Vacuum Laminating - Whaat type/brand pump?

I've been vacuum laminating shop-sawn veneers for six years using a Robin Air 15300, 3 cfm pump which lasted 5 years, pulled 29" Hg and was very fast on a small bag. I did not change oil after every use as recommended and condensation in the oil finally killed it. A very good pump, I thought. I then replaced with an upgraded model 15500 5 cfm Robin Air and this pump failed in just two weeks. I got a quick replacement on warranty and this replacement started blowing smoke and lost vacuum in only 4 hours use. Ten days later, the mfgr. has yet to answer my warranty claim. The last two pumps had an issue of blowing out vaporized oil smoke; the first one didn't. Further, out of 463 reviews at Amazon, 95% are highly favorable. Robin Air is a product of Bosch Tool.

This leaves me with a dilemma. Do I consider my two pump failures as just a matter of very bad luck and not likely to happen again and order another one? This type of rotary vane pump is the lowest priced type but they do have smoking problems AND they all (MasterCool, etc,) seem to be made by same mfgr in China. Diaphragm pumps, (Gast) which do not smoke, cost 4-5 times as much and are much lower volume. To pull 6 cfm at 29 hg. i'd pay close to $1,000, much more than I can bear. There are lots of other options in teh 1-2 cfm range. At 5 cfm my pump pulled a full vacuum in just one minute, and since thers is no auto-cycle, I have to manually fire it up 3-4 times to maintain a vacuum for one hour, the time it takes my glue to set up in my operation using hard 1/8" veneers (the less porous the wood, the longer the set up time). My need for fast draw, high pressure, low cost suggests I should take another chance with Robin Air.

Try veneersupplies.com Joe has two oilless 5 cfm vacuum pumps for between $240 and $330 and smaller ones for less. He also sells a very reasonable priced auto cycling kit. There are TONS of these used by woodworkers.

Edit: I should note none of his pumps will pull 29 inches of mercury but I haven't had any issues and never heard anyone else express issues with 24-26" Hg

Check the offerings from Joe Woodworker --http://www.veneersupplies.com/categories/Vacuum__Press__Items/Vacuum__Press__Parts/
They're currently offering two 5 CFM pumps for about $300. They are oil-less rocking piston pumps.

I was able to source a surplus Gast pump when I put together my vacuum system a number of years ago.

You don't need an oil based pump for veneer, and you don't need to pull 29" Hg. Almost any good vacuum pump will do the job and will pull 24 to 25" Hg, which is plenty. Some will pull more.

If you're using a small bag, you don't even need a 5 CFM. A smaller pump will maintain the vacuum. The only thing a big pump does for you is get the work under press quickly. If you were doing big bags, maybe 4' by 8', a 5 CFM might be justified. Even on those, you can hook your shop vac on and pull most of the air out before you connect your vacuum pump.

Mike

CFM requirement is driven by leakage more than bag size IMHO.

I've used a air compressor venturi type to remove most of the air and get it into a vacuum and maintain it with a repurposed refrigeration compressor, just add a shot of oil to the intake before each use. That takes a couple of valves and fittings, but very doable. Not necessary to spend lots of money to do a basicly simple task.

Quote:

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Originally Posted by Ken Combs

I've used a air compressor venturi type to remove most of the air and get it into a vacuum

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All of my vacuum pressing and veneering has always been done with a venturi type vacuum pump. Never an issue.

Look up a rebuild kit for your original pump. It's a complete pak that you install. Takes longer to order than to install, well almost. You will need new gaskets to go with pump pak.

Attachment 351392 Thomas 2750 ( I think ) pump off ebay. I'm remembering about $200. Dave

David,

A couple of people have mentioned Joe Woodworker/VeneerSupplies - he has a lot of info on his web site about vacuum pressing for veneer, etc. Here is a page on the ins and outs of vacuum pumps:
http://www.joewoodworker.com/veneeri...acuumpress.htm

And a bit about the process: http://www.joewoodworker.com/veneeri...ng-started.htm

You can also talk to Joe on the phone. He spent 1/2 hour answering all my questions. Sounds like a nice guy and gives all information freely.

His EVS plans include a vacuum reservoir and pressure switch to automatically cycle only when needed, which may not be much unless you have a leak. I like his MAC valve which lets the pump start freewheeling for less stress. A LOT of people have built these for vacuum pressing, clamping, and vacuum chucking on the lathe - you can see user pictures on his web site. I bought one of his pumps and all the parts for the kit and plan to build it "any day now."

Quote:

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Originally Posted by David Pascoe

I've been vacuum laminating shop-sawn veneers for six years using a Robin Air 15300, 3 cfm pump which lasted 5 years, pulled 29" Hg and was very fast on a small bag. I did not change oil after every use as recommended and condensation in the oil finally killed it. A very good pump, I thought. I then replaced with an upgraded model 15500 5 cfm Robin Air and this pump failed in just two weeks. I got a quick replacement on warranty and this replacement started blowing smoke and lost vacuum in only 4 hours use. Ten days later, the mfgr. has yet to answer my warranty claim. The last two pumps had an issue of blowing out vaporized oil smoke; the first one didn't. Further, out of 463 reviews at Amazon, 95% are highly favorable. Robin Air is a product of Bosch Tool.

This leaves me with a dilemma. Do I consider my two pump failures as just a matter of very bad luck and not likely to happen again and order another one? This type of rotary vane pump is the lowest priced type but they do have smoking problems AND they all (MasterCool, etc,) seem to be made by same mfgr in China. Diaphragm pumps, (Gast) which do not smoke, cost 4-5 times as much and are much lower volume. To pull 6 cfm at 29 hg. i'd pay close to $1,000, much more than I can bear. There are lots of other options in teh 1-2 cfm range. At 5 cfm my pump pulled a full vacuum in just one minute, and since thers is no auto-cycle, I have to manually fire it up 3-4 times to maintain a vacuum for one hour, the time it takes my glue to set up in my operation using hard 1/8" veneers (the less porous the wood, the longer the set up time). My need for fast draw, high pressure, low cost suggests I should take another chance with Robin Air.

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Joe really is a nice guy...anyone into veneer really needs to be on his mailing list, too.

Quote:

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Originally Posted by Van Huskey

Try veneersupplies.com Joe has two oilless 5 cfm vacuum pumps for between $240 and $330 and smaller ones for less. He also sells a very reasonable priced auto cycling kit. There are TONS of these used by woodworkers.

Edit: I should note none of his pumps will pull 29 inches of mercury but I haven't had any issues and never heard anyone else express issues with 24-26" Hg

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I'm looking to buy get into vacuum bagging, and was looking at the Excel 5 from vennersupplies.com. I am looking to make a snowboard. I live at about 4,700 feet above sea level. The Excel 5 pump will draw about 20-21" of Hg at my elevation. Could anyone tell me if that is enough to press a snowboard?

I am also looking at the Robinair 15500 pump. My main concern with the Robinair is the oil mist that some say it spits. Does anyone have any experience with that pump?

Thanks.

For snowboards / skateboards, I have seen setups where people use a firehose, with air pressure rather than a vacuum.

Here's one I found a while back:
http://www.happymonkeysnowboards.com...s_Construction