Double Bass Repair broken neck on upright bass

[eh_train]

Get some JB Weld 5 minute epoxy ... Edit: I'm referring to the clear stuff with almost 4000# strength.

I'd like to recommend System 3, G2 Epoxy. When wet, it's water soluble so that you can clean up any excess quite nicely.

Let the flames begin.

Nope, not when the customer can't afford a new neck or a scroll graft. I'm doing a similar repair to AVW just now. The bill, with two carbon fibre rods through the break in the neck, will probably be $500 Canadian ($375-ish USD). A new neck or scroll graft would be $2k +.

 

[Greg Clinkingbeard]

I'd like to recommend System 3, G2 Epoxy. When wet, it's water soluble so that you can clean up any excess quite nicely.



Nope, not when the customer can't afford a new neck or a scroll graft. I'm doing a similar repair to AVW just now. The bill, with two carbon fibre rods through the break in the neck, will probably be $500 Canadian ($375-ish USD). A new neck or scroll graft would be $2k +

When considering repair methods, including adhesives there are many choices. Regardless of 'better' choices, the epoxy I recommended is inexpensive and readily available. It is alcohol soluble which won't be a problem with the lacquer on an Engie, although there won't be much time to clean up. I used to be a 'hide glue or nothing' guy until a friend who does a lot of school repairs recommended the JB Weld. I used it to replace a scroll/pegbox and it's still together to my knowledge. It's not my first choice but will do the job.

 

[notabene]

I'm no expert, but that seems realistic. And likely.

Find a way to add whatever wood would fit well physically tight every where, , and use hot Hide glue (not from a bottle, but made from "flakes", and you will, with care have a "better than new " bass. And if you screw it up, there's always a new day!

 

[Aaron Van Wyk]

I'd like to recommend System 3, G2 Epoxy. When wet, it's water soluble so that you can clean up any excess quite nicely.



Nope, not when the customer can't afford a new neck or a scroll graft. I'm doing a similar repair to AVW just now. The bill, with two carbon fibre rods through the break in the neck, will probably be $500 Canadian ($375-ish USD). A new neck or scroll graft would be $2k +.

Thanks for the recommendations. Any reason for G2 over T88? I'm not opposed to using hide glue - I have real hide glue and know how to use it. The only thing is that I don't think simply gluing this joint will be strong enough, even if done very well. So if I'm going to insert carbon fiber reinforcement, it seems that I might as well just use epoxy for the entire repair.

 

[BPM Strings]

G2 is supposed to stay flexible enough to accommodate wood movement. I don't know if it's actual better than t88. I would use hide glue myself, but to each his own.

I think you are on the right track with using carbon fiber rods, but I don't think they will provide adequate reinforcement because your break is so close to the nut. I would use a spline. After removing the fingerboard and glueing the neck back together, make a plunge cut with a circular saw blade (skill saw, table saw, miter saw) in the center of the neck thru the middle of the break. Then make a wooden disk the diameter of your blade and the thickness of it's kerf and glue that into your cut. Trim of anything that sticks out and you're in business. You could even install a cf rod over that.

 

[DJ Bebop]

No, no, no. Do not put metal into the neck joint, first of all. Second, pinning the neck is a subject of some controversy. Many believe that by removing original wood from the neck heel to insert a dowel you end up weakening what is left of the original wood. When the glue eventually fails, you will be left with a weakened neck with a nice fat pivot in the middle of the heel.

Some luthiers have reported success in using three or more chopsticks as pins, as the wood is strong, fibrous and flexible. In any case, to pin the neck heel properly the fingerboard will have to come off. If that is a Chinese cheapo, God only knows what kind of glue it's attached with.

Leave the yellow glue on the shelf.

James Condino, who's fixed many neck heel breaks, told me once that strong hide glue applied properly should be enough to hold that break closed. Other folks say that marine epoxy can do the job while others say epoxy's tendency to creep over time means eventual irreversible failure.

Sorry to be Debbie Downer, but that bass may be toast. Is there a bass or violin luthier nearby you could bring it to for an in-person inspection and maybe even some free advice?

"Sorry to be Debbie Downer, but that bass may be toast."

 

[eh_train]

Any reason for G2 over T88? .... So if I'm going to insert carbon fiber reinforcement, it seems that I might as well just use epoxy for the entire repair.

People seem to have read this as "G2 is better than T88" or "G2 is better than JB Weld". It's not a contest. I like the G2 because it cleans up with water when in liquid form. That's enough of a difference for me...

AVW, sure, once you've used some epoxy you might as well go all in. The neck is not supposed to come apart (at least not in the middle of the handle!) and gluing a broken neck handle back together seems to be a last-ditch sort of repair. If it fails, regardless of which methods you've used, a new neck or a neck graft is probably the next step.

Yes, I realize the hide-glue purists will say "you can re-do it", but if it failed once, I think plan B, pr plan C, are up next...

 

[Don Hergert]

I don't know if it would work as well in this particular situation and location, but I know someone who is using CF tubes instead of CF rods, and having a lot of success with them. CF rods can be pretty heavy plus with a tube the glue used to make them stay in place has a way to squeeze out of the way.

Whatever the OP decides to do, I wish luck and good playing!

