Electronics cleanup in a beautiful '58 Gibson: "Little Lefty"

Was the pickup really dead?

Frank’s a lefty just like this guitar, so this Gibson was a great find. But when he plugged it in, what he heard was... nothing. Dead pickup. That’s when I paid a visit to Frank’s shop.

I plugged a multimeter into the jack and got a DC resistance reading of 7.86k when the volume was on 10 — but it kept cutting out and showing an open line. I figured the pots were just really dirty, or maybe the jack was bad. I took the little lefty back to my shop to remove the electronics and flush out the pots with contact cleaner.

Fun and useful gizmo.

I don't like fumbling around with test probes and cables, trying to hold everything in contact while getting a reading, but I do like making tools... So I've made myself this gizmo for testing guitars: a plug with brass tubes soldered to the leads. The multimeter probes insert into those brass tubes. Here’s a link to a Facebook photo album about it:

On this guitar, removing the electronics means first removing the tailpiece in order to free the string ground wire. This wire is pressed against the metal of the tailpiece, grounding the strings to the wiring harness inside. It pulls out along with the electronics. (To get it back in later, I snaked a guitar string in through this hole and attached it to the ground wire with heat shrink tubing.)

The electronics were covered with dust, hairballs and bird’s nests. I vacuumed away all of that before cleaning inside the pots — no sense in blowing this junk into them!

Spray cleaning:

Wearing nitrile gloves, I gave the pots a good flush with DeoxIT, rotating the shafts to flush out the dirt. This did the trick; the loss of sound turned out to be simply due to a dirty control pot.

Crumbly old tape:

I used a clean glue brush to remove the oxidation from the pickup’s baseplate. There was a wrap of old brown masking tape insulating the solder joint connecting the coil’s hot lead to the braided shield output lead. That tape was dry as bone: cracked, crumbling and falling off. It disintigrated when the brush touched it. “Good riddance” I thought, and finished cleaning the baseplate thoroughly. I was confident that I could replicate the old tape fairly easily, and that was the fun part of this job.

I tore off the thin outer layer of paper from a brown cardboard box and coated it with ColorTone platina shellac to give it crispiness and shine like the old tape.

In 10 minutes the shellac had dried enough for me to coat the underside with hot hide glue and let that dry for 35 minutes. The glue would give stickiness to my home-made masking tape.

Cut in a 3/4" strip, I had shiny, vintage, brown “masking tape” almost like Gibson used.

Covering my tracks with dust:

After crumpling it, I wrapped the tape around the solder joint and stuck the wrap together with a touch of hot water. Then I added another coat of shellac to give it a little more shine. The little piece looked a convincing 53 years old.

While the shellac was still sticky, I brushed some dust onto it for a “relic” look. It’ll pass for the original tape now. I was very pleased with the look of it even though nobody else would ever see it. Sometimes I just can’t help myself: it's fun to throw in little extras like this!

Home to papa.

I took the guitar back to Blue Eagle for Frank to check it out: Frank’s happy, I'm happy, and I think Little Lefty looks happy, too!