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I am going to Ervin's course in a week and a half and bringing a guitar to be critiqued. It has been strung up for 3 months, and this morning it developed a crack in the bridge. The crack starts at the edge of the saddle slot on the low e and runs out about an inch. With the strings off the crack closes up quite cleanly but has left the saddle a tiny bit loose.

Is it legitimate to repair this with CA or does the bridge need to be replaced? I' a little wary of removing the bridge at this point - if I screw something up while doing that I won't have time to fix anything else.

Is the saddle height the likely cause? In inches the bridge peak height is .38, with a saddle slot varying from .2-.15, leaving .18 of wood under the slot. The saddle is a little high, about .21. This is about .06 more than I aim for but I wasn't expecting that to cause this type of problem.

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David White, Toronto

"All my favourite singers can't sing."

I'm sure more experienecd people will chime in, but I just wanted you to know that I feel your pain. If the bridge closes after you loosen strings why not try it first, what do you have to loose except the time it takes to glue the crack and/or the bridge back down. Clinton

You could certainly glue it up with CA, but I would definitely route the slot a good deal deeper. If the bridge is 3/8" and the saddle is .21" above, I would route the slot to 1/4" depth. Sounds like you have a really steep neck angle there. A .325" bridge with .120"-.150" saddle is the target range I'm more comfortable with.

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Eschew obfuscation, espouse elucidation.

This is my first post, but I've been lurking for a while now.
Most of my experience comes from a repair background, and I've just started to do a bit of building. I've found that a crack in the bridge probably won't hold if you just glue and clamp. I've fixed a few of these by routing out the affected area(s) and inlaying a reinforcement strip of ebony or RW or whatever the bridge was made of.
This is most easily accomplished by removing the bridge and reglueing after the repair is done. It's not as much work or as costly as replacing the damaged bridge. You can also do the repair with the bridge still on the instrument if you rig up a bit of a jig to run a dremel with a router plate through, although the set up, etc. is probably just as much work as removing and regluing the bridge.
Just thought I'd give you my take on the problem.

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Remember, there are no stupid questions, only stupid answers!

Hi - I've only ever had one guitar, a mid-priced 12 string "store guitar", develop a small crack in the bridge. I took it in to a repair place (before I ever thought about building), had it glued and now I can't even find the repair from 5 years ago.

I'd try the glue first, replacement second...


CAL: welcome to the most addictive website on earth.....


Laurie

I'm with glue first, replace second. I've done this successfully on dozens of Martin bridges that all too often had pin holes too small for the bridge pins. The bridges shrink a bit around those plastic pins; unknowing guitarists wedge them in too tight; they fail to keep the guitar at a decent humidity level; and bingo, cracked bridge.

If you glue, don't try to sand/polish the bridge to much; that will make the glue line more obvious. Take it to 180 or 220 or so.

Cracking like this is why rift sawn wood is really best for guitar bridges. Arrange the grain thusly:

Peghead.........neck............body..............\\\\\\.............tail


That grain orientation gives the least possibility of the bridge cracking. It also reveals nice figure.

Thanks for the comments.

For the record, the bridge is rift sawn, and oriented as Rick suggested.

It seems that glue has a reasonable chance of success so I glued it up which was easy and is pretty well invisible. I am guessing the high saddle is at least a contributing factor so I also removed the neck and will lower the angle to bring the saddle back down to .12-.15.

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David White, Toronto

"All my favourite singers can't sing."

Of course you realize that unless you are adding shims toward the back of the heel to affect a lower neck angle, you will be moving the fret board toward the bridge. Aside from looking a bit off if the 14th (or 12th) fret moves too far in from the body joint, this means you will have to move your saddle back as well.

Increasing the neck angle is easy, decreasing it is not so. This is one of the less common cases where I would have recommended re-leveling the board to change the neck angle, rather than re-carving the heel.

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Eschew obfuscation, espouse elucidation.

Thanks for pointing that out David, yes I had thought of that. The string contacts are a little forward on a 1/8th saddle so I figure I have 1/32nd or 3/64ths so to play with. If I screw up then routing a 3/16th saddle is probably the best fix.

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David White, Toronto

"All my favourite singers can't sing."

...I'm not sure what the math is but I believe to get a 1/16 drop in the saddle you would need to move much less than 1/16th at the neck.

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David White, Toronto

"All my favourite singers can't sing."