Help me with a vacuum press purchase

[Raymond Fries]

I posted in classifieds looking for a used vacuum press. I am starting out making veneer boxes and planning on flatwork at this time. Maybe I will get to some curved surfaces on the boxes after I get going. I would still like to plan for expansion should I broaden my horizons but trying to keep my budget close to 4 or 5 hundred. I know nothing about the systems and looking for some advise to purchase what fits my needs while trying to stay within my target budget.

This looked like a nice started system: http://www.vacupress.com/products2.htm#compact100


I realize that a larger CFM rating will pull down faster and allow for a larger bag. Is there any other reason why I would need a CFM larger than 1? Do I really need a poly bag for flat work?

What would you advise me to purchase to get started. I am not opposed to building a kit from Joe Woodworker but I get a little lost trying to figure out what is best for me.

Thanks for any tips or direction.

[Mike Henderson]

Poly is better than vinyl for curved surfaces. The major reason for a higher CFM bag is to pull down faster. This is primarily a need in larger bags and for curved work.

If you buy a small system, and take care of it, you might be able to sell it and get a fair amount of your money back. A buyer is going to be concerned about whether there are any leaks in the bag, and how much life is left in the pump.

Regarding a kit from Joe Woodworker, he used to sell a kit, without a pump, for about $150. I don't know what the current price is. He also sold some rebuilt pumps for about $100. To that you add some schedule 40 PVC which is not very expensive. While this won't help you now, Joe has a sale on bags about once a year. But without a sale, I guess a 4' by 8' bag will cost you about $200. I haven't checked prices in a long time.

Mike

[John Lanciani]

This pump from veneer supplies; http://www.veneersupplies.com/products/Excel-1-Continuous-Run-Vacuum-Press-System.html plus a bag of your choice from the same site will get you going fast and easy and keep you on your budget. I've been using this same pump for flatwork with a 2' x 4' bag for several years and it's done everything I've wanted to do with zero issues. The small pumps like this do have their limitations, such as large or leaky bags or deeply curved work.

[Loren Woirhaye]

I bought a used Gast pump on ebay for less that $100 shipped. It looks just like the one referenced above and it works fine.

[Matt Day]

Sign up for jww's email list. He sends out sale emails monthly and I think he has his bags on sale every few months or a couple times a year. He usually makes the sale worth the wait for the bags.

I have one of his systems that I use with my compressor and it works great. Fun build too.

[Raymond Fries]

Looks like Joe does have a nice 3 CFM rebuilt pump for $100. Will probably go with that one. Do I need the auto cycling kit? Does it really matter if the pump runs continuously? What is your recommecdation?

[Mike Henderson]

Looks like Joe does have a nice 3 CFM rebuilt pump for $100. Will probably go with that one. Do I need the auto cycling kit? Does it really matter if the pump runs continuously? What is your recommendation?
If you're going to work in the shop while you have something in press, you'll appreciate the intermittent pump. The pump is loud enough that it could drive you out of the shop. I have the intermittent pump and I can put up with it running every now and again (and on a good bag, the pump doesn't run very often).

Mike

[George Gyulatyan]

Also, if you already have a compressor, the Venturi based systems make sense as you don't have to purchase a pump. Check Joe's site for a chart with CFM ratings and compressor requirements.

[Mike Henderson]

George is right about the venturi systems. However, you trade off running a vacuum pump for running your compressor. I haven't used a venturi system but I think the venturi has to run continuously to keep up the vacuum (I don't think it has a way of detecting the level of vacuum and turning off when a certain level of vacuum is reached). If so, your compressor is going to run a lot unless you have a big compressor and tank.

Mike

[Jim Barstow]

I got an excel 1 from veneersupplies.com. My first project was to make some bent lamination panels for a sleigh bed. (Not "veneered" because the surface layer was 1/8" thick.) I looked
at the vacupress.com sight and their kits seem just as expensive as the ones I looked at. (Veneersuppliers.com seems to be associated with joewoodworker.com.) I bought the bag separately
and opted for the more expensive one that I thought would last longer. I've been more than happy with the system.

[Frank Drew]

This is some years ago, but I bought a used, high quality vacuum pump from a used machinery dealer for maybe $75, and some new but not expensive sheet vinyl and vinyl glue to make my own bags (easy peasy). Tubing was scrap, the platen was a piece of particle board that I scored on the table saw, etc. I was up and running for a very minimal investment in either time or money, and got great results right from the get go.

I can't say enough good about vacuum veneering: even if you buy everything new, the ease of the process and the terrific results still make it worth your investment

[Metod Alif]

About two months ago I assembled Joewoodworker's EVS kit.I am very pleased with the system as well as with Joe's help. I had few questions (my ignorance) during the assembly, and Joe Joe helped promptly and effectively. I also find his web site very instructive.
Best wishes,
Metod

[Rob Feldner]

In the shop that I'm at we have a venturi system hooked up to a 60" x 120" table. The compressor does cycle a couple of times as the system clamps down and the venturi only cycles for short periods to maintain the vaccuum. Bear in mind, I'm talking about a large compressor that is piped throughout the shop. Your best bet would be to figure out how large of a bag or table you'll need at first and talk to the suppliers of the pumps and other equipment to find something that suits you needs.

