Tom King Posted May 23, 2018 Report Share Posted May 23, 2018 I'm often told that bad things come in threes. As it so happens, I have three air conditioning systems to work on-my Wife's car, my truck, and a tractor, with the tractor being too big for me to take anywhere (weighs 17,000 pounds), and really expensive to get it moved anywhere. Checking prices, I've decided to buy the equipment to do it myself. In looking at vacuum pumps, I've narrowed it down to this one (not big on HF anything). Question here is, will this also work for veneering. Biggest problem I see is adaptors from odd fittings that aren't compatible. https://www.nationaltoolwarehouse.com/VacuMaster-Vacuum-Pump-5-CFM-P34034.aspx?gclid=CjwKCAjw_47YBRBxEiwAYuKdwwU5McZCqfm7WSn_axNrS2ITcCVbFTYJ_pII5oJsBCbDZPUtLZhdwBoCglIQAvD_BwE I'll probably also be getting this gauge, so I would be able to stop it before pulling the bag apart. http://www.robinair.com/products/digital-micron-vacuum-gauge If you know offhand how much of a vacuum does vacuum bagging veneer call for, an answer would be appreciated? If you don't know right off, don't worry about it. I can look it up. Quote Link to comment Share on other sites More sharing options...
wdwerker Posted May 23, 2018 Report Share Posted May 23, 2018 That's a pretty strong pump. Mine is a single stage rotary vane pump w a 1/4 hp motor and I have used it on a 4' x 12' bag. You shouldn't have any problem adapting to a vacuum hose. Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 23, 2018 Author Report Share Posted May 23, 2018 I have a friend with all the other tools, and a reclaimer. His vacuum pump burned up beyond hope of fixing. He's the only person I loan tools to, and I let him use my mechanic shop too. He's a retired helicopter mechanic. I don't mind loaning him anything, as he always brings anything back better than it left here, always brings it back quickly, and helps me occasionally with various mechanic issues. Since I don't have to buy any of the other stuff, I figured I'd get a good pump, at least. Quote Link to comment Share on other sites More sharing options...
wdwerker Posted May 23, 2018 Report Share Posted May 23, 2018 Aircraft mechanics have to follow such exacting procedures & have their work inspected so I can see them being meticulous with the care of tools. Robinair & Gast are 2 of the better vacuum pumps. Quote Link to comment Share on other sites More sharing options...
Ronn W Posted May 23, 2018 Report Share Posted May 23, 2018 5 hours ago, Tom King said: If you know offhand how much of a vacuum does vacuum bagging veneer call for, an answer would be appreciated? If you don't know right off, don't worry about it. I can look it up. Here is a good article on pumps of wood veneer, by Joe Woodworker. https://www.joewoodworker.com/veneering/EVS/vacuum-pumps.htm Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 23, 2018 Author Report Share Posted May 23, 2018 Thanks Ronn. That's the perfect info I needed. This is an oil bath pump, but I can keep it away from any finishing area. Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 28, 2018 Author Report Share Posted May 28, 2018 Looks like that one raised some worry about sucking glue through veneer, so that won't be a worry. I found the next larger Robinair on CL for about the same price. It's a 2 stage with several other useful bells and whistles. It'll make the air conditioning work go a lot faster, but will be too much to think about using for a veneer bag, so I'll worry about that later, a different way. http://www.testequipmentdepot.com/robinair/vacuum-pumps/cooltech-vacuum-pump-6cfm-15601.htm Quote Link to comment Share on other sites More sharing options...
wdwerker Posted May 28, 2018 Report Share Posted May 28, 2018 Adding a simple ball valve to introduce a slight leak on purpose lets you control the strength of the vacuum. Guys like me and you don't need complete automation. Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 28, 2018 Author Report Share Posted May 28, 2018 Can you trust the bag to hold if you pull it down to a certain point, and leave it? With the digital gauge, that would be easy. Quote Link to comment Share on other sites More sharing options...
wdwerker Posted May 28, 2018 Report Share Posted May 28, 2018 Yea, I leave my pump running for hours on end. Analog guage works fine for me. Quote Link to comment Share on other sites More sharing options...
Coop Posted May 28, 2018 Report Share Posted May 28, 2018 If the pump is overwhelmingly, a couple of ice pick holes in the bag will relieve the pressure Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 28, 2018 Author Report Share Posted May 28, 2018 I meant, could I close the valve on the pump when it pulled the vacuum down to a point, turn the pump off, and expect the bag to hold the vacuum? This pump has a valve that can close the system separating it from the pump. One thing I like about that digital gauge is that it tells you if the system has a leak in it. http://www.robinair.com/products/digital-micron-vacuum-gauge I'll be doing AC work long before I need to do any veneering, but it would be nice if I didn't have to buy another pump when I do. Quote Link to comment Share on other sites More sharing options...
wdwerker Posted May 28, 2018 Report Share Posted May 28, 2018 Most vacuum bags leak a little . Hose, fittings or the bag closure. The vac press system units have an auto on pressure drop switch. " Joe Woodworker's site has plans so you can build your own system using almost any vacuum pump. Quote Link to comment Share on other sites More sharing options...
Tom King Posted May 28, 2018 Author Report Share Posted May 28, 2018 Thanks. Quote Link to comment Share on other sites More sharing options...
Mycrossover Posted June 2, 2018 Report Share Posted June 2, 2018 I don't suppose you own a big air compressor? They sell venturi accessories to do car air conditioners, so they pull a lot of vacuum but they use a lot if CFM to do it. They have no moving parts and are cheap. See HF catalog.Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
Tom King Posted June 2, 2018 Author Report Share Posted June 2, 2018 My two largest compressors are 5 and 10 hp. I already have the pump, and a friend has all the other stuff, and the know-how. In fact, he's moving his giant toolbox into my mechanic shop, but is waiting for someone to come get it with a rollback. He has a place on a half acre lot on the lake, and doesn't have enough room to work on stuff, so I offered him the use of my metal/mechanic shop. This vacuum pump has opened up all sorts of possibilities. My HVAC guy, that I've sent a lot of work to, has a commercial gas pack that he's giving me for that shop that he pulled off a commercial building. It has a 3 phase motor, but I don't mind putting a VFD on it. It'll just feed a big hole in the side of the building, for now, but it'll be nice to have AC any kind of way. Quote Link to comment Share on other sites More sharing options...
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