Pickup potting question.

[SamBooka]

99% of the time I play jazz.. at home.. while the kids are sleeping.
BUT every decade I will play in a club a few old fart songs. This year it was my tele with my YGM-4 and a boss SD-1.

Not exactly high-gain mahem. In fact I was barely keeping up with the drummer who was pretty tame to begin with.

The neck pickup (an embossed 70s Gibson HB) squealed like a stuck pig so I am thinking of waxing it (I figure I have about 9 years to get it done).

Did SOME homework. 80/20 mix of Parafin/Beeswax. Temp at 150deg (use a confectioners thermometer). Soak until the bubbles stop (15 min max).

My question is this: I am not taking the pickup cover off to wax it. Do I make an effort to drain as much was out of the cover when I pull it out or let the wax stay inside?

I did this once before when i was a kid on my epi pickups (so that would have been aroun 93 or so). Only used parafin. Temp be damned. Soaked for maybe 2 minutes. Tried to keep as much wax inside the covers as possible. It wasnt a huge success

Any advice is appreciated.

Drew

[walterw]

first, make sure that cover is securely soldered on. i'll sometimes even re-do one if the cover has a gap at the top, clamping it down onto the pickup to ensure that it presses against the face of the pickup when i solder it back on.

once that's done, submerging cover-side down for only a minute or two (til the bubbles stop streaming) then letting the wax drain back out is usually plenty to stop the squealies.

do an initial wipe-off with paper towels while the wax is still melted, then naphtha is useful to clean the rest of the wax off the outside once everything cools down.

[gunslinger]

Could the squealing be caused by something other than the pickup?

[walterw]

the fact that he says the neck squeals (as opposed to the bridge) makes me think no.

[SamBooka]

The pickup HAS seen better days but I got it for free and it does sound great. There isnt much soldering holding the cover in place but it seems solid enough. Could it be something else? Sure. But it only happens on the neck pickup. It is a tele and the bridge pickups can be kinda noisy too.

[chervokas]

I've had good success wax potting some squealing pickups using one of those parafin hand soaking spa things that you can get at Bed Bath and Beyond. You have to watch the temperature but it's pretty good for keeping the wax at the right temperature (though enought beeswax to fill one of those things to 20% isn't all that cheap). But the devices are inexpensive and they are designed to keep the wax at a constant low temp above it's melting point. It's not the perfect potting system--without a vacuum you really don't fully coat the windings--but it's sufficient to solve a problem with a really microphonic pickup.

One word of caution: butyrate bobbins have a lower melting point than some of the other plastic used for bobbins and I've heard stories (maybe apocryphal since I never heard 'em first hand) of people melting bobbins on humbuckers. Probably the 70s Gibson HBs didn't have butyrate bobbins, but worth making sure.

[HipKitty]

Originally Posted by gunslinger

Could the squealing be caused by something other than the pickup?

Yes, the springs can cause microphonics at high gain levels. I recommend surgical tubing instead.

[SamBooka]

Originally Posted by chervokas

One word of caution: butyrate bobbins have a lower melting point than some of the other plastic used for bobbins and I've heard stories (maybe apocryphal since I never heard 'em first hand) of people melting bobbins on humbuckers. Probably the 70s Gibson HBs didn't have butyrate bobbins, but worth making sure.

That is my biggest concern but from what I have read keeping the temp below 150 should be safe. I remember EdVH saying he toasted a PAF that way in the 70s.

[gunslinger]

Originally Posted by SamBooka

My question is this: I am not taking the pickup cover off to wax it. Do I make an effort to drain as much was out of the cover when I pull it out or let the wax stay inside?

Isn't taking the cover off the best way to get the coils saturated with wax?

[chervokas]

Originally Posted by gunslinger

Isn't taking the cover off the best way to get the coils saturated with wax?

Well, often the squealing from a humbucker can result from the cover vibrating and can be solved by some kind of silicone adhesive between the cover and the pickup or potting w/ the cover on as I understand it. No first hand experience, that's just what I've been told.

[Rob DiStefano]

yes, yer pup needs potting, and a wax blend is best. i use 70% paraffin and 30% pure beeswax. no need to take off the cover (or tape) as the wax will get into every nook and cranny whether you want it to or not - just wipe down the pup after it's pulled from the pot. i use a double boiler on an electric hot plate and a candy thermometer to check the wax temperature. i get the wax to 155-160F and dunk the pup(s), the temp will slowly drop to 150-145F as it's cooled by the addition of the pup(s). i allow at *least* 30 minutes in the pot, agitating each pup every 5-8 minutes or so to make sure the air escapes. it's not uncommon for me to wax pot for nearly an hour - the longer, the better, just to be absolutely sure.

[plagtr2]

Depends on the pickup & the type of squeal you are getting, but I have a few unpotted humbuckers that I play with a fair amout of gain. A p90 guitar too. I have had to "re-do" a cover or two to tame noise. I added the covers & did not get them perfect. They squealed. I learned from somewhere to use a bit of silicone between the cover and the top of the pickup. That and a couple of small spring loaded clamps to hold the cover in place while soldering. Doing this and making sure that everything is "right" has helped alot with unpotted & covered pickups. I'd almost want to try that first before potting--which make take away from the tone of the pickup.
Another angle is sending the pup to one of the fine pickup winders/repair folks and let them assess & do the repair for you. Lindy Frailin fixed up leads on a PAF my buddy had--did a great job & was not "invasive" on the repair at all.