Tar-like substance under pickguard

Years of nicotine?

 

I don't know. The onmly thing I can think of is sloppily applied shielding paint. Is it dry or sticky? Is the rest of the cavity shielded with black graphite paint? Is it possible to post a pic?

 

Years of string funk??

I'm just guessing, obviously, but with it being such an old bass, look past the obvious. It could be someone once hid a roach in to the pickup cavity and forgot about it, and years of sweat caused a streak.

Again, just guessing.

 

Could it be sap from the wood coming thru the shielding making it black?

 

Either way, try naphtha to clean it.

 

Take off the PG and look first.

 

Probably the pickup height foam breaking down underneath the pickup

 

Definitely do this. It may not be serious and may cause unwanted results if you clean it the wrong way.

 

This!! I never even thought of this, but you're probably right.

 

Yeah this happened to an old jazz of mine. I was having trouble adjusting the pups and when I looked underneath, the foam had been reduced to a sludge like you described.

 

That's what I was going to say.

 

Rip Topaz is correct: Naphtha, or lighter fluid, is OK on shiny poly finishes and your plastic pickguards; it evaporates quickly. It may discolor bare wood. Barring that, IMO, the next best thing is Denatured Alcohol, an old toothbrush and a clean cloth. D-alcohol has NO water and shouldn't stain wood (as far as I know).

Davey4557 on YouTube has a couple of vids about "cleaning yer guitaaaar".

 

Don't use alcohol on nitro. It'll dissolve it. I tried to clean some stand marks on my nitro painted bass and it made the area it touched really cloudy and nasty looking.

 

Yup...if it's black and sticky

 

I actually thought maybe it could be something spilled, and got under there.......
so -
what was the culprit?

 

Without pics it's hard to tell but it's most likely not nicotine. You would smell it if it was dripping off your bass. I'm sticking with foam degradation, as it has happened to me.

 

I suppose the foam is the most likely. The problem reminds me of something a VP at my employer told me many years ago. When he was a kid in the depression he made money fixing Atwater-Kent radios. Evidently he was the only one in his neighborhood who was willing to melt the tar out of the power supply filter can to fix the coils and caps inside. Perhaps in 1974 Fender was potting their pickups with tar??

Ken