My pump has oil and an open filter never had a rag over it. Speakers were done in Automotive finish, there was zero pollution.