Hohner "The Jack" Restoration

[Mediocre Polymath]

So this is going to be my first post in the build diaries forum that's actually describing an ongoing project. 

 

A few weeks ago, I gave in to impulse and decided to buy @Chienmortbb's headless Hohner "The Jack". I'd been circling this project bass for a while because I was on the hunt for some decent (but not astronomically expensive) headless bass hardware. I didn't like the idea of cannibalizing a bass that looked more-or-less salvagable, but I figured I'd keep an eye on it just in case he decided to split it up for parts. 

 

The longer I stared at it, and at the complex thru-neck multi-laminate-body design that I'd been working on, the more I realized that a cheap, lightweight and compact bass was something I needed/wanted far more than the custom bass I'd designed. That was a bass that would probably take me several months and end up costing the best part of grand to make. So I contacted Chienmort and said I'd take the Hohner off his hands. 

 

It arrived the week before last, packed with great care and attention, and I was able to take stock of what needed to be done. 

 

 

For anyone who hasn't had a quick look at the original listing, the story of this bass is that it was retrofitted with a Roland midi pickup system by a previous owner. This meant it had three extra holes drilled into the control cavity for switches, a recess cut into the front to fit the pickup under the strings (which the previous owner appears to have done with his teeth) and a massive square-ish hole Boo-Radleyed into the side to accomodate the 13-pin output connector. 

 

 

Whatever I did, I knew that I was going to need to refinish the bass. So the first order of business was to strip off the finish – or as much of the finish as needed stripping away. I tried to use chemical stripper again, and met with exactly the same results as last time I tried to use it on a guitar, which is a whole lot of bugger all. Each application only penetrated into the top few microns of paint, and I probably would have made just as much progress with just a metal scraper on its own. I gave up and switched to an orbital sander, which went much better. My aim was not to go down to the bare wood (solid-colour instruments are always solid colour for a reason) but just to sand until the scratched top layer was gone. 

 

 

With that done, I was ready to start patching up the damage. 

[Hellzero]

Following. 😊

[PaulThePlug]

Had a play with a B2 a while back

Well worth replacing the 3 plastic washers on the tuner screws with a F4-10M Thrust Bearing (4 for about £5) for smoother tuning.

[Mediocre Polymath]

2 minutes ago, PaulThePlug said:

Had a play with a B2 a while back

Well worth replacing the 3 plastic washers on the tuner screws with a F4-10M Thrust Bearing (4 for about £5) for smoother tuning.

Yeah that mod is definitely on my list of priorities. I also need to do it with my other headless bass, as that can be really hard to turn sometimes. 

[Mediocre Polymath]

I should mention that @Chienmortbb very kindly threw in the Roland midi pickup and its associated internal gubbins gratis, but after an afternoon of reading spec-sheets and sketching ideas, I decided that this wasn't something I wanted for this bass. It would have complicated the project – particularly the wiring – massively, and given that I don't have the accompanying floor unit (and no plans to acquire one) it didn't seem worth the hassle. I'll put it up in the recycling forum when I get a moment to properly inventory what bits are there, because I'm sure it's of use to someone.

 

Having ruled that out, I started going through the steps I'd need to take to restore it to stock condition. 

 

I decided, after a fair while spend staring and mumbling to myself, that the hole in the side called for drastic measures. If I was to make this bass look decent and return it to its original configuration (with the strap button on either side of the bridge) I needed to plug the hole, but the current routing (if you can call it that) was so raggedy that squaring it off well enough to glue in a plug would be near impossible. 

 

Therefore, I grabbed my chisels and a sharp tenon saw and cut out the whole section. No way out but through!

 

 

After tidying this new gouge, I cut a piece of wood from some scrap timber I had in my heap of scrap timber (everyone should have a good heap). This was planed and finessed into shape. 

 

 

I used rasps and sharp little chisels to cut the recess for the control cover. Then slathered the whole thing in titebond and left it overnight. Once the glue had set up, I carved away the excess with rasps and files. I'll fill in the remaining little gaps with epoxy once I've sorted out the other things.   

 

 

 

 

[PaulThePlug]

Good Darts!..

I'd gone Penny Washer, M5 Bolt, Nylock Nut!

Watching with interest.

[Mediocre Polymath]

So, having sorted out the damage to the back, it was time to figure out what to do about the damage on the front. This wasn't as bad as the great big hole, but it was ugly, and in a very visible spot on the front of the instrument. Here's a picture of it after I'd finished the sanding, the black lacquer dust that got into the grain makes the detail of the damage easier to see in a photo. 

 

 

I decided that, as with the hole in the side, I was going to have to make a bigger but neater hole if I was going to patch this cleanly. First I drilled two 20-mm diameter holes centered on the existing screw holes for the Roland GK pickup. I used a forstner bit, so the holes are completely flat at the bottom. The drill stand meant that I was able to make each hole exatly 3 mm deep. 

 

 

Once that was done, I used the router base for my dremel to join the two holes up and create a uniform 3-mm deep channel where the gouge was. In theory I probably could have done all this with the dremel, but the plunge functions of that router base are really wobbly and unreliable, so I prefer to pre-drill and then have it set at a fixed depth. 

 

 

Here's the finished channel, and the maple inlay piece I shaped to fit inside it. This was scrap rock maple from an old guitar build, painstakingly shaped and measured out, not – as it unfortunately looks – the stick from an ice-lolly that I fished out of a bin. 

 

 

This was glued in with the help of an enormous brick of PTFE (non stick!), trimmed to shape and planed level. The plane I used for this has a blade that I ground into a slightly convex shape, so I can use it on surfaces like this without worrying about a sharp corner digging in. 

 

 

And here's the finished patch. (I fixed that little notch in the right hand side of the bridge cutout). 

 

[BassTool]

Great work so far 👍🏼

[Mediocre Polymath]

Thanks. In other news, I'm currently trying to order some of the electric gubbins I'll need to finish this job, and generally raging at the electronics gods.

 

Why is it that if you need, say, a 500k blend pot and two 500k audio taper pots, every shop will only have one or the other in stock, or they'll have both in stock but with different bushing lengths, or shaft types, or bushing diameters!

 

Then when you finally find a shop that has an acceptably close-enough set of components, they don't have any barrel jacks, or knobs!

 

Every time I place an order for guitar parts I end up having to buy like six small and inexpensive items from three or four different shops, paying as much for shipping as I do for parts. This is despite each shop, in theory, selling everything I need.

 

As it is, I think I'm going to have to get the knobs, strap buttons and one of the two types of pot from Northwest, the output jack, other kind of pot and pickup rings from Armstrong and the fretwire from Tonetech.

 

 

Edited 7 hours ago by Mediocre Polymath

[PaulThePlug]

Vol, 3 Way Pup Select, Jack...

[itu]

1 hour ago, Mediocre Polymath said:

Every time I place an order for guitar parts I end up having to buy like six small and inexpensive items from three or four different shops, paying as much for shipping as I do for parts. 

How about contacting @KiOgon? 

 

(I do feel your pain. Last time I ordered components, opamps were of wrong footprint.) 

[Mediocre Polymath]

12 minutes ago, itu said:

How about contacting @KiOgon? 

 

(I do feel your pain. Last time I ordered components, opamps were of wrong footprint.) 

 

It's a matter of tradition for me that every time I put in a big order with Digikey or CPC, at least one of the components I've bought will turn out to be wildly off spec – we're talking resistors rated to 600 volts the size of my thumb, or surface mount capacitors the size of a grain of sand.