Double Bass Neck help for a '59 Kay DB.

[RobG]

When I got this bass the neck was straight from nut to tail. No curve (relief) as I like it. It came with weed whackers which went by by along with the bridge. A new adjustable bridge and several iterations of strings over 8 years and all seemed fine. A couple of years ago I settled on Pirastro Obligatos because of their sound and lower tenstion. Since then the neck as been bending much like adjusting in relief in an electric with a truss rod. More where it is thinner near the nut and less towards the body. There are no physical issues like fingerboard delamination or a loose set. How can I stop this, reverse it and prevent it from happening again?
Thanks in advance.

 

[Jake deVilliers]

My favourite way to fix that is to remove the fingerboard, clamp the neck straight and install a carbon fibre stiffener.

Re-install the board, dress and you're good for a long, long time.

It really makes a big difference on those Kays where the neck was a little on the small side.

I have some pix here.
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[Bob Branstetter]

If changing the strings created enough tension to bend the neck, you've probably got a fingerboard that is too thin. You could do as Jake suggests and install a CF bar, but a new Ebony fingerboard would be a better long term solution. That would stiffen the neck as well giving you more wood for down the road as the fingerboad wears and needs re-planning a few times.

 

[Standalone]

I have a thin-fingerboarded Kay with high action myself. That makes a lot of sense-- I wonder if the high action on mine is resulting from a similar situation. Could I expect the neck to straighten out on its own if I re-did only the fingerboard?

 

[Jake deVilliers]

As Bob pointed out, if the board's thin you should replace it.

And while its off, reinforce the neck with 1/4" x 1/2" x 18" CF.

I'm always amazed at how floppy Kay necks are once you've removed the fingerboard. I don't think its good structurally or sonically, so I prefer to address that shortcoming.

You can check your neck for bend by sighting down the line between the neck & the fingerboard. Many are curved there.

 

[Bob Branstetter]

As Bob pointed out, if the board's thin you should replace it.

And while its off, reinforce the neck with 1/4" x 1/2" x 18" CF.

A Carbon Fibre reinforcement is not necessary or needed if a good Ebony fingerboard is properly installed.