Old guitar with a bowed neck

Tremoluxer

Strat-O-Master
Gold Supporting Member
Jul 28, 2020
514
Ypsilanti, Michigan
Heat lamps, aka incandescent lightbulbs, are a cheap way to heat a neck. I fixed by bandmate's Paris Swing GG-42 Gypsy Jazz Guitar that was left in a closet facing south, during the whole summer of 2018 -- in a thin-walled mobile home. The whole top/neck joint area had slipped, causing the guitar to be unplayable. A couple of days with a 100-watt lightbulb inside, and clamped to the workbench at each end of the guitar. Then let it cool for 24 hours. Worked like a charm! Better than waiting until the next summer, clamping it up, putting back into the closet for three months, and hoping for the best.

It would be a bit more difficult to contain the heat from a lightbulb when straightening a neck, but certainly doable. I've used compression fretting, as Dan Erlewine shows in the StewMac book, Fret Work -- Step-By-Step. It was an old classical someone gave to me and it had a warped neck. I thought it was a beater so tossed into a corner for 10 years. Then I took a closer look. It was a Salamanca, built in postwar Germany in 1949, had a solid Engelmann Spruce top and was light as a feather. It needed a refret so, the compression method made sense. I ended up selling it in 2019 for $800. One oddity was the non-standard spacing for the tuning machines. The originals were junk, so I used individual classical tuning machines.


05_Paris Swing Repair.jpeg


07_Paris Swing Repair.jpeg


06_Paris Swing Repair.jpeg


A gap at the 14th fret, that was about 5/16", wound up at 1/10" (straight edge sitting on the bridge and nut) -- not too bad! The neck is strong, hard maple with a square profile -- the stiffest neck I've ever seen. The hot closet had no effect on it. My friend uses 10-44 D'Addario Gypsy Jazz strings, so not too much tension on the neck -- even though the scale length is 26.4".


09_Paris Swing Repair.jpeg
 

Dain Bramage

Strat-Talker
Jan 12, 2012
156
Earth
First thing, just to be sure--I can't see the strings well enough to tell, are those nylon strings? This is a classical guitar and should have nylons on it; steel strings will have too much tension and could cause warping.

Some people have had success straightening necks by laying the neck across sawhorses and then using weights to pull the neck straight. If that's not convenient you might try putting a stout board (4x4 maybe) against the fretboard, draw the neck flat against it with ratchet straps. Leave it that way for several days and then re-check to see if it's changed any.

Wherever you bend it to, it will probably spring back the other way a little bit. But obviously if you bend it too far you create a whole new problem.
This is a decent and tried answer, I would only add careful application of a heat gum to the fretboard during the process can loosen the glue and help the process, but I emphasize "careful" and recommend one try this on a less expensive unit, first, keeping some form of hydration in mind as well. I have also seen a master builder use a pizza oven and neck jig he had made; you have really got to want that to come back to life for that much trouble. This begs the overall question; is it worth that (-to you- is part "b" of that Q), and then the idea that experimenting and learning can be fun, disastrous, or both!
 

dirocyn

Most Honored Senior Member
Jan 20, 2018
6,777
Murfreesboro, TN
This is a decent and tried answer, I would only add careful application of a heat gum to the fretboard during the process can loosen the glue and help the process, but I emphasize "careful" and recommend one try this on a less expensive unit, first, keeping some form of hydration in mind as well. I have also seen a master builder use a pizza oven and neck jig he had made; you have really got to want that to come back to life for that much trouble. This begs the overall question; is it worth that (-to you- is part "b" of that Q), and then the idea that experimenting and learning can be fun, disastrous, or both!

I agree, some heat is likely to help.

This is a $10 guitar, there's not much "less expensive" to go.
 

