The "other" zombie bass build

Some of you may remember my resurrected lefty 6 string, which I completed recently - 19 years after starting the project. In that thread, I mentioned that I had started a 5 string right handed version of roughly the same bass and had originally intended to keep the lefty and sell the 5 string righty to finance the project. Well, time changes everything...

I finished the lefty per my build thread:

First bass, Zombie build, completed after 19 years

At that time, I basically set the righty aside, not really having any plans for it. Last weekend, my 12 year old son, who is right handed, asked me to teach him something on bass. None of my kids have expressed any interest whatsoever in playing bass, so I jumped at the chance and grabbed my old Ibanez, restrung it right handed, and showed him a few simple lines.

Well, he's been playing it literally non stop, and last night I was in my shop fiddling with something when it hit me - I should finish the right handed bass with him so he can play it! He loved the idea and we agreed to build it together.

I got it down off the shelf and examined it. It's in OK shape, and nearly complete, but back in the day I had torn half the frets out. I vaguely remembered being unhappy with a slight twist in the neck, and tearing the frets out so I could re-level the fretboard, so I got some appropriate tools and showed him how to take the remaining frets out safely, which he did in about 30 seconds.

Sure enough, there's a little bow in the neck, which I figured was fine, because the truss rod can straighten it. But there's maybe 1/32" more bow along the bass side vs the treble side. So I grabbed my truing block and helped him sand it mostly true. Then I got an allen key and attempted to remove the slight remaining bow.

An eighth of a turn was not quite enough. Another eighth, still not enough. I went for a third eighth, and was shocked to hear a loud POP accompanied with the feeling of the truss rod going totally slack.

So, that brings me up to date. I have a 95% completed bass, which now needs a new truss rod. I guess I can permanently fix the bow while I have the fretboard off.



My son has pretty small hands, ideally I would like to have him playing a 30" scale 4 string, not this 34" scale 5 string. Which leaves me wondering if I should attempt to re-profile the neck more narrow, cut the fretboard down, and rebuild this as a 4 string. Maybe even saw off the headstock, take some length out of the neck, graft it back on, install a totally new fretboard with frets spaced for 30" scale?

Or maybe just build this as-is, and pick up a cheap Ibanez mikro or other sub-$100-used bass in the meantime...

The good news is I have a set of bartolini jazz pickups for this already. The bad news is, the 3 band active eq I bought doesn't fit in the control compartment.

Lots of opportunity here. This will probably be a slow build thread now that warm weather is here and there's more to do outside!

 

What can I say, I like to be stylish and comfortable in the shop.

More daydreaming about what to do with this thing. I could hack the neck right off, route a pocket, and convert to bolt-on. I do have a spare neck blank I had made along with the guitar in my other thread that would work as a short scale bass neck...

 

If I keep this neck but cut it narrower to convert to 4 string, I may go headless since the headstock is drilled for 5 tuners, and I need a new bridge anyways. I'm not sure the plan to cut the neck narrower will work though since I remember putting carbon bars in this neck, spaced pretty widely.

I might just try to pull the fretboard off for starters, see how that goes, and then decide. If the fretboard is stubborn in coming off or the neck gets damaged, or the carbon bars are spaced as widely as I remember, then I think the plan to cut the neck off and route for a bolt on or glue in neck makes sense.

I measured from the bridge to establish a rough neck pocket position to validate that a bolt on conversion would be possible with my spare neck blank, at a 30" scale, and it looks like this:



The bolt hole x's were just daydreaming, not a serious attempt to locate holes, but I do think there would be enough meat to locate the neck like this even though two of the holes would be on the existing "slope" of the neck/body transition.

 

Just got home from work and broke out the heat gun and some old putty knives. Time to open this thing up...



Getting to that point took about 20 minutes of slow and steady heating and pushing. Then, success! it popped right off.



Before I could pull the truss rod out I noticed something cool. I had written my initials and the date (3 Jan 99) right under the nut end of the fretboard. Pardon the sloppy channel, I don't think I really quite knew what I was doing back then!



The threads on the truss rod look all rusty in that photo but it was just sanding dust. They're nice and crisp under the dust and everything turns easily. The failure was the weld.



So now I guess it's time to figure out what to do with this thing. I probably have enough width to narrow the neck to a wide-ish 4 string width if I want. The bad news is, now with the fretboard off, I can see that the bow on the neck is actually worse. So I'll have to determine what to do about that if I keep the neck. It's probably a good 3/32" of bow. Pretty discouraging, I'm not super excited about the prospect of planing or routing the surface flat given the carbon rods in there. And I don't want to try to heat-set it (also because of the carbon, and because I don't know if I trust a heat set to remain permanent).

 

My son decided he wanted to try to convert to headless with the existing neck. He wants to do the work himself so I'm coaching him through it. It needs to get narrower but the carbon bars are too close to the edges to allow a good 4 string width. So we decided to get drastic.

First order of business, off with it's head!


(don't worry, this was posed - he wore shoes and used better technique for the actual cut).

Then we broke out the mini bandsaw. If the carbon is too close to cut the outsides of the neck narrower, we figured we could narrow it from the inside out!



And here's the slice we cut from the middle:



By the time we joint the cut surface we will lose about half an inch down the middle. Of course this kills the dimensions of the pickup routes but they were for 5 string jazz pickups anyways. After the body is glued back together we will route for a soapbar shape.

I have to admit it was really fun to literally hack this thing apart!

 

I put each half in the router planing jig and planed them flat. It was a struggle to get them clamped in since they're so irregularly shaped. Especially the neck, since it's already shaped. I ended up using a bunch of shims to keep it tight. We will glue it back together some time this weekend probably, but for now I just lined the joint up and put a clamp on, and I'm very happy. The center maple stripe is almost perfectly quartered so the seam easily disappears since there aren't obvious grain lines.



Once it's glued, I'll clamp it back in the jig and router-plane the face of the neck to remove that excessive bow.

 

I ripped out our master bathroom shortly after that last post so it's been a busy few weeks with nearly zero instrument building time. We did get a chance to glue the bass back together, and last night I put it in a router planing jig and flattened the neck surface. It took a lot of careful shimming and clamping to get the bass positioned correctly in the jig to hold the neck still in the right position relative to the jig, but also ensure that the neck was not being distorted. But, checking with a straightedge after the fact shows it turned out perfectly, so I'm happy.

Also, the headless hardware showed up. I'm happy with that, too. The bridge weighs more than I expected but I guess that's not a big deal since the instrument will be pretty light otherwise.

Next up we have to route out a pocket for the bridge, and route the truss rod channel and new pickup cavities. I'm waiting on a new truss rod, I don't have any on hand that are the right length.



I need to go study photos in some of you other builders' headless bass builds so I can make sure I'm understanding the headpiece correctly before I trim the neck to the final length, too.

 

@Jisch I was hoping you'd show up! This is the bridge you've talked about where the knobs pull out. I did notice the bridge was off center. That works well for me because it's off center in a way that keeps a little more wood between the bridge cutout and where the control cavity is.

I'm gonna dig through your threads. Do you have any close-ups of the head end of the neck? I'm curious to see what a typical arrangement is for the nut and the little string holder. I've never actually seen a headless bass in person so I'm in uncharted territory here!

 

Thanks, those are very helpful! I was wondering about the little step at the front of the head piece. It looks like you have a shim under your nut that extends under that step. That's about what I was thinking, too.

 

Slotted and radiused the fretboard last night. He picked purpleheart so it would match what had originally been on there.