Kala Ukedelic: Popped Bridge needs reglued

Kala TREG Tenor (laminate): bridge popped off.

Result: relatively clean break. Seems like only the center 2/3 was glued to wood, outer ends glued over paint. Most of glue remained on body, seems very slightly tacky. There is a support block underneath the soundboard, under the bridge area.

Questions:

1. What kind of glue or adhesive was used for this Kala, and why does it remain very slightly tacky?

2. Should this residual glue be removed? How about the painted surfaces under the ends of the bridge?

3. Any issues using epoxy? Or is another glue preferable (something I can buy at Home Depot or Lowes?)

Plan so far: Since I'm able to place the bridge accurately now, I plan to do so, then drill two positioning holes through the bridge, soundboard and support block. Then run tape around bridge to protect surrounding area. Remove and lightly sand the bottom of the bridge, try to remove glue, carefully sand soundboard. Then apply glue/epoxy, replace accurately (by tape edges and positioning holes). Either clamp very carefully (protecting back of uke) and/or use small screws through positioning holes, affixing to support block.

Speaking as a rank amateur, competent advice more than welcomed.

Thanks...

Did you contact where you bought this? I would think it might be covered by warranty

Yup, it was under warranty, and is being replaced, but it worked out that I was able to buy and keep this one (at a very low price) as a fun repair and set-up project. Thanks for posting.

Are they replacing it for free? I'd like that kind of deal!

Go to www.frets.com for advice on glueing bridges. Go to the Big Index Page, and scroll down until you find it. I'd scrape rather than sand the glue to remove it. Epoxy isn't used for bridges as far as I know. Titebond and hide glue seem to be the most common, and Rick Turner uses CA adhesive for some of his guitars. You do want to remove all of the old adhesive from both parts, as glue-to-glue doesn't last long.

Kayouker said:

a fun repair and set-up project.

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Cool! Glad it worked out.

Post us some pics of the repair!

FrankB said:

Epoxy isn't used for bridges as far as I know. Titebond and hide glue seem to be the most common, and Rick Turner uses CA adhesive for some of his guitars. You do want to remove all of the old adhesive from both parts, as glue-to-glue doesn't last long.

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Good advice, thanks. But I still wonder - what kind of glue do you think Kala uses? It's still very slightly tacky and not completely hard and dry, has a little bit of "give" to a fingernail.

Sounds to me like that bridge has come off before you bought the uke..and some one has done a poor DIY repair job with wrong type glue.

Timbuck said:

Sounds to me like that bridge has come off before you bought the uke..and some one has done a poor DIY repair job with wrong type glue.

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From the photo, it doesn't even look like the original bridge! Did you buy this new?

stevepetergal said:

From the photo, it doesn't even look like the original bridge! Did you buy this new?

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Yup, brand new, factory warranty (which was honored). I understand that it's not uncommon for the glue to be placed only under the raised center bridge - wood to wood - but over paint on the ends or perimeter of the thinner sub platform (miinimizes the issue of paint ending at the edges).

My only question now is whether any luthier or knowledgable person knows what kind of glue/adhesive Kala uses. This is the original bridge on a new instrument.

Thanks for all your replies.

I don't think anyone here is necessarily going to be able to answer the question what glue Kala uses because I believe Kala subcontracts most of their production, at least of laminated ukes, to a number of "lowest bidders." Your description of the slightly tacky glue leads me to believe it could be either contact cement that did not properly cure (usually due to age or exposure to contaminants) or epoxy that was not properly mixed or didn't cure for other reasons (again, usually age or exposure to contaminants).

However, almost any glue can end up never curing properly for much the same reasons.

The bottom line is that it doesn't matter too much what type of glue it is adding more glue, even of the same type, on top of the tacky improperly cured glue is not going to give a strong bond. You have to get whatever is on there off, completely. I would start with acetone as it will remove many types of adhesive. Sanding the glue off is also an option.

I would get as much of the tacky glue off as you can, then use a good, fresh glue in a thin layer. Clamp it and let it cure thoroughly. Then, I'd drill through the bridge and string it through the top so there is as little strain on the bond as possible.

EDIT: Okay...just noticed the thumbnail of the pic in your post. That doesn't look like residue from either contact cement or epoxy. That white residue could be "water cured" superglue. Some Asian outfits use gel super glue and spray it with a water mist to make it set faster - it often has that characteristic white residue. I've never seen this on a uke, but we used to see it all the time on Ready-to-Fly RC airplanes that were built from kits by Asian companies.