Willmunny

Has a strat
Gold Supporting Member
Jul 22, 2019
2,507
Mcleary Wa
This is a decent and tried answer, I would only add careful application of a heat gum to the fretboard during the process can loosen the glue and help the process, but I emphasize "careful" and recommend one try this on a less expensive unit, first, keeping some form of hydration in mind as well. I have also seen a master builder use a pizza oven and neck jig he had made; you have really got to want that to come back to life for that much trouble. This begs the overall question; is it worth that (-to you- is part "b" of that Q), and then the idea that experimenting and learning can be fun, disastrous, or both!
This is a decent and tried answer, I would only add careful application of a heat gum to the fretboard during the process can loosen the glue and help the process, but I emphasize "careful" and recommend one try this on a less expensive unit, first, keeping some form of hydration in mind as well. I have also seen a master builder use a pizza oven and neck jig he had made; you have really got to want that to come back to life for that much trouble. This begs the overall question; is it worth that (-to you- is part "b" of that Q), and then the idea that experimenting and learning can be fun, disastrous, or both!
The guitar is a 1986 takamine b 126 that I found on offerup for 10 bucks.
I feel like it's a stray animal that I found and want to save. I played it a little with sky high action and that big bow, and it sounds pretty good.
To be fair that classical fretboard seems huge to me lol. I have some low tension strings incoming. We will see how that pans out.
Thanks again to all who replied
 

Willmunny

Has a strat
Gold Supporting Member
Jul 22, 2019
2,507
Mcleary Wa
Sorry g 126
The guitar is a 1986 takamine b 126 that I found on offerup for 10 bucks.
I feel like it's a stray animal that I found and want to save. I played it a little with sky high action and that big bow, and it sounds pretty good.
To be fair that classical fretboard seems huge to me lol. I have some low tension strings incoming. We will see how that pans out.
Thanks again to all who replied
 

Willmunny

Has a strat
Gold Supporting Member
Jul 22, 2019
2,507
Mcleary Wa
FWIW update
I put on some light strings, neck is still bowed more than I prefer but it's ok for now. Action is very high below the 7th fret. I need to do some more sanding on the saddle, about an eighth of an inch 20210823_102713.jpg 20210823_102741.jpg 20210823_102803.jpg
 

CB91710

No GAS shortage here
Double Platinum Supporting Member
Feb 24, 2019
10,851
SoCal
You can only go so far with the saddle due to break angle and height above the soundboard.
But you have to ask if it's worth having the neck reset.
But considering it was $10, it's worth putting some money into it.
 

dirocyn

Most Honored Senior Member
Jan 20, 2018
6,777
Murfreesboro, TN
You can only go so far with the saddle due to break angle and height above the soundboard.
But you have to ask if it's worth having the neck reset.
But considering it was $10, it's worth putting some money into it.

This is true. If you get the saddle too low, it will buzz at the saddle. But I think you can go a little lower than this one is, even on the high and low e strings.

Also, @Willmunny I just noticed that saddle was made for an acoustic, not a classical. This guitar doesn't have a radius, why should the saddle?

What I suggest is slack the strings and pull that saddle out, then re-tune (ballpark) with no saddle in. Take a look at how the strings lie with no saddle in, and the action. From there, decide if you can get away with simply a lower saddle, or whether you want to shave some height off the bridge or do more work on the neck.
 

CB91710

No GAS shortage here
Double Platinum Supporting Member
Feb 24, 2019
10,851
SoCal
This is true. If you get the saddle too low, it will buzz at the saddle. But I think you can go a little lower than this one is, even on the high and low e strings.

Also, @Willmunny I just noticed that saddle was made for an acoustic, not a classical. This guitar doesn't have a radius, why should the saddle?

What I suggest is slack the strings and pull that saddle out, then re-tune (ballpark) with no saddle in. Take a look at how the strings lie with no saddle in, and the action. From there, decide if you can get away with simply a lower saddle, or whether you want to shave some height off the bridge or do more work on the neck.
There are also issues with the tone when the strings are too close to the soundboard.
You really want that at or very close to 1/2"... no lower than 3/8"
 

dirocyn

Most Honored Senior Member
Jan 20, 2018
6,777
Murfreesboro, TN
There are also issues with the tone when the strings are too close to the soundboard.

Yes, absolutely. On a flat-top the saddle rocking forwards & backwards is the primary mechanism that makes the soundboard move. The saddle is a lever--much like working with a short ratchet wrench vs. a breaker bar, the longer the saddle the easier it is for the string to move the soundboard. Shortening the saddle will make a quieter guitar, and there may be some knock-on effects on timbre as well.


