How to fix a loose brace?

[sjusk]

I have an old two-pointer by Guild, and some time ago I noticed a sag under the bridge in the treble side. I loosened the strings and put it away, and just played my other mandolin.

Yesterday (by impulse) I inspected it with a mirror through the F-hole, and saw that the brace had come off the top towards the neck. A little over 2 inches of the brace has no contact with the top. There was some old glue on the brace where it wasn´t supposed to be, so I think it has been repaired before, not with succes though.
I took a thin steel rod, flattened it in one end, and bended it to an angle of 90, and it went in easily between the brace and the top.

Now, my question is: Is there any way I can fix this from operating through the F-hole? I think I can remove the old hardened glue and put some fresh glue there, but how to hold the brace and the top together while the glue dries up?
(Talking of glue: What glue to use? I´ve read that the only real thing is hide-glue. What is that exactly? Forgive me, I am not American or British).

I am no luthier either, but have done some minor repairs and changes on mandos and guitars.
Maybe this repair idea is just crazy - and if it is, please tell me.
If it can be done - please share your knowledge! I´ll be a willing student.

I´ve looked through the threads, but haven´t found a similar posting. I hope I haven´t missed one.

Thanks,
Søren

[sunburst]

That can be fixed through the sound hole, but not easily.
You have the right idea. If you can clean off the old glue, you've done the hard part.

Hide glue is indeed one of the best glues, but not always for repair. Titebond will stick more reliably to old glue joints that can't be cleaned thoroughly, so I would recomend it for this repair.

To clamp, you'll likely need a cam type of arangement on the end of a stick so that you can put it in through the F-hole and prop it up under the brace, then clamp the outside of the body to close the joint.

Practice several times to get the procedure down, adjust the length of your prop, and when the joint is clean, the prop is the right length, and you can do the whole procedure quickly and easily, apply the glue and go for it.

Ask more questions as you go, and good luck!

[sjusk]

John, thanks for your guidance and advice, they´re most useful!
It´s gonna take me a little while to get at it, I´m rather busy the coming weeks, but I´ll probably be back with more questions as I get into the "surgery" Thanks for offering your help - I appreciate it!
Now I know it can be done.

Søren

[Rob Grant]

Old, oxidized contact surfaces can be a problem to properly glue. If you haven't had a lot of experience with instrument repair and the instrument isn't some expensive top-of-the-line item a repair through the f hole is worth a go. Like Sunburst says, do a few "dry runs" before you go in with the glue. I don't know if it's possible, but you may be able to clamp using a couple of magnets (inside/outside). It would be a good idea to put a small piece of plastic sheet on the inside bottom of the instrument directly under the area to be repaired to catch any drip. If you are using Titebond, work out a way to clean up "squeeze out" before the glue sets.

Another thing that helps with this sort of internal repair is a good light source. I use a small 12v auto dash globe and socket wired to an old computer AT power supply to provide hands free illumination. The globe and socket is on
a thin, flexible twin lead. I push the globe and socket through the opposite f hole and place it in a positon where it will light up the area I am repairing.

[sjusk]

Doing the procedure as a "drill" a couple of times getting familiar with the proces sounds like a good idea.
I think the tricky part is to clamp the brace and the top "in just a second", and I have to practice on that before the glue goes in. I guess I have to prop it.

Both you and John mention Titebond. Is that a type of glue or is it a brand? I´m not sure I can get it in Denmark where I live, but maybe we have something similar?
Is it a special luthier´s glue? I guess I could mailorder it via the internet, if it´s not available over here.

Thanks for the advices, I´ll let you know when I´m ready to get at it.

Søren

[fatt-dad]

Warning, I'm no luthier!

As an amateur and also working on an entry-level mandolin, I successfully did a very similar repair. I could visualize what needed to be done and just did it. My biggest struggle was getting the clamps in place. I found that I was able to cut some paint stirrers to the correct length to insert through the f-holes. I had the paing stirrers running from the treble to the bass sound holes, resting on the loose brace and across to the other brace. I had a similar arraingment with paint stirrers on the top side of the mandolin and then used fairly standard u-shaped clamps to apply the pressure. The clamps had to fit through the f-holes in order to "bite" the paint stirrer on the underside of the top.

Maybe my description seems confusing. I had nothing to go on and just used my ingenuity. That said, it worked. In my specific case, there was no top sinking, just a funning overtone from the vibration of the brace, so my repair corrected the problem. That said, had I not done the repair, there is no doubt that a structural problem would have presented itself eventually.

(Ever heard of a company called Kompan? My wife sells their playground equipment in Virginia and they are Danish company - great stuff!)

fatt-dad

[Bill Snyder]

Here in the USA Titebond is a brand of aliphatic resin glue. It is a common woodworker's glue. Elmers carpenters glue is a similar product, but most luthiers seem to prefer the Titebond brand (manufactured by Franklin International). One thing about the Titebond is the bottle needs to be fresh. After the glue gets over a year old it starts to degrade. There is a date code on the bottle. I believe the first number is the year (ie 4 would be 2004) and the second character is a letter corresponding to the month of manufacture (ie A is January, B is Febuary, etc.).
DO NOT use Titebond Liquid Hide Glue. I have not read any positive reviews of this product.
Here (http://www.stewmac.com/shop/Glues,_adhesives/Wood_glue/Franklin_Titebond_Glue.html) is a link to Stewart Macdonalds listing for the Franklin Titebond. They deliver to several countries around the world. I suspect that the shipping would make this an expensive way to purchase glue.