Super glue when it is old and has been exposed to air often remains tacky and never sets up (even when sprayed with water) and especially if it has been applied too thickly.

None of this changes my original recommendation - get the residue off and then glue the bridge down with fresh epoxy or what have you and string through the top. Assuming, of course, that you want to put that much effort into this.

John

Kayouker said:

Yup, brand new, factory warranty (which was honored). I understand that it's not uncommon for the glue to be placed only under the raised center bridge - wood to wood - but over paint on the ends or perimeter of the thinner sub platform (miinimizes the issue of paint ending at the edges).

My only question now is whether any luthier or knowledgable person knows what kind of glue/adhesive Kala uses. This is the original bridge on a new instrument.

Thanks for all your replies.

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It doesn't matter what glue Kala used, it obviously didn't work well and dried wood glue should never be sticky. Scape all the paint off the wings of the bridge footprint area, leaving only about 1/32" of paint left all around the bridge footprint. Make sure it is wood to wood, no leftover glue spots. Use Titebond red cap, spread a thin layer of glue to both surfaces, clamp or weigh down the bridge for 24 hours, clean up any glue squezze out while the glue is wet. You should be good to go.

Here's a quick tutorial on reattaching a bridge. Carefully scrape down the area of the uke where the bridge was attached until you reach bare wood. Don't gouge or remove the wood itself, and be very careful around the edges so as not to mar the paint. If you want, you could leave 1/32nd or 1/16 of the edge more or less unscraped, provided there isn't a mound of glue that would prevent the bridge from making good contact with the body. Then scrape the bottom of the bridge down to wood, too. You could use a utility razor, the kind you might scrape paint off of glass after painting a window frame, to do the scraping, just hold it between 30 and 45 degrees leaning towards or away from you and scrape in that direction. A very sharp chisel could be used, too, but chances of gouging go up with such a tool. Once you've scraped it, clean off any dust etc., so you have clean surfaces to glue together. You could use a lint free rag and a little rubbing alcohol, if that's what you have--shouldn't affect the surrounding finish if you get a little on it, but be careful anyway. Water will tend to raise the grain of wood, making it necessary to scrape it flat again. Naphtha is even better than rubbing alcohol, but fewer people have it laying around the house. Now go to lowes or harbor freight, or any big box store, and buy a couple of 5 inch deep throat C clamps and some double face tape. Two clamps is good, three's even better. You'll also need some small blocks of wood about the size of the end of the clamps and as tall as the brace inside your uke that's just below the sound hole. Use the double face tape to stick the small blocks of wood onto the c-clamp ends (the side that's stationary, as opposed to the side that actually screws down). Check this graphic out.


This isn't to scale or anything, I just threw it together to illustrate the process. Practice clamping the bridge in place with the braces. You'll have to remove the saddle from the bridge. Put something in between the clamp and the bridge to keep it from marring the bridge. Thin bit of smooth wood would do. When ready, spread a liberal amount of glue (Titebond original--the one with the red cap) on the bridge's underside. You want enough so that some squeezes out when you clamp it down, but just a little should squeeze out, otherwise you could have a right mess on your hands. Clamp and make sure the bridge didn't slide out of position (light pencil marks that extend out a half-inch from the edges of the bridge can help you see what the right position is, as it can be difficult to tell once you've got the bridge on the soundboard). If it's slid around some, loosen the clamps and re-position and try again. If the bridge is positioned incorrectly, the uke won't sound right, so this is important. Once you're satisfied it's in the right position, clamp firmly, but don't overtighten. Those c-clamps can bring a lot of force to bear. Use a thin bit of wood with a square corner to go around the bridge and scrape up the glue that squeezed out, wiping it on a piece of paper towel ever so often as you do, and then go back with a damp piece of paper towel and wipe the area around the bridge down with that. Get another piece of damp paper towel and do it again because the first time you might have just thinned the glue and then spread it around. Damp, not wet, because wet can leech some of the glue out from under the bridge making for a weaker bond and a messier sound board.

Caveat, I'm not a pro, I've just done this a few times, is all.

Lots of great advice, thanks. Matt, thanks for an especially thorough method. As luck would have it, I'd put a double layer of painter's blue tape around the bridge area to protect the finish, and had already scraped/sanded away all the residual paint and glue using - yes - a window scraping blade. Worked great.

