Wax Potting Your Mosrite Pickups; A Tutorial

[oipunkguy]

As most of you know Semie never wax potted his pickups. many older pickups weren't. Epiphone didn't, some of the earliest fender pickups were coated in lacquer. well, here's a how to tutorial on how to wax pot your old mosrite pickups, of any pickup for that matter. don't be nervous, this is much easier then it sounds.

things you will need.

screwdriver
pencil style solder gun (no stronger then a 40 watt gun)
small pair of wire cutters.
solder
plastic thongs
thermometer
metal pot
stove
wax (paraffin wax or unscented white candle wax is best)

**when choosing a wax, you don't have to be too picky. just try to stay away from any colored wax, or scented wax. this is because you don't want any oils getting on the exposed coils and oxidizing the copper wrappings**.

1. first, you have to removing the pickups. I would recommend removing the pick guard first and making a detailed drawing of where all the wires go. remember mosrite pickups wires are very thin, so be careful not to break them.

2. once you have a drawing made, make sure you go threw the drawings a couple times to make sure you have the schematics drawn correctly. this will be the hardest part of this project.

3. next is removing the the pickup wires from the other electronics. make sure that you cut the wires as close to the other electronics as possible, so you have enough slack when you reinstall them. remember, don't be nervous.

4. next is removing the pickups (assuming you have already removed your strings). carefully unscrew the pickups from the pickup rings, then unscrew the pickup rings from the guitar. GENTLY pull the lead wires threw the drilled holes in the pickups cavities, paying close attention what wires run where. stop and write it down on your schematics if you feel it's necessary. most mosrite pickups are going to be a two conductor wire, where as mine are the mosrite humbuckers, 4 conductor, plus ground. on my mosrites, there's a separate hole drilled for the ground wire.

5. once the pickups are removed, sit them a side someplace safe, making sure you know which pickup is the neck pickups, and bridge. label them if necessary.

6. now here comes the fun part. the pot you are going to use probably should not be your wife's favorite cooking pot, try to use an old beat up one. next is melting down the wax. you will need enough wax to totally submerge the pickups, WITHOUT letting the pickup touch any of the sides of the pot. this is because the sides will be hotter then the wax itself. I would recommend at least 3 inches of wax when totally melted.
**PRS puts marbles all along the bottom of their pots to prevent any pickups touching the bottom of the pot. feel free to do this if you feel it's necessary.**

7. now you are going to melt down your wax. if really doesn't matter how hot you melt the wax, but it's VERY important to keep the wax lower then 130 degrees when the pickups are submerged to prevent any damage to the pickup. I would recommend 110-120 degrees.
** important note, don't remove the pickup pole pieces/screws before submerging the pickup**

8. once the right temperate is maintained, using the plastic tongs, submerge a pickup and hold it in the center of the pot. you will want to do this one pickup at a time. you will notice that you will see air bubbles come up as the wax fills into the pickup. try to shift the pickup around in different directions to make sure wax fills all of the pickup cavity. this should only take 5 minutes or less per pickup.

9. once you see that there is no more air bubbles coming up, you can remove the pickups and lay them down on something to dry. I suggest a paper plate.

10. wait a least a good 20-30 minutes for the wax to completely cool before handling the pickups.

11. using a soft cloth or paper towel gently rub off all the outside wax. pay close attention to the wax inside the screws of the pickups.

12. now you just need to reinstall the pickups, first attach the pickups to the pickup rings, then gently pull the wires back threw the holes to the guitar cavity. then screwing in the pickups to the guitar.

13. now resolder the pickups, check your work and you are done!! you will notice that not only is the microphonic squeal is gone, but the pickup should be quieter in general.

I was at first nervous of doing this project on my mosrites, but I much happier with my sound since doing this job. and you'd be surprised how easy it really is. if anyone have any questions, feel free to ask me here, or at my email addy oipunkguy@aol.com. if you want me to wax your pickups for you, I'll be happy to do it.
cheers all,
Aaron

PS. here's a schematic I found on Seymour Duncan's website to help you all out. this is for humbuckers, not p-90's but still will work. this is the most commend mosrite wiring, 2 p-90's, one volume, one tone, three way toggle.

