Double Bass Replace or repair a doublebass neck that is coming off

[dbassnut]

Hi guys,
My doublebass neck is coming off and I have already shown this to a luthier in Penang.

He said I could either
1. Glue the old neck back in with hide glue.
or
2. Change the neck & fingerboard. (worn some grooves into the existing fingerboard so might as well get it replaced).

I'd like your opinion on which would be better.

 

[dnhbass]

Reglue! Fitting a new neck is a bit of a project. The fingerboard is a separate issue, most likely simply needs to be planed.

 

[Ortsom]

The joint failure looks very clean, without any visible damage. If that is all there is to it, and if the neck is in good condition: clean & re-glue w/ HHG. However, in your first pic it looks like the heel also may have some sort of crack right in the bend (where you would put your thumb). If that is so, your luthier might consider a reinforcement prior to glueing the neck. Or indeed, maybe a replacement neck.

It is also possible that for this instrument a very cost-effective neck+FB combination replacement is available, which may also be why your luthier raised that option. If your current FB needs to be replaced, taking it off also takes time, hence cost money. His cost estimates can guide you.

 

[dbassnut]

My doublebass is still at the luthiers place so keeping my fingers crossed.

And yes, there is crack. The neck snapped off a couple of years back when I just got it & my orchestra conductor helped me to glue the neck back on.
Also, if you looked closely, there actually 4 lines there. According to my luthier, my existing neck was a cheap one when they glued on 3 additional 1inch pieces of wood to make up the neck heel instead of making the whole neck from a single piece of wood.

Anyone have any idea what the correct angle of the neck should be in relation to the double bass top when viewed from the side?

Thanks,

 

[Ortsom]

I'm not entirely certain what I saw, but I think I saw the built-up heel & artistic purfling in a ply back. Because of that & because of the wood seen, I raised the option of a cost-effective replacement combo. Is this an Indonesian instrument?

Btw, a built-up heel is more a monetary rather than a technical issue.

Now that the heel is out, I'd probably place a reinforcement across the old break, scrape the FB as required & re-glue the heel. That seems cheapest, but I might be wrong. Once again: your luthiers cost estimates should guide you. Fitting a new heel takes time too.

The strings often make an angle between 11.5° & 13.5° with the top, in normal DB's, but there is no 'correct' value. It is a choice, to be made in balance with many others choices in the design of the instrument. Why do you ask? Instruments are normally designed so that the heel's tenon fits snugly in the neck block's mortise, without gap at the bottom. But yes, now that the thing is out you can change that (and the overstand & bridge height). Please speak with your luthier.

 

[dbassnut]

I'm not entirely certain what I saw, but I think I saw the built-up heel & artistic purfling in a ply back. Because of that & because of the wood seen, I raised the option of a cost-effective replacement combo. Is this an Indonesian instrument?

Btw, a built-up heel is more a monetary rather than a technical issue.

Now that the heel is out, I'd probably place a reinforcement across the old break, scrape the FB as required & re-glue the heel. That seems cheapest, but I might be wrong. Once again: your luthiers cost estimates should guide you. Fitting a new heel takes time too.

The strings often make an angle between 11.5° & 13.5° with the top, in normal DB's, but there is no 'correct' value. It is a choice, to be made in balance with many others choices in the design of the instrument. Why do you ask? Instruments are normally designed so that the heel's tenon fits snugly in the neck block's mortise, without gap at the bottom. But yes, now that the thing is out you can change that (and the overstand & bridge height). Please speak with your luthier.

Hi Ortsom,
Thanks for the information.
The instrument is a chinese hand carved solid wood bass which used to belong to my late teacher.
About the angle, well, the first time the neck snapped off, we glued the neck back on but did not check for the correct angle so the needed to use a much higher bridge. Only noticed this after comparing this to other visiting bassist instruments. Would like to get this done right as am now re installing the neck instead of replacing it as my luthier doesn't have a blank neck at the moment and I can't wait for him to go get one at the end of the year.
Should be getting my baby back next week & will post a photo here.

 

[Ortsom]

OK, thanks for the info. Apologies, I inferred wrong from the pics then.

Some basses have taller bridges than others. But if you needed a much taller bridge after the first repair than before that repair, you have changed the geometry & may want to correct for that now. Best use the original bridge height from this bass, not the bridge height from someone else's bass; or of course the judgement of your luthier. (Top curvature is as important as bridge height: a low bridge on a strongly curved top might give more string angle than a tall bridge on a relatively flat top.)