I figured out a great way to align the bridge before I sanded away the residual paint and glue. This was the perfect time as that residual allowed me to find the original placement. This made it easy to tape down the bridge in its exact original position, then drill four 1/16" holes through the bridge, the soundboard and through the support bar under that.

These holes will allow perfect alignment when regluing, and I then plan to use 4 brass wood screws to hold it down and btw, add clamping pressure of their own. I will enlarge the holes in the bridge slightly so the screws will pull it down tight. I may not need to clamp it at all this way...

More pics to follow... so far though, this is not a difficult job.

Kayouker said:

Lots of great advice, thanks. Matt, thanks for an especially thorough method. As luck would have it, I'd put a double layer of painter's blue tape around the bridge area to protect the finish, and had already scraped/sanded away all the residual paint and glue using - yes - a window scraping blade. Worked great.

I figured out a great way to align the bridge before I sanded away the residual paint and glue. This was the perfect time as that residual allowed me to find the original placement. This made it easy to tape down the bridge in its exact original position, then drill four 1/16" holes through the bridge, the soundboard and through the support bar under that.

These holes will allow perfect alignment when regluing, and I then plan to use 4 brass wood screws to hold it down and btw, add clamping pressure of their own. I will enlarge the holes in the bridge slightly so the screws will pull it down tight. I may not need to clamp it at all this way...

More pics to follow... so far though, this is not a difficult job.

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Putting screws in the bridge is a really bad idea. You don't need them, the glue will do the job. I can't tell you how many times I have had to remove screws from bridges that people have fixed themselves, and then the bridges fails again. Its your uke, you can puts bolts and nuts on it if you want, but it's not the right thing to do.

You need to scrape off all the old glue and get down to bare wood. Get rid of the paint as well. I think it is tacky due to the glue they used dissolving the paint and reacting with it. I have never seen anyone try to glue to paint. I use tite bond exclusively. With surfaces properly prepared it should never give way. Make sure the underside of the bridge is properly prepared as well.
Regards Garry Petrisic.

Putting screws in the bridge is a really bad idea

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I agree. If you already drilled the holes, fill them with wood dowels instead of the brass screws.

I've done this repair at least 50 times, mostly on cheap guitars. First, understand that adding weight to the bridge will reduce its ability to transfer vibration to the top, so adding screws will change the sound, most likely not for the better. Second, Matt Clara's method is a good way to do it, though I would modify it a little - mainly to keep the top from distorting while you clamp it. First, I would tape a block of wood under the bridge and roughly the size of its footprint, tall enough to get your clamp(s) over the cross brace. If you can get three clamps through the sound hole on a uke use one on each wing and one in the middle to spread your clamping evenly. If, as I suspect, there isn't enough room for that you can do the same thing with one clamp by one of two methods. You can clamp a stiff piece of wood across the bridge and use wedges to apply pressure to the wings or you can clamp a piece with blocks at each end and use wedges to apply pressure to the middle. I would also prepare a piece of wood to go under the c-clamp and across the top to prevent the weight of the c-clamp from twisting the bridge forward.

A greater way to make alignment holes would have been to drill two small holes in the saddle slot down through the top and then put brads there during glueing. Then pull them out. If you tighten those screws you're planning to use you might tear the top - it's hard to screw in such a thin bit of wood (or plywood).

Sven said:

A greater way to make alignment holes would have been to drill two small holes in the saddle slot down through the top and then put brads there during glueing. Then pull them out. If you tighten those screws you're planning to use you might tear the top - it's hard to screw in such a thin bit of wood (or plywood).

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Excellent. I saw the screws as temporary anyway, a temporary aid to alignment, but perhaps also useful as an aid to clamping. To be fair though, this is a laminate that already has a modest support block glued to the inside of the soundboard, under the bridge area. I'd guess no more than 1/8 thick (and that is a guess by feel). This bridge support is a thin ply of some kind.

What I found VERY interesting is that when the glue and paint was removed, the bottom of the bridge showed bare wood - good. However, the sound board when the paint/glue was removed showed what appeared to be a very light yellow - for lack of a better term - maybe a primer of some sort.

Thus, when Kala glued the bridge on, it was over this primer, except for the wings, where the glue was applied over primer and paint. I see no evidence of wood to wood gluing, but rather wood to primer, or wood to primer/paint.

After more sanding I am beginning to see wood grain under the "primer".
Pic below...