neck repair

woolybass · #1 03-25-2008, 10:43 PM

hello there, I am new to the forum and have a question about aneck repair. I have a bass I just received from overseas with a broken neck about 2.5 to 3 inches from nut. the fingerboard sustained no damage and it appears to be fairly clean break. I have built many electric basses over the years and am wondering what I might be able to do myself to get this functioning so I can start playing.Anybody have any advice?
Thanks, Woolybass

Jake deVilliers · #2 03-26-2008, 02:29 AM

Can you post some pix, here or elsewhere?

woolybass · #3 03-26-2008, 04:40 PM

Jake thanks for your reply. I'm trying to figure out how to send attachments. hope this works.Jeff/private/var/tmp/folders.501/TemporaryItems/com.apple.PhotoBooth-T0x3084b0.tmp.g8JsEC/Photo 22.jpg

Jake deVilliers · #4 03-26-2008, 04:58 PM

Not working Jeff!

Try simply clicking on the address bar of your online photo, wrong click & press 'Copy' , then wrong click in your post and press 'Paste'.

I hope that works for you.

woolybass · #5 03-26-2008, 05:36 PM

Jake,here is pix of broken neck

Jake deVilliers · #6 03-26-2008, 06:09 PM

That looks repairable from the pix but it would always show. I wouldn't necessarily recommend it as a first repair.

jonas · #7 03-27-2008, 11:55 AM

Quote:

Originally Posted by woolybass

Jake,here is pix of broken neck

Looks not so bad. The break should be easy to glue. But I'd consider a reinforcement. Therefore, you must remove the fingerboard, cut/saw/route a groove along the center line of the neck and glue a wooden (or graphite) reinforcement in. Then put back the FB etc ...

1st Bass · #8 03-27-2008, 12:55 PM

Well-- I hate to say so, but that does not look easy to me.

You've got an end grain glue joint, precisely transverse to the tension/bending stresses...looks to me like a guaranteed re-break. I would think only a neck graft could save that.

The carbon-fiber reinforcement would be a huge improvement over any other fix, but still a pretty poor joint design, just thinking of how that is going to fit back together. I would think you would want as long a joint as possible, and as close as possible to being parallel to the stress. That would require a graft-- which is not a real easy task, I think. At least not for a beginner.

I'm kind of curious as to how that happened--usually wood does not break off that cleanly. Did it get slammed in a door or something? Just asking...it is an uncommon type of fracture, to me.

jonas · #9 03-27-2008, 03:08 PM

Quote:

Originally Posted by 1st Bass

Well-- I hate to say so, but that does not look easy to me.

You've got an end grain glue joint, precisely transverse to the tension/bending stresses...looks to me like a guaranteed re-break. I would think only a neck graft could save that.

if the break would have been less rectangular, but more longitudinal (like a neck graft), you would have more surface for the glue to hold everything together, right. Bad luck.

Quote:

The carbon-fiber reinforcement would be a huge improvement over any other fix, but still a pretty poor joint design, just thinking of how that is going to fit back together.

You first glue both neck parts together, and then cut the groove - so where's the problem?
As far as I remember, this kind of break is decribed in Chuck Traeger's book, too.

Quote:

I'm kind of curious as to how that happened--usually wood does not break off that cleanly. Did it get slammed in a door or something? Just asking...it is an uncommon type of fracture, to me.

I had the same break (but more longitudinal) with a cello some weeks ago. Someone has put something (or better: wedged something) onto the shipping carton during transportation, and the cello's neck didn't stand the pressure.

1st Bass · #10 03-27-2008, 03:43 PM

Well-- maybe there isn't one-- if the glue holding the carbon fiber in place is enough to withstand ALL the stress of the strings, etc. I just think the butt-joint formed by the two broken halves will not add any significant strength to the overall joint.

You could test it ahead of time, I suppose--glue two 60 mm x 30mm section of wood together, end to end, and then install carbon fiber reinforcements. When it is dry, stress the joint, and see how it responds.

The other issue is that it is very close to the nut, so there is not a long overlap of the FB to reinforce it.

I could easily be mistaken, but my instinct tells me that this break needs a graft, to be a sound neck again. I wish one of the "big boys" would speak up-- Jeff? Bob? Arnold? Ken?

Bob Branstetter · #11 03-27-2008, 04:27 PM

Quote:

Originally Posted by 1st Bass

I could easily be mistaken, but my instinct tells me that this break needs a graft, to be a sound neck again.

If this instrument were to come into my shop, I would recommend either a (new machine carved) replacement neck or a neck graft depending on the quality of the instrument. If neither of these options was acceptable to the customer, I would suggest they take it to another shop.

jonas · #12 03-27-2008, 05:07 PM

Quote:

Originally Posted by Bob Branstetter

If this instrument were to come into my shop, I would recommend either a (new machine carved) replacement neck or a neck graft depending on the quality of the instrument. If neither of these options was acceptable to the customer, I would suggest they take it to another shop.