 

[Greg Clinkingbeard]

I've been told by respected luthiers to always use hide glue because it can be redone, over and over and…….
Hide glue is used for everything in my shop except necks broken at the heel, scroll or like the one in this thread. I've done repairs to the heel and scroll with hide glue and they often fail at some point.
Earlier this month a customer brought me a bass which had the scroll replaced with hide glue and dowels. It failed and he had another shop do it again. It failed very badly and there was significant damage with missing wood. Near total contact of the gluing surface is essential for a bond with hide glue.
Epoxy and a maple dowel looked like the only option and I strung it up the next day. An old time luthier walked into my shop last week and told me 'anybody using epoxy on a bass should be shot'. OK. Fire away.
Another example: I got a nice old German bass from another shop with a neck heel opening up. It had SEVEN screws in the heel; three in the heel and two on each side of the block holding it in. Once I got it apart I glued the heel break with epoxy and ran a large dowel through it with epoxy. The neck is set with hide glue and will probably never be a problem for the new owner. With hide glue I could fix it over and over and over, but I don't want to. I don't want my customer to have to deal with it again.
I've successfully used epoxy on things where hide glue has failed and probably WILL fail at some point. Until I see epoxy fail I will keep using it in these situations. Never on anything like a neck joint, fingerboard or the bass body.

 

[Aaron Van Wyk]

Thanks for all the feedback. I already have some t88 in the shop so will probably use that. I'll document the repair as I go if only as a "this is what not to do!" Does anyone know what finish is on these Engelhardt basses? Is it lacquer? Certainly does not seem like any kind of proper oil or spirit varnish.

 

[dperrott]

I've been told by respected luthiers to always use hide glue because it can be redone, over and over and…….
Hide glue is used for everything in my shop except necks broken at the heel, scroll or like the one in this thread. I've done repairs to the heel and scroll with hide glue and they often fail at some point.
Earlier this month a customer brought me a bass which had the scroll replaced with hide glue and dowels. It failed and he had another shop do it again. It failed very badly and there was significant damage with missing wood. Near total contact of the gluing surface is essential for a bond with hide glue.
Epoxy and a maple dowel looked like the only option and I strung it up the next day. An old time luthier walked into my shop last week and told me 'anybody using epoxy on a bass should be shot'. OK. Fire away.
Another example: I got a nice old German bass from another shop with a neck heel opening up. It had SEVEN screws in the heel; three in the heel and two on each side of the block holding it in. Once I got it apart I glued the heel break with epoxy and ran a large dowel through it with epoxy. The neck is set with hide glue and will probably never be a problem for the new owner. With hide glue I could fix it over and over and over, but I don't want to. I don't want my customer to have to deal with it again.
I've successfully used epoxy on things where hide glue has failed and probably WILL fail at some point. Until I see epoxy fail I will keep using it in these situations. Never on anything like a neck joint, fingerboard or the bass body.

Yea you have to use epoxy for this. I'm with you. I think it is acceptable for neck and scroll breaks. It's down to two choices, epoxy or new neck. Hide glue is the greatest glue in the world but not strong enough for this. Hide glue and dowels will fail. I've repaired those. I find it interesting how working luthiers know this but everyone else will shudder at the thought of using it. Once again its epoxy or a new neck

 

[Greg Clinkingbeard]

Yea you have to use epoxy for this. I'm with you. I think it is acceptable for neck and scroll breaks. It's down to two choices, epoxy or new neck. Hide glue is the greatest glue in the world but not strong enough for this. Hide glue and dowels will fail. I've repaired those. I find it interesting how working luthiers know this but everyone else will shudder at the thought of using it. Once again its epoxy or a new neck

And when hide glue fails it may not fail completely. With a dowel in there the joint may simply open up and you're left with drilling it out or adding another one. Another thing with hide glue people don't think about is the reality of people leaving a bass in a hot car for an hr or two. Under tension, a scroll repair might open up when a seam may not.

 

[Aaron Van Wyk]

Repair underway. A little heat, steam and palette knife and the fingerboard is off nice and clean.

 

[dperrott]

Repair underway. A little heat, steam and palette knife and the fingerboard is off nice and clean.

I would have left the board on. Yea you might get epoxy on the ebony but it makes clamping it easier and less problems then removing the board and getting it back on.

 

[Greg Clinkingbeard]

I would have left the board on. Yea you might get epoxy on the ebony but it makes clamping it easier and less problems then removing the board and getting it back on.

Me too.

 

[dperrott]

Me too.

Well I must be doing something right then!

 

[Aaron Van Wyk]

I would have left the board on. Yea you might get epoxy on the ebony but it makes clamping it easier and less problems then removing the board and getting it back on.

The fingerboard was already about half way off from the fall that broke off the scroll. Would you have just squished in some glue and clamped the bottom of the board to keep it in place?

 

[dperrott]

The fingerboard was already about half way off from the fall that broke off the scroll. Would you have just squished in some glue and clamped the bottom of the board to keep it in place?

yes. It's common practice to just work glue under it and clamp it. The chances of causing more problems is greater when you remove it.

 

[Aaron Van Wyk]

yes. It's common practice to just work glue under it and clamp it. The chances of causing more problems is greater when you remove it.

Fair enough. Once I'm done with the repair I think you'll see why I did it.

 

[dperrott]

Fair enough. Once I'm done with the repair I think you'll see why I did it.

Hope it all goes smoothly!