Official Luthiers Forum!

Hi all-
I've been lurking here for some time and am now jumping in. I built
number one (classical, IRW, cedar, Fleta bracing) in Robbie O'Brien's
excellent class at Red Rocks Community College in Denver and am
nearing completion on number two.

I bought LMI's bridge vacuum clamp, but the pump from them seemed
like overkill since I believe neither hard vacuum nor large volume capacity
is required. Does anyone have any experience using a hand vacuum pump
- like the type used for automotive brake bleeding? Any opinions on
whether or not this could work?

Thanks,
Chris

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http://coneryguitars.com

Kill your television!

Chris, check ebay for a pump. I bought a brand new in box Thomas pump for less than a hundred bucks including shipping.

The problem is you need continuous vacuum to use the bridge clamp. Mine begins to lose vacuum as soon as I turn off the pump. I think a hand powered pump would have to be monitored continuously to make sure you still had vacuum on the clamp.

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Dave Rector
Rector Guitars

It will. Short of a really tight vacuum bag setup, it's pretty much impossible to hold a vacuum. Anything using gaskets won't hold a vacuum. The bag thing will only work with airtight valving and a welded-in bag connector.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

there are a lot of viable alternative sources of vacuum, but a hand brake bleeding pump is not one of them, unless mayhap you have the six million dollar man's bionic arm fitted.

as mentioned above, you can get vacuum pumps much cheaper.

if you are wishing to use vacuum in your building i would urge you to have a long, hard look at joe woodworker's site. whilst a lot of what he talks about is directed at veneer press operations, it is just as applicable to vacuum clamping. have a look at his prices as well. they are probably as good as you will get for new gear without searching and waiting for the great buys which pop up on ebay from time to time.

I tried using a hand vacuum pump for vacuum bagging composite wings for model airplanes. It worked, but so did I. By the time that the epoxy finally set I felt like I had arms like Popeye. I built a nice setup using an old refrigerator pump. It worked great, and cost nearly nothing to build.

Al