Reviving an East German Mandolin

[Mediocre Polymath]

Not a bass, so I figured I'd put this here rather than in the repairs/build-diaries forum. 

 

The weekend after New Year's I headed out to the countryside to collect this old East-German mandolin from @bass_dinger. 

 

I've been a mandolin dilettante for years (family of folk musicians) but I've never had my own one, not really. (I have an electric mandolin I made out of offcuts while working on something else, but I don't play it much). I figured the price was low enough to be worth a punt, and it seemed like whatever work it might need would be well within my skill set as a luthier and tinkerer. (Please excuse the cat, who wanted to be in my picture of the action). As fairly described by Robert, the neck was pretty bowed and the fretwork worn down. It was never a fancy instrument and it had lived a long life. I put in an order with my luthier supply shop of choice and set it aside.

 

 

The following weekend, the first job was to take the frets out. I sat down with my special ground-down end-nippers and started the painstaking process of levering them up. No pictures were taken of this process because it only took about a minute. It turned out the tangs on the frets were not only 1.5 mm deep at most, but also completely smooth – no nibs, no little spikes. I could have probably lifted them out with my fingernails. 

 

 

I clamped the body into place and prepared my special heating tool. This may look like a crappy old clothes iron, but I promise it's a high-tech piece of equipment. I used a pallette knife to get under the fingerboard after it was good and hot and pinged the whole thing off, perfectly intact. 

 

 

 

 

I then routed a channel and stuck a length of carbon-fibre rod in there. Not the neatest job because my router plane was being difficult and it took me a while to remember the quirks of the adjusters on that particular tool. 

 

 

 

Fingerboard clamped back on with the rod in place. The rod is the same size as the one I routed into the (thinner and longer) neck on my electric mandolin, so I'm confident it will hold things straight for the foreseeable future.

 

 

If I'd been more inclined to take my time with this, I would have spent a few hours planing a backward angle into the fingerboard (it's pretty thick and the neck is dead flat to the front of the body, which isn't great). I decided I couldn't be bothered – if nothing else, I explicitly don't want this instrument to be loud. I had to recut the fret slots because even the finest fretwire I had to hand was much chunkier than the stuff that had come out. I didn't take any pictures of the fretting process – just imagine someone smacking an instrument with a nylon-headed hammer for half an hour, swearing the whole time.

 

 

Here's the finished job. I recut the nut and bridge slots, and reshaped the bridge a little, but left it otherwise unchanged. 

 

 

 

As you can see, the action has come down a lot, and the fretwork is now level and even. It plays beautifully and I've already lost several hours to noodling around trying to remember various fiddle tunes. At some point I'll replace the dot markers that melted during the heating process. It sounds like, well, like a £40 mandolin – which is what I expected and what I was hoping for. A fun thing for plinking away at on the sofa and during teams meetings (pro-tip! A mandolin can be played without showing up on the laptop camera if you hold it down low).

Edited 5 hours ago by Mediocre Polymath

[bass_dinger]

It's like sending one's children to Finishing School in Switzerland. 

 

One is surprised to see that they had such potential, but delighted to see that they have been smartened up and made presentable.  Well done @Mediocre Polymath.

 

 

[Rosie C]

Awesome skills! Can I ask, did you glue the carbon fibre rod into the routed channel?

 

[Mediocre Polymath]

56 minutes ago, Rosie C said:

Awesome skills! Can I ask, did you glue the carbon fibre rod into the routed channel?

 

Thanks. There is a lot of glue in the channel, but I don't know if it's actually gluing anything to anything – I can't imagine titebond does much for carbon fibre. The rod is primarily held in place by being smushed between the neck and the fingerboard.