You really want that at or very close to 1/2"... no lower than 3/8"

This rule of thumb I'm less familiar with. My #1 classical has 5/8" between the string and soundboard right in front of the bridge. My other classical has 1/2". None of my flat tops has less than 3/8". So I accept 3/8" to 1/2" being the normal range. Also, I suspect you'd have to shave down the bridge (not just the saddle) to get as low as 3/8".
 

CB91710

No GAS shortage here
Double Platinum Supporting Member
Feb 24, 2019
10,851
SoCal
This rule of thumb I'm less familiar with. My #1 classical has 5/8" between the string and soundboard right in front of the bridge. My other classical has 1/2". None of my flat tops has less than 3/8". So I accept 3/8" to 1/2" being the normal range. Also, I suspect you'd have to shave down the bridge (not just the saddle) to get as low as 3/8".
Ya... 3/8" would be the minimum, 1/2" better, but obviously, that doesn't preclude designs with floating bridges such as archtops being much higher.

I've always viewed shaving the bridge material as a last resort and only if it's still not going to end up wanting a neck reset in a couple of years.

Reminds me that I should probably pull my old Sigma 12 string out of storage and check it.
 

3bolt79

Dr. Stratster
Oct 16, 2018
14,309
Oregon
C
You are correct sir, very much like the top image, without strings on it.
Already planning on finding the lowest tension strings as possible
Call Strings by Mail and ask them about what string sets they have in about the 80lbs of tension range. Labella has a few, and they are not expensive. I think the set you’re after is the LaBella 471. But I can’t really remember the set name. That is really low tension.
 

dirocyn

Most Honored Senior Member
Jan 20, 2018
6,777
Murfreesboro, TN
C

Call Strings by Mail and ask them about what string sets they have in about the 80lbs of tension range. Labella has a few, and they are not expensive. I think the set you’re after is the LaBella 471. But I can’t really remember the set name. That is really low tension.

My usual set is D'Addario Pro Arte EJ45, "normal tension" which means 85.85 lbs. EJ43 is light tension, 79.81lbs.

IDK if La Bella has lighter than that--it's possible, but it was a little harder to find string tension info there.
 

3bolt79

Dr. Stratster
Oct 16, 2018
14,309
Oregon
My usual set is D'Addario Pro Arte EJ45, "normal tension" which means 85.85 lbs. EJ43 is light tension, 79.81lbs.

IDK if La Bella has lighter than that--it's possible, but it was a little harder to find string tension info there.

I think that the labella was 78 point something. 2 lbs isn’t going to make much of a difference.
 

Willmunny

Has a strat
Gold Supporting Member
Jul 22, 2019
2,507
Mcleary Wa
I
This is true. If you get the saddle too low, it will buzz at the saddle. But I think you can go a little lower than this one is, even on the high and low e strings.

Also, @Willmunny I just noticed that saddle was made for an acoustic, not a classical. This guitar doesn't have a radius, why should the saddle?

What I suggest is slack the strings and pull that saddle out, then re-tune (ballpark) with no saddle in. Take a look at how the strings lie with no saddle in, and the action. From there, decide if you can get away with simply a lower saddle, or whether you want to shave some height off the bridge or do more work on the neck.
I a
C

Call Strings by Mail and ask them about what string sets they have in about the 80lbs of tension range. Labella has a few, and they are not expensive. I think the set you’re after is the LaBella 471. But I can’t really remember the set name. That is really low tension.
Not sure of the tension but I used these 20210827_090411.jpg it still needs a neck reset, even though some earlier posters said 1/2 inch of action lower on the neck was reasonable. I am still going to lower the saddle a bit as well
I will do the iron method in the near future.
Actually sounds good and plays decent on the 5th fret and higher.
Thanks again for all the feedback
 

3bolt79

Dr. Stratster
Oct 16, 2018
14,309
Oregon
I

I a

Not sure of the tension but I used these View attachment 503510 it still needs a neck reset, even though some earlier posters said 1/2 inch of action lower on the neck was reasonable. I am still going to lower the saddle a bit as well
I will do the iron method in the near future.
Actually sounds good and plays decent on the 5th fret and higher.
Thanks again for all the feedback

79.81 lbs for that set
 


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