Beach neck and Ebony fingerboard separation

bribass · #1 10-12-2006, 01:44 AM

On my early 1900's German Gamba bass there is a neck made from Beach. Not maple. In the more humid months of the summer in this area the neck seems to bow or warp just a bit despite its fairly thick ebony fingerboard. It's just enough so that the middle positions feel higher and stiff as compared to the lower positions and thumb position w/ the action adjusted properly. This past summer it felt worse and I opted not to use this bass much in favor of my other two basses. I discussed the possibility of installing a graphic rod w/ a luthier in order to stiffen up the neck. Today I played that bass to see how it felt now that the weather is cooling. Well, It feels no better, and I also noticed a sliver of daylight coming thru between the neck wood and the fingerboard! You can also feel the the edge of the neckwood is not flush against the side of the ebony in this area of the lower positions. However the glue joint at the overstand seems secure. Could this partial separation be why the bass feels (and sounds) not quite as good as it was?
Maybe the regluing of the fingerboard would be a good time to install that graphite rod. Any opinions out there from the good luthier/repair people?

THANKS, BG

Jake deVilliers · #2 10-12-2006, 09:41 AM

I am a big fan of carbon fibre neck reinforcement and install a rectangular 1/2" x 1/4" x ~18" stiffener in many basses whose fingerboards I remove. It keeps the neck straight even as the fingerboard becomes progressively thinner as it is re-profiled.

The material is very lightweight while being incredibly stiff.

The procedure seems to slightly improve the higher frequency tone production according to the players I've done it for, especially on intruments with smaller necks.

Jeff Bollbach · #3 10-12-2006, 10:39 AM

While beech is often a bit lighter than most maples if it is thick enough it will be an adequate wood for a neck. But any neck is only as good as the joint between it and the fingerboard. A poor joint will lead to the warping of any neck. The install of the rod is certainly easy if you have to redo the joint so now would be the time for sure. Is it 100% necessary? Hard to say, if the beech is thick enough and the board is as well then with a good joint you should be ok. But there's no real downside to the rod install and plenty of positive to it.

**Matthew Tucker** · #4 10-12-2006, 03:29 PM

I just bought a couple of those graphite rods. They have a very nice resonance to them, like a tuning fork!

Do you cut a 1/4 groove and install the rod "vertically" or cut a 3/8 or 1/2" groove and install the rod flat?

It's a lot stiffer in the vertical direction, but that would cut quite deeply into the neck.

peasandhoney · #5 10-12-2006, 09:18 PM

just to throw something out there and go agains the grain, might it be the fingerboard that is warping. with the quality of ebony getting poorer and poorer (you can make more money making 12 fine violin fingerboards then one double bass fingerboard) and it is always hard to judge the grain of dark wood. granted, due to density, it wouldnt be as reactive to the fluxuations in environment... and there is always the quick fix of moving somewhere drier...

Jake deVilliers · #6 10-13-2006, 09:35 AM

"Do you cut a 1/4 groove and install the rod "vertically" or cut a 3/8 or 1/2" groove and install the rod flat? "

The fingerboard adds plenty of lateral stiffness.
I install it vertically, so as to resist the pull of the strings. Even on a Kay with their undersized necks there is plenty of wood left.

And once the carbon fibre is epoxied (sorry Jeff!) into the neck there is NO flex whatsoever.

Jeff Bollbach · #7 10-13-2006, 11:57 AM

Quote:

Originally Posted by Jake deVilliers

"Do you cut a 1/4 groove and install the rod "vertically" or cut a 3/8 or 1/2" groove and install the rod flat? "

The fingerboard adds plenty of lateral stiffness.
I install it vertically, so as to resist the pull of the strings. Even on a Kay with their undersized necks there is plenty of wood left.

And once the carbon fibre is epoxied (sorry Jeff!) into the neck there is NO flex whatsoever.

No worry, Jake. I use epoxy and crazy glue in my shop, I just don't put Italian basses back together with them.[unlike certain individuals]. I like and use all glues-well, except gorilla glue. I bought some once and after trying it a few times I threw it out. But not before flinging it to the ground and kicking the tube violently while cursing loudly. One good reason why I work alone.

Jake deVilliers · #8 10-13-2006, 01:56 PM

That was somewhat tongue-in-cheek Jeff, but thanks anyway.

I think that Guarneri himself would be happy to be using modern adhesives. Hide glue is a wonderful way to join wood together but epoxy and CA are absolutely terrific when used appropriately.