# vacuum and guitar making



## ajcoholic (Feb 5, 2006)

In my old shop, I had a smaller vacuum pump for about 20 years, and a few various sizes of vacuum bag (from 48" by 96" down to a foot by two feet) that I used to pressing veneers - mainly in furniture repair and the odd time I would use some figured veneers to make a table top, etc.

I did use some veneers in the past (like on my large semi hollow arch top, covering the bent plain maple sides with highly figured maple veneer) in my guitar making, but the idea to veneer the Korina body with figured Korina veneer got me thinking to share some ideas.

I bought a new vacuum pump recently (from Vacuum Pressing Systems -- Your Veneering Solution! - the 6 cfm model) which is much higher flow than my old one. Thus is going to allow me to not only use the vacuum for pressing/clamping, but also for work holding.

I bought a pair of aluminum "pucks" - which you screw down to a work table, and place your material on top of. The vacuum pulls the work down, like a clamp. When you want to release it, there is a foot switch to cut the vacuum.

I see this will be a great thing for, say, holding down a guitar body to rout all around the edges without having to move clamps, or worry about marking up sanded faces. Custom frames to hold things can easily be made by routing a groove into a non porous material (or MDF if you seal it with a few coats of finish) and run a neoprene O ring material around it. Drill a hole for the vacuum line to press in and there you go... similar to how work is held down on a CNC machining center.

With vacuum, you can pull around 13 to 14 lbs/sq inch which is equivalent to about 2000 lbs per square foot. More than enough.

When I veneer my body I will show picks in the other thread.

I just thought I would share what I know in terms of vacuum bagging, and work holding with the rest of you.

AJC


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## Milkman (Feb 2, 2006)

I've seen vacuum used to sandwich layers together in the construction of sailboards and other fibreglass laminates. Makes sense that it would work for guitar bodies as well.


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## ajcoholic (Feb 5, 2006)

Yes, in composites it is used to make everything from snow boards and surf/sail boards to full scale airplane components.

I actually got my vacuum pump for making composite model aircraft parts, ie, vacuum bagging carbon and FG onto foam cores for wings etc. After I went to college in the early 90s I discovered how handy it is to use in woodworking as well.

You never see decorative wood veneers used in guitar making (except for headstock overlays) although many lower priced guitars use a curly/quilted maple veneer over a solid cap, or say a two piece alder veneer over a multi pc body...

I have some beautiful Madagascar rosewood veneer I bought in 1994 - which is now unavailable due to CITES limitations. I think I will experiment in the future with trying to laminate up tops, etc with some of the nicer veneers I have.

Imagine a 335 style guitar with a rosewood top? Yummy! 

AJC


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## shoretyus (Jan 6, 2007)

ajcoholic said:


> Imagine a 335 style guitar with a rosewood top? Yummy!
> 
> AJC



Oh the temptation....


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## Milkman (Feb 2, 2006)

I think a 335 style guitar made out of acrylic would be nice.


(now where did I put that asbestos jumpsuit...)


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## ajcoholic (Feb 5, 2006)

Milkman said:


> I think a 335 style guitar made out of acrylic would be nice.
> 
> 
> (now where did I put that asbestos jumpsuit...)


Well, I am a wood man at heart so I will leave that to someone else 

AJC


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## ajcoholic (Feb 5, 2006)

Here is what the veneer looks like before, while its in the bag, and after its been taken out... when you put it into the vacuum bag, I use two pieces of plywood with packing tape on it to even out the pressure, and also prevent any glue seeping through from gluing itself to the boards.

AJC


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## ajcoholic (Feb 5, 2006)

after its been cut out the veneer is permanently glued to the faces of the body - and since the wood is the same they will move the same, and stay stable.


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## ronmac (Sep 22, 2006)

Vacuum clamps are good for more complex tasks, too. You can see how Larrivee clamps braces to the soundboardand back here Larrivee MainLarrivee :: Acoustic Build Tour :: _002


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## ajcoholic (Feb 5, 2006)

If I ever do more than I currently do, I would invest in one of the vacuum bag tables - where you just lower the upper frame/bag down onto the stationary part. But they start at over $3000.

AJC


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## YJMUJRSRV (Jul 17, 2007)

gone fishing


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## ajcoholic (Feb 5, 2006)

No noise from my new pump... seriously it is a high flow, low rpm pump. Very quiet. Many of the older pumps are noisy, as was my older one. The new one from VPS is awesome! But, its not cheap.

AJC


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## taylor96 (Feb 17, 2008)

Very interesting thread ajc.. thanks for sharing your stuff...


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## parrisw (Jan 24, 2011)

Vacuum pump on the cheap, look for an old AC machine from an auto shop, they pull a deep vacuum and are usually very quiet. I pulled one out of our old one, cost me nothing, though I've never used it for anything yet.


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## closetmonster. (Nov 26, 2009)

I've seen very similar methods with regards to longboard building. Not sure if you're interested at all, but those guys are always coming up with new methods of vacuum-bagging and sealing boards.

http://www.silverfishlongboarding.c...rary-board-building-tips-resources-ideas.html

Might be good for a quick read, all kinds of stuff in there. Unfortunately you need an account to view most of the pictures posted.

-cm.


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