Wax Potting

[texan]

After potting a set of single coils I noticed that the coils actualy swelled up as the wax penetrated. Even after a few day of dry time the coils are still larger than they were before. Is this swelling something I should have accounted for. I used an 80/20 mix of parafin and beeswax. I was trying to soak them until the air bubbles stopped, but ended up removing them at 27 minutes. Thanks

[Spence]

This is just an indication that your coil windings were not as tight as they could have been. Firstly you can push the coil back into the bobbin while the wax is still warm. Secondly you should not need to have the coil in the wax for more than about 10 minutes. Thridly you can use neat paraffin wax if you want. The beeswax just helps to lower the melting point of the paraffin wax.

[SkinnyWire]

Indeed, might be loose winds causing part of the problem. I've also seen this if you don't drain the coil enough after pulling them out. I pull them, let the wax run until it's just dripping, and then wipe the excess off as it's drying in front of a fan (with taped coils). The beeswax also makes things a bit less brittle, which is nice though not necessary I suppose.

[Zhangliqun]

Beeswax also helps if you later need to remove a few turns because it came in over spec, or you just want to lower the number of turns on an existing potted coil. With straight parafin, the wire will break and quick.

[Possum]

........

I usually use too much wax and I supply a string wick cleverly tucked inside the coil in case the electricity goes out at a gig, you can light your guitar and find your way to the bar...

[Zhangliqun]

And Spence is right -- 27 minutes is WAAAAY too long to leave a pickup in the pot. I learned that the hard way...

[Possum]

ooops....

Yeah no kidding, I recently had a "senior moment" and left a tele bridge sitting in 180 degree pot for an hour, oops. The coil started pushing the flatwork off the top of the pickup, ouch. I saved it though, put some clamps on the top and pushed it all back down, when it cooled it was all nicely flat and the coil survived fine. the heat over that time loosed the lacquer which holds the flatwork together.

[NightWinder]

Paraffin by itsself has a shrink when cooled to it as well. Beeswax also stablizes this. Sometimes this can be desired too.

[Spence]

Not many elements expand or stay the same when they cool but in any case the wax will shrink through the coil without drawing it in.

[NightWinder]

Hum...There is also different grades of paffifin with lower melting points too starting around 139 for a more purer grade- When cooling with just paraffin you'd think perhaps it stablizes the coil slightly different than with an additive. Just thinking out loud...

[mick]

Watch out for bees if you are using beeswax in the mix , had a swarm of them trying to invade my shed one day..must have been the nice smell ,

Mick

[texan]

Thanks for the info on wax potting. As a matter of fact the pickups worked fine when wired up in my guitar. Since I have heard that the Stew Mac covers are a little small for their pickup kits I will try another vendor for this part.

I can confirm that bees like the smell of melting beeswax. I was potting pickups on my back patio and the bees did swarm around the wax. I was concerned that a bee would land in the wax, but none did.

[corduroyew]

I read somewhere (think it was on MIMF) that beeswax can sometimes have chemicals that will corrode the wire over 15 or 20 years and that if you really want your pickups to last forever you shouldn't use it.

[Ruel]

I read somewhere (think it was on MIMF) that beeswax can sometimes have chemicals that will corrode the wire over 15 or 20 years and that if you really want your pickups to last forever you shouldn't use it.

The thread was posted here sometime ago.

[mick]

Hey Ruel , how have you been??

It depends on what the little worker bees have been gathering pollen from , some plants are quite acidic , some very alkaline , I use beeswax from bees that only gather from neutral plants in Switzerland ,so mine will be fine

Mick