[fred marcuson]

to evacuate a large table , get a portable air tank (the type used to inflate tires etc) .
hook it inline to your vacuum pump . empty the tank , then open valve to to empty table .
i had mine hooked up with a bypass valve(s) . open tank , vacuum table , then close tank and just use the pump .
used to make wind chests for pipe organs , some were pretty big . pretty sure the table i used was 5 x 9 .

[Loren Woirhaye]

My small Gast pump is probably not much CFM but it's also not noisy and I just let it run. I've done some curved stuff with it in a 4x4 bag and it worked fine.

[Mike Henderson]

This is some years ago, but I bought a used, high quality vacuum pump from a used machinery dealer for maybe $75, and some new but not expensive sheet vinyl and vinyl glue to make my own bags (easy peasy). Tubing was scrap, the platen was a piece of particle board that I scored on the table saw, etc. I was up and running for a very minimal investment in either time or money, and got great results right from the get go.

I can't say enough good about vacuum veneering: even if you buy everything new, the ease of the process and the terrific results still make it worth your investment
I tried making my own bags but ran into problems.

1. If you have any leaks, they can be difficult to find. Let me change that to very difficult.

2. The recommended technique for sealing the edges is to glue the vinyl together, then fold the edges over and glue the fold. This means your edges are much thicker than the rest of the bag. Because of this gluing technique, you can't use a C-clamp (this is a special vacuum bag C-clamp, not a metal C-clamp) to seal the bag. Other techniques can be used to seal the bag after putting your work in, but they are not as convenient as the C-clamp and are generally heavy because you have to use regular clamps to hold the sealing mechanism together. Commercial bags are heat bonded and are the same thickness as the rest of the bag (actually, a bit thinner).

After using a home made bag for a while, I finally broke down and bought a commercial bag. It was much easier to use.

Mike

[william watts]

I got a used Thomas pump and a rebuild kit for it on E-bay, very easy to install the new parts, reed valves and seals. The pump motor draws 3.9 amps so I think its 1/3 hp. I used a vacuum/pressure gauge from the auto dept at Sears. I ordered a thru the bag vacuum fitting from a company called Bond Line and use some air hose I already had. Then Mounted everything in open top plywood box.

The bag I made from 5 mil plastic sheeting sealed with clear packing tape, the bag was about 2ft. x3ft. made to size for veneered boxes. The bags would last for 3-4 uses and then to many small leaks developed so I would just make another bag. Then my wife suggested those blanket / pillow storage bags that compress down with a vacuum cleaner these work very well and are easy to seal. You can get these at Bed Bath and Beyond 4 bags for 30.00 just install the thru the bag vacuum fitting and do not use the vacuum cleaner fitting. I have many uses on only one bag and no leaks, or maybe the pump's powerful enough to to overcome any leaks, the pump pulls 24 in. of hg. and sucks the bag down very fast.

This set up works well for flat work, for curved work you need a better bag. Total cost was less than 150.00

[Raymond Fries]

Thanks for all of the tips everyone. I think I am going to start out simple and upgrade later if necessary. Going with the rebuilt pump and the CRS kit. I can always add the EVS kit later. I have not decided on a bag yet to purchase yet but I think I would rather purchase one and go from there. I will most likely start with a vinyl since I am planning on flatwork at this time. I emailed Joe and he said he was planning on a sale early in November so I guess I will wait a week or so and see what he has to offer.

[Bruce Wrenn]

Check with local HVAC dealers. When vac pumps no longer pull in the micro range, they become trash. Most are rated at 3-6 CFM, You will need a filter on inlet to prevent glue from getting into pump. Metal shelled fuel filter works great, as does HF's moisture filter.

[Mike Henderson]

Check with local HVAC dealers. When vac pumps no longer pull in the micro range, they become trash. Most are rated at 3-6 CFM, You will need a filter on inlet to prevent glue from getting into pump. Metal shelled fuel filter works great, as does HF's moisture filter.
Most of the vacuum pumps for A/C systems (that I was familiar with) have a fairly low CFM. They will pull a very fine vacuum but they don't move a lot of air.

They don't need to move a lot of air, either. When you're evacuating a system, you hook the vacuum pump to the system and let it run for a fair amount of time so that you're sure that any moisture in the system is removed.