But woolybass considers to do the repair himself. Since the the neck is already broken, he has nothing to loose, but he might get some repair experience. The worst thing that may happen is that the neck (the repair) brakes again (hopefully not live on stage

)

jonas · #13 03-27-2008, 05:18 PM

Quote:

Originally Posted by 1st Bass

Well-- maybe there isn't one-- if the glue holding the carbon fiber in place is enough to withstand ALL the stress of the strings, etc. I just think the butt-joint formed by the two broken halves will not add any significant strength to the overall joint.

ok, I wasn't precise. I meant: where's the problem to get it aligned if you fisrt glue and then cut the groove.

Bob Branstetter · #14 03-27-2008, 05:48 PM

Quote:

Originally Posted by jonas

The worst thing that may happen is that the neck (the repair) brakes again (hopefully not live on stage

)

Unless his thumb happens to be on the joint when it lets go (ouch!).

**Matthew Tucker** · #15 03-27-2008, 09:12 PM

You could use graphite fibre, but that's usually a fairly small insert. I think you might be better off to carefully route a larger channel down the center of the neck, say 10mm deep and 20mm wide and inlay a larger diameter straight grained hardwood fillet into the slot (I think Jonas suggested this before). This would increase the glue surface AND increase the amount of contiguous longitudinal grain running through the repair right up and under the nut. It would replace a large amount of the curly wood in the region with strong wood, but leave the exterior flame intact. it is definitely a two stage operation, glue it together in situ then remove FB for the insert and re-glue. I wouldn't use CF for this, I would go for nice strong straight maple.

But probably less fussing about than a full scroll graft. Depends quite a lot on what the bass is worth, I thing. Is the scroll worth saving?

jonas · #16 03-28-2008, 05:46 AM

Quote:

Originally Posted by Matthew Tucker

You could use graphite fibre, but that's usually a fairly small insert. I think you might be better off to carefully route a larger channel down the center of the neck, say 10mm deep and 20mm wide and inlay a larger diameter straight grained hardwood fillet into the slot (I think Jonas suggested this before). This would increase the glue surface AND increase the amount of contiguous longitudinal grain running through the repair right up and under the nut. It would replace a large amount of the curly wood in the region with strong wood, but leave the exterior flame intact. it is definitely a two stage operation, glue it together in situ then remove FB for the insert and re-glue. I wouldn't use CF for this, I would go for nice strong straight maple.

that's exactly what I tried to suggest. I have no personal experience with graphite yet, but I've mentioned this as an option because it's sometimes used for neck strengthening nowadays.

1st Bass · #17 03-28-2008, 08:02 AM

I installed a double reinforcement of CF in a bass for a fellow last month. I ripped two slots, at about a 75 degree angle to one another (fanning out from near the centerline) , 9/16" deep, 5/32" wide, and the full length of the neck-- I installed the 1/2" x 1/8" CF rods using epoxy, clamped the neck completely straight (it had a tiny warp in it), and allowed it to set up. I sawed off the excess CF at the heel and inside the pegbox, and sanded them flush (hard stuff-- dulls carving tools instantly), then re-finished to cover. You can tell they are there, but they are not at all obtrusive.

In this case, it was only the reinforcement that was wanted-- there was no break in the neck. Unless there was a particular reason to save THAT neck, Bob's suggestion of a pre-carved neck is a reasonable one, in terms of time, looks, and durability-- you can still install the CF if you want it. If the scroll is what you want to save, then the graft seems reasonable to me.

I have done the wood inlay (replacement...whatever you would call that) that Matthew suggests, and did not find it an easy task to get a really good fit. But that is certainly one way to handle it, if there is a reason to save the handle-portion of the neck.

Woolybass, if you opt for the CF, there is a company online (dragonplate) that carries the 1/2 x 1/8" rods--as I recall, it was about $30 to get two of them, including shipping. They are 24" long, which is more than enough. Or, if you want a pre-carved neck, International Violin Co. carries them. (google them--it was $230 USD last I checked). There are a few places online that show how to graft a scroll, but that is a pretty major job in itself. Depends on how ambitious you feel.

Jonas is right--the Chuck Traeger book covers this sort of thing...good investment, anyway, if you are interested in working on your own bass.

**Matthew Tucker** · #18 03-28-2008, 04:16 PM

LMI sells a bunch of CF products too.

woolybass · #19 04-02-2008, 10:51 PM

You guys are awesome for sharing some much of your time and experience and time.The bass is new it's beautiful but was only about $1,700.I am not too concerned about a line showing as this is my first double.You have all given me a lot to think about and I've enjoyed the interaction. I will definitely look for 'the book' as I am interested in learning all I can about my bass. A graft or a neck replacement are a little ambitious for now but I like the idea of a graft.A local shop mentioned something about a bolt but that doesn't sound like a very suitable way to go for this type of instrument.
Thanks,Woolybass

woolybass · #20 04-02-2008, 10:59 PM

As to the question of how it happened, it was being shipped from overseas suspended in a carton with a wood frame inside for strength with a soft case rolled up next to the neck. Not around the bass but next to it? and the carton was on it's side with a strap holding the neck about an inch below the break. Sweet, huh? So there you have it.Again many thanks
Woolybass