Easiest way to remove broken bridge

So, here's the deal -

I found this tenor sized uke at a garage sale last weekend and picked it up for $5. It doesn't have a label or headstock logo or anything, but the top has the Hawaiian islands cut out as the soundholes. If I were to guess, I would bet dollars to doughnuts that this is one of those Vietnames ukes for sale on ebay.

I think it's solid wood based on the fact that the grain pattern I can see inside the body matches the outside. From what I can see there are no cracks or splits or loosening of the body, neck, fretboard, etc. There is a near 1/2" gouge on the finish beneath the bridge.

The big problem is that the front-edge of the bridge, that keeps the saddle in place, is cracked off, meaning the bridge will need to be replaced. (see pics)



I called some local luthiers about this and one (Boulevard Music in Culver City) was helpful, but reckoned it would cost about $100 to replace. I also called McCabe's but the guy was kind of a jerk and seemed upset that I was bothering him about fixing a garage-sale uke. He said about $300 (I think just to get rid of me more than anything else). Anyway, I figure for a $5 investment this might be a nice way for me to try my hand at a DIY project.

So, the first step: what's the best recommended way to remove the bridge? I've read that masking off the bridge then using a warmed thin-bladed knife or wedge to pry it off. Would a 1" putty knife suffice? Also, the bridge itself is glued on super tight, with no separation at any part from the body. Would a heated knife still get me underneath that?

All help is greatly appreciated.

If it was me, I'd probably try gluing the broken piece back in place, provided its not smashed to pieces. Use epoxy and wrap the bridge in plastic to keep the slot sized correctly and prevent the epoxy from sticking. Use tape to hold everything in position. Epoxy doesn't need clamp force. If it doesn't work, then you can try getting the bridge off.

Titebond wood glue can be softened with heat but I'm not sure a warm putty knife would do it. Maybe a heat gun and the hot knife?

I tried this technique, but it didn't work all that well

Kayak Jim said:

If it was me, I'd probably try gluing the broken piece back in place, provided its not smashed to pieces. Use epoxy and wrap the bridge in plastic to keep the slot sized correctly and prevent the epoxy from sticking. Use tape to hold everything in position. Epoxy doesn't need clamp force. If it doesn't work, then you can try getting the bridge off.

Titebond wood glue can be softened with heat but I'm not sure a warm putty knife would do it. Maybe a heat gun and the hot knife?

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I may give the epoxy a go, but I am a bit skeptical that it will hold. From what I can tell, the break happened at a point where re-gluing would probably not provide sufficient strength. Still worth a go, anyway.

new wave ukulele said:

I tried this technique, but it didn't work all that well

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On the contrary ... I'd say it worked splendidly. After all, the bridge is off. It's just the top with which you need advice now.

To get the bridge off you will need to apply heat to the bridge itself and not the top. Then also some very careful and judicious use of a pallet knife that may be heated (not red hot or anything that would burn wood) will get the bridge off. I use the water in my glue pot to heat my pallet knife up it.

For the home handyman I recommend making a cardboard mask for the top that will have a hole cut the size of the bridge to allow it to poke through. Cover the cardboard on one side with Al-Foil. Place over top of uke with Al-Foil up and then you could use a hair drier, heat gun, heat lamp or what have you to gently heat the bridge will affording some protection to the rest of the instrument. I've even seen a demo where I guy used a cloths iron place on the bridge. Go gently as you want the heat to have a chance to penetrate the bridge and soften the glue. At 140 degrees F most glues will be quite soft and easy to remove parts. This is when you take the cardboard mask off and gently get to work with the pallet knife. You may need to reheat the bridge two or three times if it's stubborn, or you didn't get the heat down to the glue the first time.

Pay attention to the finish around the bridge. It's really easy to mark it up doing this.

Allen said:

To get the bridge off you will need to apply heat to the bridge itself and not the top. Then also some very careful and judicious use of a pallet knife that may be heated (not red hot or anything that would burn wood) will get the bridge off. I use the water in my glue pot to heat my pallet knife up it.

For the home handyman I recommend making a cardboard mask for the top that will have a hole cut the size of the bridge to allow it to poke through. Cover the cardboard on one side with Al-Foil. Place over top of uke with Al-Foil up and then you could use a hair drier, heat gun, heat lamp or what have you to gently heat the bridge will affording some protection to the rest of the instrument. I've even seen a demo where I guy used a cloths iron place on the bridge. Go gently as you want the heat to have a chance to penetrate the bridge and soften the glue. At 140 degrees F most glues will be quite soft and easy to remove parts. This is when you take the cardboard mask off and gently get to work with the pallet knife. You may need to reheat the bridge two or three times if it's stubborn, or you didn't get the heat down to the glue the first time.

Pay attention to the finish around the bridge. It's really easy to mark it up doing this.

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Much mahaloz, Allen!

That seems like something I could try, and that even someone with very little woodworking experience can do, as long as they are careful.

I wonder, if I have that cardboard/foil mask in place around the bridge, could I use a soldering iron at the base (being careful not to actually touch wood) to help start to loosen the glue at a corner?

Here is a bit of Frank Ford's work at Gryphon....he is the master! Basically....exactly what Allen describes!
http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Bridges/ReglueBr/regluebr1.html

PoiDog said:

I wonder, if I have that cardboard/foil mask in place around the bridge, could I use a soldering iron at the base (being careful not to actually touch wood) to help start to loosen the glue at a corner?

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NoNoNo! This will burn your finish. You need to get the whole bridge hot - I've used a clothes iron on the silk/one dot setting, with a towel between it and the bridge. 10-20 minutes gently heating, as Allen said, then gently to work with your blade.

