Trade Secrets!

Using candle wax to keep a vintage P-90 working


Issue 15 February 01, 2007

Photo: Curse of the mummy
The 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...

Dan Erlewine signature Dan Erlewine, February 1, 2007
Photo: Dan Erlewine
As I gently removed the cover, I said “Uh-oh!”
Photo: old pickup
Like a copper-wrapped mummy, this pickup was disintegrating with age...

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:
Photo: Lindy Fralin
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.

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.





Image: screwdriver tip

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
Photo: candle wax on pickup

Photo: candle wax on pickup
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.

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:
Photo: offset knife and alcohol lamp
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. 

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

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

Dan Erlewine signature

Problem-solving products mentioned above:
Photo: Portable Digital Multimeter Photo: Offset Disassembly Knife Photo: Alcohol Lamp
Portable Digital Multimeter
Test continuity, AC/DC voltages, amperage, and ohm resistance of pots and pickups.
Offset Disassembly Knife
This knife's handle is offset to protect the soundboard when lifting a bridge or fingerboard, cleaning glue from a loose brace, or for similar tasks.
Alcohol Lamp
Ideal for heating a burn-in knife when applying engraving filler or lacquer touch-up sticks.
Buy Now
Buy Now
Buy Now
Photo: Humbucker Pickup Parts Photo: Single-coil Pickup Parts Photo: Golden Age Pickups
Humbucker Pickup Parts
Vintage-style humbucker pickup parts. Bobbins, magnets, and everything you need to repair or build your own.
Single-coil Pickup Parts
Vintage-specification single-coil Stratocaster and Telecaster pickups parts.
Golden Age Pickups
Golden Age pickups have the tone and response of the classic 50's pickups. Single-coils and humbuckers.
Buy Now
Buy Now
Buy Now

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