Vacuum pump for Veneer press.

[C Scott McDonald]

I want to start doing veneer work for things like humidors with curved tops etc. So I thought a vacuum veneer press would be really helpful. Looking at Joe Woodworkers plans he lists several that can work. Does anybody have any suggestions on which one to buy? I know they are spendy but I want to buy a new one so I dont have to search the world over for a used one. Are there trusted brands in the vacuum pump industry? I know nothing of the vacuum pump world.

[Mike King]

I made a venturi from a kit from Joe Woodworker. Worked like a champ! And I didn't have to buy a vacuum press but was able to use my compressor.

Mike

[Steven Hosler]

I also made the venturi vacuum from Joe Woodworker. I up-ed the size of the reserve tanks a little, but it works great. If you have a compressor already, why by a vacuum pump.

[John Seybold]

Hi, Scott,

I bought an earlier model of the Excel 5 vacuum press from veneersupplies.com (see here), which is the same guy (Joe) of joewoodworker.com. It's a kit, but you can put it together in a few minutes. I've used it many times now on a variety of veneering projects (and also for laminating my own plywood, making bent laminated forms, etc) and it's great. Robust and reliable and develops a strong vacuum.

You'll also need a vacuum bag. For my first, I made my own out of a sheet of vinyl and a piece of hose:
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It's easy to do - fold the vinyl over on itself, trapping the hose in the fold, and use a bunch of vinyl glue to seal up the sides, making an envelope. The platen is just a scrap of 24"x18" melamine coated particleboard with a couple of holes drilled in it to accept the hose and direct the suction to the top surface, and some table saw cuts to allow air to escape. Vinyl adheres to itself so well that usually I can just pinch it closed and the vacuum will keep it sealed, but occasionally I have to clamp a couple of pieces of wood across the open end to keep it closed. If you have a good pump, a few small leaks in the bag don't matter. This is good enough for small panels, box tops, marquetry pieces, etc, and I still use it all the time. I think the materials cost me about $10, and it may be all you need. I also have a full size polyurethane bag that I use for larger or oddly shaped pieces, but that's more of an investment.

Good luck! For veneer work, nothing beats a vacuum press.

[Steve Demuth]

If you already have an air compressor, then I would recommend the venturi-based kit that Joe sells. You can reliably get 25" Hg vacuum with the venturi, which is more than adequate for veneer pressing, and the venturi itself has no moving parts, so isn't going to be a maintenance issue the way a pump can.

The keys to trouble free vacuum press veneer work, in my experience, are the bag, your cauls/forms, and your glue technique. Even a very indifferent vacuum will generate enough pressure and a tight glue-up if you have a good bag, the right forms, and the right amount of the right glue. I've done it with a shop-vac, e.g. - you only get about 15" Hg vaccuum but even that is 7 psi even distributed across the veneer, which is sufficient. I don't recommend the shop vac approach, but as I say, the other elements are by far the most important things to get right.

[David Kumm]

Thomas pumps can be found for a decent price on ebay or C, especially if you have 240 volt as they are less desirable than the 110 ones. DaveDSC04251.jpgDSC04251.jpg

[Bill Adamsen]

Built one from Joe's plans. Didn't think about buying a 240 volt pump - clever - that would have been a good way to save.

While I have a large compressor, I turn it off overnight or when I'm not in the shop just in case there is an issue. When veneering I like being able to leave the pump on overnight, especially for aliphatic glues whose cure time is impacted by the vacuum. I feel comfortable leaving the pump on overnight.

[Mike Henderson]

I made a couple of vacuum pumps, one which used the smaller pump from Joe Woodworker (the reconditioned one). Works like a champ and sucks down fast enough.

Mike

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[Bruce Wrenn]

If you go the venturi route, research Air-Vac Engineering's AH-93. It's the standard around which many commercial systems are built. I use both venturi and discarded HVAC pumps, along with a home made vac pump made using an automotive AC compressor.

[Chris Fairbanks]

If you already have an air compressor, then I would recommend the venturi-based kit that Joe sells. You can reliably get 25" Hg vacuum with the venturi, which is more than adequate for veneer pressing, and the venturi itself has no moving parts, so isn't going to be a maintenance issue the way a pump can.

The keys to trouble free vacuum press veneer work, in my experience, are the bag, your cauls/forms, and your glue technique. Even a very indifferent vacuum will generate enough pressure and a tight glue-up if you have a good bag, the right forms, and the right amount of the right glue. I've done it with a shop-vac, e.g. - you only get about 15" Hg vaccuum but even that is 7 psi even distributed across the veneer, which is sufficient. I don't recommend the shop vac approach, but as I say, the other elements are by far the most important things to get right.

The main concern I have with the venturi setups is compressed air is one of the most expensive means of potential energy. For something like a nail gun its negligible but for use in a sander or a vacuum setup you will be running a big 3HP+ motor which adds up to a large electricity bill (especially if you are using it for longer duration, plus a compressor is noisy as hell vs a pump. For light use its great but if you plan to use it more than that bite the bullet and buy a pump.