Removing a Bridge

[John Reid]

Just discovered on a dreadnaught I finished in spring 2003 the bridge is coming off the top. The gap on the lower bout side was about 0.030”. I looked at my notes I made when gluing it and they said that there wasn’t much squeeze-out on the lower bout side. So, maybe that was the issue?

Watched a bunch of YouTubes to see how people remove bridges and took a go at it. I bought a frosting knife and sharpened the tip. Then I kept heating up the tip of the knife with a heat gun to get it around 200-230 deg and starting slowly working it around the bridge. Tried to be patient and careful.

Anyway, the pictures show the results. The top is western cedar.

Trying to learn something from this.

Is western cedar harder to glue? I remember when building, it seemed more prone to tear out and cracking.

Do you think the results look like the bridge can be reglued, or did I do too much damage to the cedar.

I’d love any input on this.

[Kevin Sjostrand]

Hey John
I've pulled 4 bridges I believe and each on came off pretty clean.
The way I did it was with a knife just like you have there, but I allied heat to the bridge using a damp cloth folded on top if the bridge and a hot clothes iron sitting on top of that, letting the heat work down through the bridge to the top. I have a mini iron I use for this, but one of the I removed was in India and I had to use a full side iron.

I'd think you'll bave to scrape that burned glue off and get to clean wood. Clean both surfaces, reshape the bridge bottom to fit the arch and I think you'll be fine.

I use Titebond on my bridges. earlier on I used the LMI white glue till they no longer sold it.
Any get as good a fit as you can, and use plenty of glue.

[John Reid]

Thanks Kevin. My first bridge removal. A little scary.

I had had some shellac on the top to protect it while working on it before gluing the bridge. I'm wondering if I just didn't sand it off very well before gluing the bridge. And may I didn’t use enough glue, too.

I'll clean everything off.

Is this something I want to get good at? :)

[JLT]

In my limited experience with such things, I think that the damage appears to be limited and you can go ahead and glue the bridge back on. You didn't say what sort of glue you used on the bridge when you built the guitar but, if it was hide glue, I'd fist paint the soundboard with a thinned solution of the glue to let it seep into the cedar top. And then you'd heat the area to soften the glue and stick the bridge back on with a glue of normal thickness.

If you used CA like the LMI white glue, it might be a different story. I'll let others chime in on that.

[MaineGeezer]

Whoever said to apply heat to the top of the bridge...yes, very helpful.
I heat up a chunk of brass about 1" square and 4" long and set it on top of the bridge. The clothes iron would be good because you wouldn't need to keep heating it up again, and again, and again...as it cooled off. You might want to put aluminum foil around the bridge to protect the top finish from the heat from the overhanging iron extending out from the bridge.
My luthier friend Carter removes bridges that are lifting by sticking a heavy knife in the gap and giving it a whack with a hammer. He claims it doesn't do any more damage than heating and all the unsuccessful prying that happens before it comes loose. I don't have sufficient faith in my ability to judge when such an approach is okay and when the bridge is still too stuck to try it.

[John Reid]

Well, it’s done.

I cleaned up the top and the bridge, and sanded both. I shaped the bottom of the bridge to get it flush with the top.

There was one spot with some noticeable tearout on the base side. Maybe 0.015-0.020” deep (didn’t try to measure it). Before applying TBO, I filled the spot with TBO mixed with western cedar sanding dust.

I made sure I got lots of glue in.

It’s clamped. I’ll give it a good two days before I string it up. I suspect I’ll have to make a new saddle, too.

[phavriluk]

I think you're doing just fine.

A note to others: Clean up the top and bridge mating surfaces by scraping, not sanding. Dust compromises joint strength.

I match-sand my bridges to the soundboard and cut a very small rebate in the lower edge of the bridge (.020", .025".) I find it easier to control and remove squeeze-out. And scrape the bridge after sanding.

[Kevin Sjostrand]

Peter
I can't picture in my mind the rebate you're referring to?

[Stray Feathers]

John, your "issue" looked a little dicey to me at first, but it looks like you've done beautiful prep work. I think it will come together fine. As for Peter's "rebate", I wonder if it is something like the method used by a luthier I read years ago. He ran a tiny chamfer around the bottom perimeter of the bridge. It gives the squeezeout someplace to go. I have not tried it, but the more bridges I glue the more I think I will. Bruce W.

[phavriluk]

Peter
I can't picture in my mind the rebate you're referring to?

Give the bottom/side intersections a lick with a sanding block at 45 degrees. Hardly any, but some.