potting humbuckers....

[Possum]

I've never really potted humbuckers before so need some advice. My new Star set sound great but they squeal, it may be because the bobbins aren't PAF correct and some slight mismatch in parts is causing squeal, but I dunked the bottom part of the bucker in wax to see if it would solidify the keeper and related parts, but it still squeals. The coils aren't wound loose either. BTW there is no cover on this test pickup.

So I'm going to try potting the whole pickup but this is an UNcovered pickup. So the coils are already wrapped, will soaking it in wax really penetrate the coil through the tiny 2 holes in the bobbin are do you guys pot the coil before putting the leads on? I"m using paper tape and for sure wax isn't going to penetrate the stuff I"m using.

[SkinnyWire]

Some folks actually prefer a bit of microphonic character in their pickups. The pickups that I build for my own use I leave unpotted. Get in the wrong spot in the room and they'll squeal a bit, but the slightly better sensitivity that seems to come with the pickup being "on edge" adds another dimension to the pickup. I test through a '73 Super Lead full stack, so there's plenty of opportunity for feedback.

That said, I pot the pickups I ship unless requested otherwise. IMO (FWIW), good potting should have little to no impact on the tone/character of the pickup and you don't really need deep saturation/penetration such as in vacuum potting to mitigate the squeal enough for most applications. Enough wax will make it through the sight holes and under the tape to do the job. I only use paper tape as a final cosmetic wrap so I don't have any issues with the tape coming lose in the pot. You might want to wrap a couple of rubber bands around the pair of coils to keep the paper tape in place and wait 'til after potting for the final finishing wrap.

I have a big box fan next to my pot, and wipe the tops of the bobbins clean with tissue while setting the wax just enough to stop it from running. Sometimes I wipe the whole thing frame and all, but it's a bitch around the screws on the underside.

[kevinT]

I pretty much do what skinny does. My mix is a 3 to 1 pariffan to bee's wax. And i am eventually going to try a 2 to 1 ratio. I really don't hear much of an effect on the tone from the potting. I have a timer and leave them in for about 8 to 9 minutes. I also recommend rubber bands to keep the paper tape from unraveling. My shop is in my basement and it is cool which helps the wax to solidify which is a good thing....the faster the better. I make sure that i wipe away all the wax on the bottom of the baseplate where the solder joints for the covers will go in order to prevent any problems.

[kevinT]

couple of other things ...I don't let the pickup sit on the bottom or touch the sides of the heat source so as to not melt the bobbins. The heating element/source is usually hotter than the wax. I have a basket that hangs which leaves room between the bottom of the fryer and the basket.

I also move the pickup around every few minutes and position it differently (on its side, top facing up, and down, etc...) in the basket in order for gravity to force the wax into different areas of the pickup as the pickup is submerged.

[SkinnyWire]

couple of other things ...I don't let the pickup sit on the bottom or touch the sides of the heat source so as to not melt the bobbins. The heating element/source is usually hotter than the wax. I have a basket that hangs which leaves room between the bottom of the fryer and the basket.

I also move the pickup around every few minutes and position it differently (on its side, top facing up, and down, etc...) in the basket in order for gravity to force the wax into different areas of the pickup as the pickup is submerged.

Sounds like we think alike on a lot of things.

I hang them from a piece of wood so they're suspended in the wax using a piece of wire. Even though I use a double-boiler method (wax in a pot floating in water), so the pot really shouldn't be hotter than the wax, I figure the bobbins could get scratched on the bottom. Jiggle them about until the frame is heated (no solid wax on it) and then let them "steep".

[John_H]

I wrap with paper tape, and put a rubber band around the assembly so the tape won't unravel. I use a double boiler. It just seems safer to me. I don't usually have the wax over 150f. I also heat the pickups to the same temperature as the mix, and soak them for about five minutes agitating two or three times. I've always let them cool slowly. An abrupt change in temperature doesn't seem beneficial to me. During the summer when it's regularly 110f here in the middle of the Mojave desert I set my wax pot, and the pickups in the sun to preheat.

[Possum]

...

whats the best way to clean the things off, I have some Holmes pickups and they are spotless on the top of the bobbins and the bottom of the baseplate....

[kevinT]

whats the best way to clean the things off, I have some Holmes pickups and they are spotless on the top of the bobbins and the bottom of the baseplate....

I don't think you'll ever get them spotless unless you really spend a lot of time on them...and would it be worth it?...To me, a little wax adds to the character in that they are handcrafted. All the pickups that i've seen have some indication that they have been wax potted. From Seymours to the cheap stock Korean pickups that come in some of my lower end guitars.

I initially use a paper towel to wipe them off when they come out of the pot. However, I think Microfiber works best in the final cleanup/detailing when they cool down. The wicking action of Microfiber actually lifts the wax from the surface instead of smearing it. And it will not scratch at all. ...you can get them at any auto parts store.

Spence mentioned baby wipes which i am going to try. I have plenty of them as i have a 1-year-old.

[SkinnyWire]

I clean them initially with facial tissue. Some tissue can be a bit "dustier" than other brands, but they don't seem to scratch the plastic at all. For a final polish I use lint-free shop clothes - the sort of blue/white speckled looking things you can buy in a pack or box.

Also, 91% Isopropyl on a tissue or cloth will remove all residue though it's still a bitch around the screws and where the hookup enters the bottom of the frame if you want a spotless frame. For that, you can dip a Q-Tip in the Isopropyl and use a combination of that and cloth/tissue. The micro fiber is probably a good bet too. I've never had anyone complain about wax on the bottom of the frame. I do try to dry it more to a more or less uniform appearance.

I just like to have the tops of the bobbins spotless and clean the wax off the tape fairly well so I can put the final paper tape wrap over it. The sides of the frames need to be clean though to allow the tape to stick there.

Regarding rapid cooling, I don't like the idea of dropping the temp too fast either. The fan is more or less to develop a skin over the wax. I'm rubbing the bobbins with tissue at the same time in front of the fan, which makes it easier to remove the wax. Trying to wipe them clean while they're still hot enough for the wax to run is an exercise in futility.

[Possum]

...

If you're potting them with covers on how do you keep the wax from running out where the pole screws are on top? a piece of tape over it to keep the wax in the pickups?

[John_H]

I use a couple little strips of felt as shims between the cover, and the tops of the bobbins. They saturate easily, and bond things together. I pour all the excess wax out that I can.

[Spence]

I've mentioned this before I'm sure. Baby wipes. Very cheap.

[Possum]

...

Spence, I"m getting tired of looking at that same sheep face, she isn't all that cute, do you have a better looking one? She's kinda bhhaaaaaaaaaaaaaa-d

[greenfingers]

Its not the sheep's fault it ain't looking its best. Hot wax for pickups only,

[Spence]

I never look at the face! You don't look at the mantlepiece when you're poking the fire.
Anyway, I'm a bit busy right now with the shearing.