Using candle wax to keep a vintage P-90 working

Issue 15 February 01, 2007

The Curse of the Mummy!

Curse of the mummy

It was a dark and stormy night, and the clock struck midnight as I lifted the cover off this venerable old P-90 pickup. Opening up this ’57 Les Paul Jr. was like entering King Tut’s tomb. I even wound up going in there with a candle, as you’ll see...

As I gently removed the cover, I said “Uh-oh!”

Like a copper-wrapped mummy, this pickup was disintegrating with age...

Old pickup

This P-90 still sounded like a million bucks, but it wanted to crumble into a million bits.

There were even pieces missing. Now the question was, should I leave it alone and sneak the cover back on, or should I try to fix it? I checked it with a multimeter, and it worked — reading 8.35k. (I should have done that check before removing the cover!)

I felt like I should put something over King Tut’s exposed windings before his cover went back on. Black superglue? Epoxy? I called my friend Lindy Fralin, the master pickup maker, and e-mailed him a picture.

Lindy Fralin’s advice:

Dan, I’ll bet you can leave it alone and it’ll sound great for years and years. Especially since the plastic’s just broken, not rotted. Sometimes we see P-90s that no longer work, with decaying plastic and corroded coils. Those bobbins need to be rebuilt or replaced.

Lindy Franlin

Because this pickup works, and because the coil has kept its original shape, and not expanded, it’s a candidate for this repair. By expanded I mean when the plastic bobbin has cracked and fallen away — no longer supporting the coil, and the coil expands upward into the areas where the plastic had been.

Light a candle, and dribble hot wax over the exposed copper wire. Mask off around the pickup by cutting a pickup-shaped hole in a piece of paper. Don’t tape it down; tape and dry old finishes don’t mix. You can slide the paper around with one hand so that it’s always protecting the area where you are waxing. Don’t use potting wax or beeswax because it’s too hot. You don’t want to get the parts hot. Candle wax melts at a much lower temperature.

Candle wax on pickup
Candle wax on pickup dried

Don’t worry if the wax cools fast and is lumpy. You can smooth it with a low-wattage soldering iron — just like frosting a cake. Touch only the wax, and not any part of the pickup; the wax will respond instantly, you’ll see.

Back to Dan:

I was nervous about the soldering iron, and afraid I wouldn’t have Lindy’s skill at this, so I used my offset knife heated over an alcohol lamp instead. I bent my knife a little to give it a slight “spoon” curve.

Offset knife and alcohol lamp

Lindy was right: the wax smoothed out, and the cover to fit back on perfectly.

Spreading wax on pickup
Putting the pickup cover back

I escaped the Mummy's Curse. Thanks, Lindy!

Neat tip in case your fingers slip!

Put a piece of plastic tubing over your screwdriver when you start a pickup screw into its hole. The tubing holds the screw, and if you slip, the rubber protects the finish. -Dan

Related items