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I'm trying to build one of these, and am wondering about a vacuum compressor. Wondering how much power (PSI) is really needed? Got my eye one one that specs 20" HG MAX. VAC., 1.5 CFM OPEN FLOW, 10 PSI MAX. PRESSURE. Is this enough for a little vacuum bridge clamp like the LMI?
And BTW, I've already looked at the joewoodworker site, and while it is informative, it doesn't address my application.

CrowDuck

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Chris Nielsen
Soquel, CA.

As Mario would say, Google is our friend Here is the link to the specs for the LMII vacuum pump. If I was buying I'd probably use a similar setup, not knowing what else I might use it for in the future. Look on ebay for GAST pumps with the same specs. Hope this helps.Don A38778.8153009259

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Don Atwood
Arlington, VA

My fridge compressor system sucks 28.5" which is about as good as it gets.
I personally wouldn't be happy with less than 25".
If you are not building a large press for top / back bracing, you don't need a ton of CFM.
Many of the Ebay vac pumps are used & were used in medical labs & hospitals. There is a real possibility of biological contamination.
A very useful site is joewoodworker.com   
Daniel M38778.8329282407

check out Joe Woodworker's Site it has more info on this than you can imagine. They have plans for a very slick set up.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Hey Daniel. Any chance you can give us a quick and dirty instruction on using a fridge compressor?
ie: do you need to do much modification, if so, what, etc...

Oh and of course, Pictures.

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Well Rod;
First, it took four tries before I found a couple of used compressors that worked... Get them from the local dump or appliance service shop AFTER the freon has been removed.
One compressor will easily run a bridge clamp, but I need two to get the bracing press to suck down properly.
Make sure the capacitor(?) & thermal cutout are still installed. (usually under a little bakelite cover attached to the side of the compressor) You'll probably have to cut the main power cord outside the box & install a new plug.
The compressors have at least three copper hoses. Cut them off as long as you can. Dump most, but not all of the oil out & with all the pipe ends clear of debris, plug the thing in. One pipe will blow & one will suck... flatten & solder seal the others.
The pressure side pipe will probably blow out some oil for a while, so take appropriate measures. Run it for a couple of hours. or 'till it stops blowing oil out with the air.
A resevoir is a must. I used an old barbeque propane tank. Just "T" it into the suck line using cheap vinyl tubing & plastic barb fittings. You'll need to buy brass for some of the fittings, esp. the adaptor for the propane tank. A three position marine fuel valve makes directing the vacuum to different appliances very convenient. (these valves usually have a mid way position between the indents which will unlaod the vac so you can remove the clamp. I put an inline fuel filter in the vacuum line near the compressor to catch debris that can damage the pump.
joewoodworker sells the guages & fittings you'll need at a good price.
The fridge compressors are really quiet & work quite well but when I can afford it I'll buy a real vac pump. I figure that they were intended to run on a full tank of oil... With most of the oil removed I expect they will not last forever.
My kid has the camera for a while, so I can't post pics. There is a link on Joe's site to a fridge compressor vacuum press system. I used it as a reference when I built mine.
If money is not an issue... Joe usually has rebuilt pumps at a good price. Much more convenient, but maybe not as much fun.

Thanks Dan, Sounds a little complicated, I'll check out Joewoodworker for the fridge compressor vacuum press system for more details than decide the direction.

I do like the fun of building things to build guitars.

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

I once sent Joe an email explaning what I was doing and asked him to recommend one of the many set ups he offers. He got right back with me...now If I could just figure out where I put that info.

If you have an air compressor that will generate 90 PSI, one of these 'might work' from Harbor Freight for $15. Says it pulls 28.3 Hg @ 90 PSI at sea level.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnu mber=3952

And I wonder if this would work? Claims to hold 30 in/Hg.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnu mber=92474


CrowDuckcrowduck38780.6969444444

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Chris Nielsen
Soquel, CA.

Here is a picture of the system that I built after talking to Dan and then getting my buddy who is a refridgeration dude to help me out with the parts and the putting it together. I don't have any inline filters, probably a good idea although there are lots of these compressors around and it is pretty easy to replace them. As Dan said the tank is a vacuum reservoir. You suck it into vacuum and then when you open the valve and turn on the pump you have that vacuumed tank to get you started. It takes only a couple of minutes to empty the tank with this pump. It is so quiet I am considering a light that goes on with the power so that I don't leave it running on accident.







Hope this helps!

Shane

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Canada

COOL, great set up Shane!

Shane,

That's a 'wild setup'! Are you using it with a vacuum bridge clamp, a brace clamping press, or both? If with a vacuum bridge clamp, did you make your own, or buy one from LMI? If you made your own, could you post some pictures, and a description?

Thanks,

CrowDuck

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Chris Nielsen
Soquel, CA.

Hi Chris, I have an LMI Bridge Clamp that I bought from one of our OLF members. That is waht I built this unit for. But I think that with the reservoir tank it would work for braces also. But the go-bar deck is so quick and easy that I don't know that I would get to building a brace press for some time. Dan Minard (DanielM) has built all of his presses and is really the guy to talk to about that. This set up does work very well.

Shane

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Canada

Shane,

Thanks, I'm not interested in a brace press, I use HHG and go-bar for braces. Only interested in vacuum for a bridge clamp, and am trying to make my own bridge clamp.

CrowDuck

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Chris Nielsen
Soquel, CA.