[sjusk]

fatt-dad, the idea with the paint stirrers sounds pretty good. As I see it it means a minimum of operating inside the mandolin, and that must be an advantage - at least for me and my clumsy fingers. I´ll make a note of it!
yer, I know Kompan very well; it´s about 30 miles from where I live, and I used to know a guy who worked there.
It was recently sold to a Swedish company, but that was actually good news - they needed an "injection". (well, who doesn´t? It´s just that I can´t find any Swedish companies that wants to buy me....)

Bill, thanks for the information on Titebond. I checked the link to Stew-Mac, and it´s about 18$ to get it over here. I´ll check around over here and see if it´s available before ordering it, but I guess I´ll end up getting it from Stew-Mac.

Thanks for sharing ideas and infos!

Søren

[Chris Baird]

There has got to be a swedish brand of aliphatic resin. No need to pay $18 for a bottle. Just get the most popular yellow wood glue from your local hardware store.

[PaulD]

Søren,

I would think you could find somebody on that side of the pond that sells Titebond or Elmer's. I did a quick Web search and got hits in Sweden, France, and UK... but nothing in Denmark.

On a different note... some more of my off-the-wall ideas.

Has anybody ever tried using something like a balloon or maybe a section of old innertube to clamp a brace? You would want to be careful... maybe even clamp the outside so you don't blow the top and back off the instrument. Maybe this is more work than "normal" methods. I've never tried this, but it sounds like something I'd do! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

How about magnets? Okay... I won't elaborate on that one because I haven't worked it out in my head, but I thought I would "plant a seed" in case there's something there.

I'd better be careful... I'm going to get myself a reputation as being a crack-pot on this list! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif Or maybe it's already too late!

Paul Doubek

[fatt-dad]

I'd better be careful... I'm going to get myself a reputation as being a crack-pot on this list! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif Or maybe it's already too late!
Just wait 'till I post my fretboard ramp photos. We'll be in compitition.

f-d

[sunburst]

Paul, I don't kmow about a balloon. If you could concentrate the force on the brace, where it's needed, sort of like a pneumatic jack, it might work.
I do use magnets for some things. Usually loose braces in a mandolin have been forced away from the top by string preasure on the top, and take more force than the magnets that will fit through the F=holes can apply.
The method I outlined earlier with a prop works like the balloon would. It's like setting a sound post under the brace, then clamping the outside of the mandolin with the clamp pushing at the ends of the sound post to close the gap and clamp the glue joint.

[PaulD]

John,
Like I said... the balloon might be more trouble than the conventional approach, i.e. cutting a prop. It sounds like a reasonable and time-tested approach. It would be just like me to try to reinvent the wheel before caving in and buying a conventional set of tires! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Of course, now my mind is going with the pneumatic jack/prop idea. Make a little telescoping jack, maybe with interchangeable ends. It has a rigid or semi-rigid tube for the air supply that can also be used to place it, and it attaches to the compressor with a regulator so you don't perforate your instrument. You could position it and expand it into place... or you could go to Goodyear and get a stock set of radials! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Paul Doubek

[sunburst]

Paul, Make 'em cheap enough, and in enough sizes, and I'll buy some!
(They'll need a locking mechanism so you don't have to leave the compressor hooked up to them while the glue dries.)

[Rroyd]

Model railroaders use small cylinders that operate on compressed air to operate track switches and other accessories. I would suspect that some of that equipment would be small enough to be able to be adapted to use for repair work. You could plumb in a tubeless tire valve stem to the input line, and use a hand pump to be able to control the cylinder expansion. My only reservation would be that they might not be able to exert enough pressure. I don't know what those specs are on them, but it might pay to check it out. Years ago I made several small jacks from turnbuckles, (the smallest being about 1 1/2 inches closed) but you have to be able to have enough access to operate the turnbuckle, so something operated by remote control would solve that problem.

[sjusk]

It seems I managed the operation with succes!

I found a good strong wood-glue (local), and thought I´d give it a try instead of importing some expensive Titebond.
First I removed as much of the old glue as I could, cleaned the joint, and started to work out a method holding the brace and the top together during dry-up. I tried a fitted piece of wood with a wire attached near it´s top and another wire attached near it´s bottom. After struggling with it for a while, I realized I wasn´t able to raise it properly, and looked for other ways.
My "tinyest" clamp wouldn´t go into the f-hole, I thought about it, and decided to narrow it. I started my electric grindstone and took the clamp down to a size where it went in the f-hole. I tested it, and it worked great! (Of course I got an odd looking clamp now, but who cares?)

Not much more to tell: I put on the glue and clamped it.

The clamp was on for about 36 hours at a normal room temperature, and today when I finally tuned it, more than 40 hours had gone from when the glue was put on. Naturally I inspected the joint before tuning and after, and there were absolutely no changes. And there was NO sag! (Hooray!)
I discovered that the bridge now didn´t fit very well, but that was just to be expected. There´s a good thread in this section about bridge-fitting, and some methods are mentioned that I haven´t heard of before. The sanding-method always left me with those little gaps on the edges of the feet, and I never got a really good result that way.
Fitting the bridge properly will be my next little project.

I´ll keep an eye on that brace in the future, and should it loosen again, I´d be pretty sure that it´s because of the glue. I could give it a go with Titebond then.

Thanks to everyone for posting and giving advices, you are all part of my humble succes!
And I really love all the great ideas of remote controlled jacks, balloons etc. They´re planting seeds and may very well help in develloping new methods for brace-fixing.

Søren

[sunburst]

Congratulations, Soren! (Sorry, I don't know how to type that letter.)
Having cleaned the old glue out, it should stay glued.

Part of learning repairs is "learning to think" like a repiarman. Ideas can come from anywhere, so I'll ask anybody for ideas.
A friend of mine was having a problem figuring out how to do something with a problem banjo fingerboard. He was talking to his mother and mentioned the problem. She has no repair experience, but she came up with a great idea that worked.