Help me fix a neck

[JohnH]

Could I please have a little advice from the woodchucks on the forum?

I’ve been asked if I can fix a bass guitar, belonging to the son of a neighbour, which got stepped on and so has a broken neck (note to neighbours son: On floor next to bed = BAD place to put music gear)

It’s not an expensive bass, and the advice from a repair shop is that it is not worth repairing. That may be true from a cost point of view, but I think it is very reparable, at least to a playable condition.

The bass has a maple neck and rosewood board, the break is about 2” down from the nut, and is clean and straight at a fairly acute scarfe angle to the neck. The board is undamaged and remains attached to the lower length of the neck, creating a clean ‘birds mouth’ opening between board and maple neck, while the headstock and first few inches of neck is now a separate piece that will fit into the ‘mouth’. There may even have been a joint there before. (EDIt - yes there definately was an old joint there, with a change in the grain)

So question – what sort of glue is best? White PVA wood glue would be easiest, but I’m thinking an epoxy might be better? Or something else? I’ll be able to clamp the joint effectively while it sets.

Also, the truss rod seems to be hanging out there, and I can't see how it was engaged onto anything. What was supposed to anchor it?

Here's a photo:



With thanks

John

[ux4484]

Wow....First thing I wanted to do when I saw that pic was smack someone (the kid) in the back of the head. It's an accident when you trip and drop your axe, or when a strap or peg breaks, but this one was completely avoidable. You're too good John, I would have told them to get thee to musicians friend.

That said.... Seeing that it looks like a glue joint already, I'd say it's do-able. I'd go with Gorilla wood glue, it's great for clean breaks like that, and dries to a color not far off from the neck.

On the truss rod, I'm sure a quick google would do wonders, but I always thought a truss rod was slightly bent so that when you turned it inside the pocket it just put counter pressure on the wood and is only attached at the end where you adjust it from.

[D2o]

Hi John,

It sounds like ux4884 is on to something there.

I thought I'd pipe in - not because I've fixed guitars before, but because my sister-in-law just happened to email a few pictures last night from a tour she took through a local luthier's workshop. Your 50hz must have meshed with my 60hz or something, because I was zooming in on the guy's workbench tools and various adhesives before you even posted last night. Weird.

For the record, he has a LOT of LePage's Carpenter's Glue in his shop. Still, I would tend to want to go with ux's thoughts - if Gorilla Glue is as good as it's supposed to be, that oughtta do the job well.

I also googled "luthier's glue" after I saw your post last night and came across this, which is sort of along the same lines as ux's thoughts, and sounds like either a well educated and experienced opinion or one smokin' good lie.

Good luck!

P.S. Sorry - not a clue about the lonesome truss rod. Sounds like it must not have been doing a whole lot?

www.thegearpage.net/board/archive/index.php/t-87702.html

John Phillips

06-17-2005, 03:13 PM

I use epoxy (the slow set, maximum strength type - the quick-set is not suitable at all), heated gently with a hairdryer until it's very thin, which makes it penetrate into any cracks and soak into the wood much better, as well as speeding up the setting - and actually increases the strength when hardened too. I heat the wood both before and especially after applying the glue and clamping, it's the key to making it work properly IMO.

It's not a traditional luthier's glue for sure, but I use it because it's extremely strong, and totally immune from creep, solvents, and the effects of heat (at any temperature that won't damage a guitar in other ways, anyway)... ie it's permanent. The usual caveat applies - it is not a suitable glue to use if you may ever want to get something apart again, or aren't certain of getting the repair absolutely right first go. But I do like it for headstock repairs because it's absolutely rock-solid once it's set.

[RJB]

Can't see from that view, but if the truss rod attachment point hasn't been compromised (reference here) you should just be able to glue away.

As far as glue I've read in some woodworker journals some studies that say basic yellow wood glue is as good as anything short of epoxies. Urethane glues (Gorilla) are no stronger, just waterproof. YMMV

[lpf3]

John-

At least it 's a lucky break , no blobs of glue or splinters to interfere with your work .

It's the other end of the truss rod that holds it in place - you'll want to keep the glue off that truss rod nut . I'd loosen it - that way you can turn it a little ( to keep it free ) as the glue is setting without putting any tension on it . Also put something like Vaseline on it so glue won't stick , just be careful to keep it off the wood .

Gorilla glue is excellent , so are the yellow glues like Titebond or Roo Glue . I'd prefer them over the white glue -- I don't know about epoxy .

