Official Luthiers Forum!

How do you guys who vacuum clamp your bracing hold them in place until the glue sets?

I don't do it yet but here's a way to make a frame.
http://joewoodworker.com/veneering/vacu ... -press.htm

Thanks Chris, but I was wondering what techniques people are using to hold the braces in place while lowering
the lid.

Or if any of you are using a bag, how are you keeping the bracing from sliding around
until there is vacuum?

I've seen some put small pieces of tap across it. I think it also depends on what glue you plan on using. I believe the nice thing about the vaccum frame is it pulls down evenly on the braces. A bag to me would seem to be the wrong choice and take too long especially for HHG.
I'll be interested to see what the others say about it.

I just extend my X legs and top and back braces to edge or little proud of plate. I glue a small block to the dish gluing plate in so plate comes up or almost to the block. I piece of wood on top of the block so can turn it and if needed tighten and loosen a little. Once have glue on brace carefully place it on the plate and then turn little clamp made onto the brace end. I do a little dry run first to get clamp set so will place on brace without having to adjust with glue on the braces. I have cauls made of lexan (sp) for the finger braces which helps place them in right place and hold them in place while gluing. Use additional cauls on top of top/bace braces for added pressure when tunn on pump. I was setup so could do 3 tops/backs same time. I pretty much glue bridge plate in first, then UTB, and last the X, tone bars and finger braces at one time.

My frame is made up like Bob Garrish rig, however, use angle iron (if what called) to hold and screw the rubber to the frame. I get the foam from Joe (woodworker) it comes in long strip and does better for me anyway than stuff from auto stores or home repair places.

Stan,
Got any pictures.
I was over at Frets.com and was looking at Foxes setup. One thing I thought was a pretty idea was that he has a radius glue dish that is setup to vacuum the top or back plate in place to form the radius in the plate and then the braces don't have to push on the flat plate. I was thinking that if that was the case one could just hold the brace in place if using HHG pushing the glue out and then after a few seconds the HHG would have enough stick to keep it in place while the frame is lowered and the vacuum applied. Would that work? Because I found that when I glued the back on using HHG just the weght of the outside mold pushing down on the back for about 5 seconds made it a bit tricky to adjust the back plate a little. Seems to me once you get the squeeze out that a bit of suction seems to happen. I was thinking it would be enought to keep the braces in place. Is my logic all wrong here ? Like I said I haven't used a frame yet, just gobars. But very interested in the vacuum frame.

Chris I also have dedicated radius dishes for the vacuum rig. For discloser I learned and fashioned this from working at Bourgeois. Like said I do a dry run to make sure everything is fitting and the ends will clamp and hold down things well.

When I put the braces on the plate I hold it down a for a few seconds, but that does't keep them to the plate all that well just enough to I gues get glue on the plate and brace.nce every thing in place put cauls on top of braces to add pressure. Nice thing about vacuum it pushes straight down and not get movement of the braces as they adhere to the plate. My plates are radius so when pressure from clamp is applied pushes braces straight down onto the radius, never a problem this way.

I don't have pics or know how to post them. I will try and get some of the frame and can email them to you.

OK, thanks .

Go and look at the Taylor website, 'Factory Fridays', they show in detail on the bracing video how they use a template to hold the braces in place until they lower the vacuum top.

Colin

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Dedicated dished workboards (interchangeable - 15' and 25" Radius) and just a small piece of tape over and/or on the ends of the braces. Close the lid..."suck" for 5 min. , open, remove tape, reclose, "re-suck" for 15-20 mins. Done ( I then let dry for 24 hours). LMI luthiers glue.

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

I do not even have a camera. Will see if can get one and then how to post them, but may be awhile. I got this from Dana's shop.

I had difficulty using a vacuum frame at first. I tried to lay the braces down all in one shot and things moved when I closed the lid. Then I glued the braces down in shifts and that worked out much better but took more time. It can be done without using pins to hold the braces in position, if you use the right technique of seating the brace by hand.
I found that using go-bars makes holding the braces in position while l move on to the next brace works the best, when all the brasses are set you can remove the go-bars and then close lid on the vacuum press to finish. I did that once and realized that it would be better to just leave the go-bars on and not use the vacuum. You can get the squeeze-out without having to remove the pressure on the glue-up.

Someday I may try using the pins on the dish technique.

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Rich S

"The inconvenience of poor quality will linger long after the thrill of a bargain has been forgotten"

The other thread about vacuum clamp rekindled my interest in the vacuum system. Anyone know if Stan was able to get some photos of his Dana-style clamping system?

After watching the Taylor video.. does anyone try this using the hot hide glue? If so, how much time does it take vs. just using go bars?

_________________
Chris Oliver
Infinity Luthiers
...in the shop.

live every minute...

Chris,

I use Fish Glue and simply use some of the blue painter's tape to hold the braces in place. After 15 - 20 minutes I release the press, remove the tape, and reapply the press for about another 30 - 45 minutes. Works great!

_________________
Bill Hodge


One does not simply, own enough guitars!