back brace gluing problem

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back brace gluing problem

Postby Greg Steil » Fri Feb 05, 2016 12:39 pm

OK hive mind, ideas please. The problem, loose back braces on Weissenborns(my own build). Very thin body, so the Stew Mac brace jack won't work(too tall) and I can not get my hand very far into the sound hole. Any ideas in how to get the "tool" in there what ever it may be? Thanks.
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Re: back brace gluing problem

Postby David King » Fri Feb 05, 2016 12:57 pm

Perhaps a vinyl ball could be partially inflated inside?
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Re: back brace gluing problem

Postby Greg Steil » Fri Feb 05, 2016 1:50 pm

now thats cool, I had thought of something pneumatic, but figured I'd blow up the guitar. I'll explore that stuff....I love this place.
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Re: back brace gluing problem

Postby David King » Sat Feb 06, 2016 12:15 am

Actually you might want to experiment with a mylar balloon as it's a low-stretch material and you could achieve a higher pressure more quickly that way but you wouldn't have the convenience of the needle inflator/valve.
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Re: back brace gluing problem

Postby Michael Lewis » Sat Feb 06, 2016 3:37 am

Neodymium magnets. StewMac has some, also K&J Magnets. Sometimes American Science and Surplus has some too. K&J has by far the best selection. You might spend some time at frets.com to see how Frank Ford uses them.
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Re: back brace gluing problem

Postby Greg Steil » Sat Feb 06, 2016 8:27 am

I do have some magnets, and am experimenting with placement tools. I have also developed a couple accessories for the Stew-Mac jacks but they don't fit.
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Re: back brace gluing problem

Postby Clay Schaeffer » Sun Feb 07, 2016 10:12 pm

You could try wedging a post (like a violin sound post) between the top and brace. Use a pair of hemostats to extend you reach.
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Re: back brace gluing problem

Postby Ryan Mazzocco » Mon Feb 08, 2016 1:20 am

Clay Schaeffer wrote:You could try wedging a post (like a violin sound post) between the top and brace. Use a pair of hemostats to extend you reach.

That's what I was thinking. Maybe even use of those violin post setters to do it. It's not that expensive of a tool if you don't have one.
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Re: back brace gluing problem

Postby Greg Steil » Mon Feb 08, 2016 9:28 am

I have the post setters, and have made two sets of much larger ones for Bass and Cello, and have used long Hemostats as well. Learning as I go I guess. The brace closest to the bottom end is gonna be a real trip. Thanks for all the advice!
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Re: back brace gluing problem

Postby John E Giarrizzo » Mon Feb 08, 2016 9:52 am

Here is what I did on a guitar that I restored. I had to replace a brace.

I used a tapered rectangle of wood with rounded edges. I inserted it at a sight angle until it made contact with the brace and opposite side, then twisted it to apply pressure.
Jeg 100_7070a.jpg
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Re: back brace gluing problem

Postby Peter Wilcox » Mon Feb 08, 2016 12:21 pm

I don't know how long your hemostats are, but ring forceps are handy for getting into inaccessible places, and have good clamping pressure. You can even clamp two together for longer reach.

Excellent for removing stuff that falls into the garbage disposal.

http://www.amazon.com/9-1-Locking-Spong ... ing+forcep
Maybe I can't fix it, but I can fix it so no one can fix it
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Re: back brace gluing problem

Postby Paul Breen » Mon Feb 08, 2016 2:14 pm

Magnets can work quite well for loose brace repair in difficult places but there is a bit of a learning curve to their SAFE use.

I made these very simple fixtures, with the magnets double stick taped on. I think the image gets the idea across and solves how you get a magnet to balance on top of a brace. The magnets are 1" X 1/8" Neodymium, four used inside and 4 outside is usually enough magnetic pull the get the job done. If you pay attention to the polarity, and you should, you can also use their repulsive power to arrange the fixtures pretty close to a neighbor. You can see I have mine labeled + and - so I can keep track of them once glue has been applied. Clear the deck of anything magnetic in proximity to your project! Lay the magnets out on the bench ready to go in order, organization will help negate the chance of flying magnets. With a sound hole that is large enough to get a hand in there, place the magnet fixture with one hand and hold it in place, then bring the other magnet on the outside to it while grasping it firmly in some protective leather. With an instrument that the sound hole is too small or the brace can't be reached, use something like a steel palette knife, taped to a dowel rod if necessary, and put it into position and hold it there while bringing the outside magnet set into place.

Practice your set up! Do a dry run of both arranging the magnets on the bench and placing them in the instrument. If you have never messed around with Neodymium magnets, play around with them before they ever even get near your bench and get a feel for them. Watch out though, they can raise a blood blister on your fingers before you even know what happened, they are VERY strong! The last thing you want is to have some slip up during placement and have magnets go flying around in an instrument, they can easily crack or break thin instrument wood if not carefully handled.

magnet inside uke.jpg

magnet outside.jpg

magnet fixture.jpg


This is the rig I use to get glue delivered. A Stew Mac glue hypo, some 5/32" brass and vinyl tubing and a hypodermic needle. The Brass tubing is bent/ shaped for the job. I have a good assorted collection of shapes now.

I generally use original Titebond, diluted some with water but have also used it with hot hide glue. The problem with using hide glue in it is keeping it warm enough to not gel. I solved that by using an Infra Red lamp and the glue injector on a small sheet of Black laminated board. Infra Red won't heat up shiny objects but it gets the Black laminate good and hot. Use the injector combined with thin palette knives to get the glue under the loose brace. Have a reaching tool ready with a small bit of rag fixed it that will be dipped in water and used for glue clean up.

Glue rig.jpg

glue rig needle.jpg
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Re: back brace gluing problem

Postby Clay Schaeffer » Tue Feb 09, 2016 10:30 pm

I like John G.'s idea. It looks less complicated than the "sound post" idea I suggested. I'll have to remember that one.
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