A couple of suggestions -
coat both pieces with glue & give it a little time ( several seconds ) to penetrate , that way you'll be sure you're not squeezin' it all out before it can do any good .
Because you're clamping at an angle , the pieces may want to creep along the glue line - for me it's easier to use a couple of small bar clamps , the kind that use a trigger to ratchet down , rather than " C " clamps that screw down - sometimes turning the screws on these clamps helps cause this creeping . So does going too tight - keep an eye on this .
Wipe off as much excess glue with a damp rag ( before it sets ) as you can for obvious reasons .

AS far as Ux's suggestion about smackin' the kid in the head , a true bass player may not notice that - ya may have to get his attention another way ;D

Good luck ( you won't need it )



-lpf3

[JohnH]

Thanks very much for the replies. I think I'll probably go for the epoxy - it appeals to my sense of structural engineering.

cheers

John

[crazymanandy]

Epoxy is great, especially if you're trying to fill gaps. It's very permanent though (don't screw up ). If you were to use any other glue, Titebond Original is your best bet. Proven, oft used wood glue for instrument use.

CMA

[JohnH]

OK dunnit!



I used Bostik 'Epoxy Bond Super Strength', which seemed to give me about 20 minutes of workability, and as I type his, after 40 minutes, the remainder is definitely firming up.

Advice on creep along the glue line and getting end to end clamping was appreciated, since although my dry-run with the three clamps looked fine, once it was all lubed up with wet epoxy it was as slippery as a wet fish. a couple of the strings were pressed back into service to stop the head squirting off across the room.

So, how long do you think I should leave it before unclamping?, and before stringing it back up?

cheers

John

[lpf3]

a couple of the strings were pressed back into service to stop the head squirting off across the room

What a good idea ! I'll have to remember that one

So, how long do you think I should leave it before unclamping?, and before stringing it back up?

If that was "regular" glue , I'd say overnight , period . Epoxy ? I don't know , altho' overnight can't hurt .....

BTW - a while back I overheard a repairman in my area quote a customer $ 40.00 for that very repair & it seems to me that anything that plays is worth 40 bucks . Maybe the guy you talked to just didn't want to tackle it ....

Nice job .



-lpf3

[JohnH]

Just to complete the story, heres the finished result, which I think is better than I'd expected:



The clamps came off after about 14 hours, and I was able to scrape and lightly sand away the hardened epoxy that had squeezed out of the joints. It was lucky it was an unfinished neck. Its smooth now and you can't feel the repair. About 20 hours after glueing, I put the strings back on and plugged into my guitar stack....

doom...doom...doom... it plays fine

So it wasnt too hard at all, but if I had to make a living doing this, I'd need to charge alot more than $40.

John

[D2o]

Jun 29, 2008 2:15:41 GMT -5 JohnH said:

Just to complete the story, heres the finished result, which I think is better than I'd expected

John, +1

I knew you were an ace with electronics. Now you can add luthier to your credentials. Soon we'll be calling you "Tinker Jones"!

Did you do any fancy heating of the epoxy or anything like that, or just use it "as is"?

[JohnH]

thanks DD

The epoxy was straight from the tube and mixed. It's winter here, so I had a fan heater to keep the room warm, and kept a desk light low over the work to warm it up slightly while I was working, and also while it set.

cheers

John

[andrew]

that was actually the join in the neck......
if you look at ibanez guitars.... some of them have it too
...
i am asuming the company manufacture it so that under stress the neck seperates there.. and not into splinters or split the neck...
good ide really since ibanez guitars are main choice of metal guitarists....

should have used white glue on it in my experience and opinion....
epoxy tends to seperate under stress (as i found out when i tried it once on an acoustic bridge)
it doesnt pop right off.... it slowly lets go... rubbery lol

keep an eye on it

[JohnH]

Andrew, thanks for your comment, but I'm not too worried. My day job is structural engineering, and in construction, epoxy is usually first choice when an adhesive with a permanent long-term bond under high load is needed.

John

[angelodp]

Looks awesome, so educate us, as either hyde glue or tite bond white glue is the normal first choice. How does the epoxy interact at a molecular level to create a lasting and solid bond??

best Ange

[kuzi16]

funny that this thread should pop up right now. A co worker has just asked me to do almost the exact same repair. I was actually logging in to see if i could find this. HA!