RyanMFT said:

Here is a bit of Frank Ford's work at Gryphon....he is the master! Basically....exactly what Allen describes!
http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Bridges/ReglueBr/regluebr1.html

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Perfect! With the advice here, I may be able to tackle this. And thanks for the emphatic warning, Prof ... I will keep the soldering iron far away.

Again, mahalo to everyone. I'll try and document my little project and share if anyone is interested.

i would try to glue just the broken piece back on. I did this with a uke I had with the same break and it held fine, with Titebond. a lot of force is downward on the saddle, i think. but I am no luthier. what do you have to lose though?

I used one of these to heat the bridge, then slid a very thin knife under the bridge and it popped off with no splintering, etc. It's a covering iron for the model airplane builder, ~ $25 at your local hobby shop.

You might use a clothing iron. I don't know if they get hot enough.

140 degrees isn't that hot. Even a heat lamp would work. You need deep penetration, not just scorching the surface.

I'm thinking ahead here, on the assumption that the OP gets this bridge off cleanly. What next?

My guess is to buy a pre-made bridge and glue it on. In which case:

1. Your glue join needs to be bare wood to bare wood. Place the new bridge on the top and scribe round it with a blade. Then scrape away all the glue and finish inside that scribed line with a chisel or razor blade. Do not glue on top of old glue or finish.

2. You will need to clamp the bridge in place while the glue sets. Proper clamps are probably out of budget for this, so you can make your own from pieces of wood/MDF with slots cut out, so they pass through the soundhole (don't forget there are braces inside, so you need a block on the end of the inside leg to clear these. This is crude, but does the job.



3. When clamping the bridge will slide about. I make a dam of masking tape all round where it is to go to stop this happening (about three layers thick). Once it's clamped and the glue starts to set, you can remove the tape and clean up the squeeze out.

The professionals have far better ways of doing this, but for a one-off job you will need to work out your own solution - are there better ideas out there?

First thing I would do is to make a replacement bridge to the same string height and string spacing. After that is done, I would take a nice sharp chisel and cut most of the old bridge off until there was nothing left but a paper thin piece of old wood remaining. Heat that up with where means you have and remove the remaining piece. Clean up and attach the new bridge. If this sounds too hard for you to do, then don't.

Attempting to repair the old bridge by gluing the old piece back on is a complete waste of time IMO. The action looks to be quite high so gluing this thing back together is just trouble down the road.

Try this method from Timbuck http://www.ukuleleunderground.com/f...cing-a-Soprano-Bridge&highlight=remove+bridge

Twitch said:

Try this method from Timbuck http://www.ukuleleunderground.com/f...cing-a-Soprano-Bridge&highlight=remove+bridge

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I like this suggestion. I think I am going to give this a try, only substituting either an iron set on the lowest level or a heatlamp in place of that "biggish soldering iron" Timbuck used.

As far as the replacement bridge, I figure I'll just grab one of those pre-fab bridges online and use that. I think I can find the right size for my uke. As far as glue, I think I'll just use Titebond Hide Glue, since that may be easier for me to get than having to try and find some HHG in a small volume.

Once again, big mahaloz to everyone for pointing me in the right direction. This will be my very first ever DIY project on an instrument, but considering the low level of my initial investment, I won't be too nervous about messing up. Besides, we learn by doing, right?

Titebond liquid hide glue has a bad reputation among instrument makers, for setting rubbery and allowing creep. Not good if your bridge gradually slides into the soundhole. Titebond I is far better.

If you're prepared to spend a little time in practice, household gelatine is a form of hide glue. Simply mix a teaspoonful with about 2 teaspoons of water and heat gently until it is a little cooler than a cup of tea/coffee. The difficulty you have is that it gels even faster than hot hide glue as it cools, so you have only 30 seconds or so to get your bridge in place and clamped - this must be done before it gels, otherwise the joint is poor and won't hold.

I've done this, before I bought conventional hide glue, and the way I'd proceed is as follows:

1. Make sure the surfaces to be joined meet really closely - nice smooth surfaces (sanding).

2. Make a dam of masking tape on the top so the bridge can only sit in the right location.

3. Practice clamping - a few heavy books on top of the bridge will do this (slide the saddle out first to give a flat surface for the books to sit on) if you work out a way to stop them sliding off. I'd say 5-600 pages worth.

4. Practice putting the bridge in place and placing your weight on top, until you can reliably do this in 30 seconds. Remember to put the bridge on the right way round!

Now you are ready. Put the bridge in a warm oven (100C/200F) for 10 minutes. Make up your glue and keep it warm. Heat the top with a hair drier until it feels warm to the touch. And, GO!

I got this (though not the books as clamps) from Frank Ford's site Frets.com.


[Edit: Once the glue squeeze-out turns rubbery, but without disturbing your weights, gently scrape away the excess glue. You can clean up further with a cotton bud dipped in hot water and then squeezed almost dry - keep washing the glue out of it. Don't dribble water round the joint.]

One way to keep the bridge in the position you want is to drill two 1/16 inch holes in your saddle slot right through your soundboard and put two " L " shaped wires in the holes to keep it from moving. Once there is a layer of glue
under the bridge it will move around if you are not careful. The holes are also handy if you want to electrify.

I would try to glue back the broken piece with epoxy first, then glue another thin "wall" on the broken side of the bridge to enhance the strength. Basically, it will thicken the bridge wall a bit and makes it stronger (hopefully). This is much easier than removing the bridge which is the last resort.