Mike

[Keith Hankins]

I know I'm coming late to this, but I can help. I went though this a few years back. I was lucky to have bought a gast pump at a company auction for 50 cents (I know I suck). I built the kit from Joe-woodworker and have been using it flawlessly for several years now. My advise would be to get a pump that has continuous use duty cycle. Now, truly if you have Joe's kit that senses vacuum drop and will cycle the the pump on/off, that is truly not the case, but I think its better to have one that could handle it. Thats just my opinion.

I'll also give you some advice on bags. I've got two diff types vinyl & polyurethane and polly is worlds apart better! I bought my bags from Joe. After all the help he gave me during my build, I felt it was only right to give him my business. My first project was a veneered bubinga top for a wine cabinet. I bought a vinyl 4x4 bag due to cost and I'd had the cost of building the press. It was ok, kinda stiff and had to be really worked to get over the platen and the mesh inserted and sealed and on the pump.

Took a little time which concerned me because I was afraid if I had any gaps or air pockets the glue would tac prior to getting under vacuum. It turned out great for a first try. My second project was laminated bed rails for an 8 sided pencil post bed. Due to their length (Cal King bed), I went with the polly bag. The bag was a 2x9 and not cheap, but I have to say I will not get any other type of bag again. It's super plyable and stays that way. It makes it super easy to get the platten in, and the project and mesh cover and sealed up quick. Love it! For my platen material I buy 3/4" vynl coverd chip board. Works great and pretty cheap. Be sure to round your edges with a router so they don't damage your bag!

For sharp corners on the piece itself, I place pieces of cardboard over the mesh on all sharp corners so you don't get a sharp point anywhere on your bag. One final thing you can put a grid of grooves on your platen to keep air pockets from forming, but I chose to spring for the mesh from Joe, and Have been very satisfied with it. I've only had one bad press of all I've done, but that was my mistake for not rolling out my glue properly and created a bubble. I sliced it with a razor, shot some glue in, put it back and it was fixed.

One final word. If you plan in the future to do bent lamination with it over a form, fet the right pump up front. Do some reading on Joe's site and send him a note. While my little gast works fantastic, it was from a lab and not designed to pull the full bar that would be needed to pull wood over a form. The larger ones will. So when I start that type of project, I'll have to upgrade. Have fun and enjoy!

Vinyl bag http://flic.kr/p/evugxg

Poly bag http://flic.kr/p/cBfFYd

[Raymond Fries]

Keith - Thanks for sharing. Based on your experience I think I will get a poly bag to start out. I just need to decide on which size. Did you go with the 20 or 30 mil bag?

Does anyone have thoughts on if the Thomas 3.15 CFM will pull down on curved surfaces?

[Mike Henderson]

Keith - Thanks for sharing. Based on your experience I think I will get a poly bag to start out. I just need to decide on which size. Did you go with the 20 or 30 mil bag?

Does anyone have thoughts on if the Thomas 3.15 CFM will pull down on curved surfaces?
The problem with curved work is that the work holds the bag "apart" which means there's a lot of air in the bag that has to be evacuated before the bag pulls down on the work. You can mitigate that problem in a couple of ways.

1. Use your hands and collapse the bag to the best of your ability. Every bit of air you can force out is air the pump doesn't have to take out.

2. Make a fitting for your vacuum cleaner (shop vac) and hook that up first - before you hook your vacuum pump up. That will evacuate the air quickly (note: shop vacs don't pull a strong vac so that's why you can't use them for pressing). Then switch to your vacuum pump.

Once you get the air out, you don't need a lot of CFM to do the pressing.

But IMHO, a 3+ CFM should work for you, even with curved work. Run a test with dry work to see how long it takes to pull down. That'll tell you whether you need to use one of the suggestions above. Most people don't do a lot of curved work so don't spend a lot of money for it unless you really need it.

Mike

[Keith Hankins]

Here is the response from Joe on the subject of form pressing

"The vacuum press can put down 1,750 lbs of pressure per square foot. That is the case for any pump that can draw 25" of Hg. The formula is approximately 70 lbs per square foot of pressure for each inch of Hg. For instance, the pumps I offer all create 25" of Hg. Thus... 70 x 25 = 1750
Whether or not that is enough to make the curve you need is something you'll find out once you try it. It depends on the orientation of the grain, the wood species, the number of plies, and the thickness of the plies. I have a lot of customers doing this type of work and I suspect they have no problems putting a curve on it.

Joe"

As to the bag I got the duramax elite 2x9 20mil. http://www.veneersupplies.com/products/Dura-Max-Elite-Polyurethane-Vacuum-Bag-2-x-9.html

His price has not changed since I bought it 148$. It seems high, but when I considered the cost as part of the project then did not really matter. I keep it properly cared for (in a box rolled not folded sealed from light). Also important is to use the right glue for the right purpose. I use veneer glue for the thin vaneers and used the utlta-cat PPR glue for the lamination project which required protective gear (mask) during mixing. Talk to Joe he's great for any questions and will only give you the right suggestion not the one that necessarily makes him the most money. I like that quality! Here's my project good luck with yours!

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