Double Bass Hatchet Job on a Neck Pocket

[pi_r_squared]

I had only done one previous reset on a neck on a Chinese bass so cheap that I had nothing to loose.

This bass is a little bit nicer, so I don't want to completely fly by the seat of my pants.

I had a neck joint that had partially let go, so I pulled the neck (combination of prying the joint and introducing isopropyl alcohol). got the sides loose, and after enough time the bottom of the joint let loose as well.

Neck is off, needs glue cleaned off, the gluing surfaces look great.

The neck pocket in the body is a different story.

Sides are nice, the button is as well, but the bottom of the pocket looks like someone took a hatchet to it. OK, it was more likely a chisel, but still.....

There is a small flat area at the front, and a small flat area at the back that appear flush, and look like they were part of the glued joint, but about 75% of the bottom surface of the pocket has been chiseled to below the level of these 2 surfaces (over 1/8" below in some areas). Glue had been applied to this area, but was obviously not holding anything. I'll try to attach photos tomorrow.

I could build a router fixture that would clamp to the top of the body, and take the whole pocket 1/4" deeper, glue a 1/4" shim, then glue the neck, but that seems drastic.

Is there some sort of filler that is strong enough to fill this in? I would only be filling UP TO the 2 small surfaces that already appear to be in the proper place. Is there wood filler that has this sort of structural capability? or would I be better off with a polyester resin filler? or???

Thanks in advance.

 

[Jake deVilliers]

You just need to make the bottom of the mortise a regular shape, chalk fit a filler piece in matching wood and glue it in. Then you can fit the neck properly, adjust the neck angle and glue in the neck.

What's so hard about that?

 

[pi_r_squared]

Here's a photo of the neck pocket described above (if I attached it correctly).

I've talked to one luthier who would not take issue with using epoxy filler on a (non vintage) plywood bass like this one, and another who sort of shrugged and said it probably wouldn't hurt, but he would still carve it out and glue in a filler block.

Opinions appreciated.

Thanks again.

 

[eh_train]

If the worst part of the "chewed up" area is only 3/16" deep, it should be relatively easy to "lower" the entire floor of the mortise by 1/4" using a chisel or gouge. Then you'll have a fresh flat surface to reglue. If losing 1/4" of neck height is seen as a problem, you can glue in a shim to restore the height once you have a flat surface.

At least, that's what I'd do...

Cheers,
Paul (eh_train)

 

[KUNGfuSHERIFF]

Or you could sink a captive nut into the mortise and have a removable-neck travel bass.

Are my eyes playing tricks, or is the button 3/4" thick?

 

[tyb507]

Looks like the heel was "stacked".

 

[Turnaround]

Often there is a gap between the end of the neck and the block. It's probably not a big deal because the mating surface will be the end grain of the neck. End grain does not bond well since the wood fibres are running in the wrong direction for good adhesion. The main part of the joint strength is from the sides if the joint, and that is where a close fit is essential. Having said that, a little extra strength from the end-grain gluing surface may be a bit of help, though it's probably minimal.

I would concentrate on getting a close fit on the sides of the joint and just clean up the bearing surfaces at the end of the neck and block. You want some solid contact there, especially at both ends, but a gap in the middle is of little consequence IMHO.