Official Luthiers Forum!

Hi all,

Lost all my stuff off the laptop when it crashed a couple of months ago...now I'm ready to start work on some jigs, rigs, and jimcracks...and no photos or plans! Anyone have the pix of the vacuum fixture for top and back bracing that was up here a while back? I think it may've belonged to Bob Garrish, but not sure...any help would be appreciated!

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http://www.presnallguitars.com

Hi I built one of these
http://www.kennethmichaelguitars.com/vacuumclamp.html

worked OK to be honest this works better for me

http://www.veneersupplies.com/products/ ... 2-x-2.html

slip it in with a radius dish under the top or back and you are good to go.
if I could do it over I would probably go with a bigger bag to accommodate the radius dish easier

Richard

This is worth checking out at Joe's too
http://www.joewoodworker.com/veneering/ ... -press.htm

Here's a pic of mine while gluing down the bracing on a 5 str. AB I'm working on;



I built it out of a few scraps of Cherry I had sitting around and it works great. I used some of the gasket material on the bottom I got from JoeWoodworker's site and just sit it on top of a a piece of plexiglass for a good seal. I use one of my sanding dishes for the top to suck down to the proper radius. The bladder is some rubber sheet stock I picked up on ebay that is basically sling shot rubber. Tough stuff and works great! Still need to build the bridge fixture though.

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Bill Hodge


One does not simply, own enough guitars!

Looks good Bill! Thanks for the info guys...I think too the one I saw was mega-simple...just a plexi frame with weatherstripping on the bottom that is big enough to fit over what you're gluing and not much more...I just need to take the time and get one of these done...I had one that I bought off eBay years back but sold it and went back to the go-bars...now I'd like to have vacuum again just to supplement the go-bar deck...my bridge fixture is the best thing that's happened to me in a while.

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http://www.presnallguitars.com

The 'old version' of mine were made from a chunk of 0.75" plexi. Gasket on the bottom, and a membrane bonded to the top. The main cost was the big chunk of acrylic. The newer ones were aluminum, and the biggest cost on those was the guy TIG welding them

Seriously, you could do it with a hose with some holes drilled in it, a garbage bag, a flat piece of MDF, and a rubber band or zip-tie...and I have!

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Bob "McGyver"!

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http://www.presnallguitars.com

Here's mine that I'm using for Ukes. Dished workboard and vacuum press frame. Scale it up as large as you want.

Just made out of some scrap, and the vinyl is just some stuff I picked up in the off cut bin at the local fabric shop. The whole thing didn't cost $10.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

Good stuff Allen! Thanks! Man, I gotta get on this...but first, the guitar Troji....

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http://www.presnallguitars.com

It's science, baby!

In the end, it's just atmospheric pressure. There's no force trying to harm the membrane other than the possibility of a deep pocket or uneven air-removal causing tension somewhere. You can set 1000lbs of weights on a garbage bag on the floor and not punch through, and this is no different.

If using a bag, I tend to make a 'spider' as well. Take a piece of vinyl or plastic tube and chain few T or manifold sections on the end of it so that you have a bunch more tubes coming out the end. Looks sort of like a flower, actually. Then drill lots of holes in everything except the first, long tube, which will be hooked up to your pump and come out of the bag. This prevents you ending up with the tube self-sealing, as there are too many openings to get sealed up before the vast majority of the air is evacuated. It performs the same function as the 'bleeder' membranes and things that people throw in to stop the vacuum port from self-sealing.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Oooh, be-haaaave!

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http://www.presnallguitars.com