Click the schematic for a printer-friendly version.
http://www.seymourduncan.com/pdfs/suppo ... _1t_3w.pdf

[oipunkguy]

http://www.seymourduncan.com/pdfs/suppo ... _1t_3w.pdf

[Mr. Bill]

One warning here, is that wax is flammable. It should not be heated directly on a stove, but should be melted in a water bath.

I use a small disposable aluminum pan that's approx 3" x 5" x 3" deep. I sit this into the wife's favorite sauce pan that's half filled with water. If you let the wax harden in the aluminum pan when you're done there is no cleanup to do.

[oipunkguy]

good point. yeah i should have mentioned that you should use another pot filled with water. i have since switched to using the stove to an electric heater made by Revlon. it's an oval shaped container for dry skin wax treatments for your hands. this makes the job a lot easier, because you can reuse the left over wax over and over again, and it won't overheat or catch on fire. safer, cleaner, and more practical.
I stole mine from my wife, lol.

[dubtrub]

I know it's a fairly simple process to wax pot single coil pickups such as on a Fender Strat, but Mosrite pickups are sealed not only in a foam but also and epoxy resin. How do you access the coils to seal them in wax?

I have no experience with the MIJ Mosrite pickups, but the one ones on my originals 60's and the ones I purchased from Ed Elliot are encased in a foam, unknown if the coils are wax potted. I do know that the Hallmark 60's (Mosrite clone) pups are already wax potted as I opened one up and examined it.

Here's a view of the bottom side of the current Elliot Mosrite pickup's.


By dubtrub

[oipunkguy]

this doesn't matter. in the case of a mosrite pickup, you leave the pickup cover on. the hot wax will find it's way in the pickup. you just want to move the pickup around just enough to let air pockets out. when I did mine all the air came up threw the pole pieces, but you want to keep the pole pieces in when dipping the pickup in the wax.

[MWaldorf]

So, what is the perceived advantage of wax potting here? I know it reduces squeal, but doesn't it change the tone? I wonder if it's like the "noiseless" pickups that are quiet but don't sound as lively, likely because they are noiseless. I've played my non-wax potted Fenders and Mosrites through my Showman at pretty loud volumes with no squeal issues.

[oipunkguy]

to my ear there's no change in tone, just a lot less microphonic feedback, noise, and hum. wax potting will not turn a single coil into a noiseless pickup, but if you have a non potted pickup that's giving you noise isses, single coil or hum cancelling, this will certainly help.
I play with a lot of high gain, and that's where you will get the most microphonic feedback issues, but you can get them also with clean tones.

[Mr. Bill]

Quite a few years ago, I had to rewind an original Mosrite pickup from a mid-sixties (I think) Combo.

In working on the pickup, I know that it was not waxed or otherwise potted.

The epoxy and foam base is not attached to the cover. I believe that the pole piece screws are the only thing that holds the covers on.

The bobbin was made of clear plastic top and bottom plates with a center wood spacer.

As for waxing, I'd say be very careful when waxing any plastic pickup parts (this applies to typical humbucker coils too). If the wax is hotter than the melting point of the plastic, you risk permanent damage to the pickup.

I know that some of the early Mosrite pickup covers were thermoformed and not injection molded like the later ones, so I would be especially wary of overheating these.

As for waxing pickups with the covers on, this is fine, but the wax will fill in all of the voids between the cover and the coil. If a repair is needed in the future, it will make disassembly of the pickup extremely difficult.

[oipunkguy]

Quite a few years ago, I had to rewind an original Mosrite pickup from a mid-sixties (I think) Combo.

In working on the pickup, I know that it was not waxed or otherwise potted.

The epoxy and foam base is not attached to the cover. I believe that the pole piece screws are the only thing that holds the covers on.

The bobbin was made of clear plastic top and bottom plates with a center wood spacer.

As for waxing, I'd say be very careful when waxing any plastic pickup parts (this applies to typical humbucker coils too). If the wax is hotter than the melting point of the plastic, you risk permanent damage to the pickup.

I know that some of the early Mosrite pickup covers were thermoformed and not injection molded like the later ones, so I would be especially wary of overheating these.

As for waxing pickups with the covers on, this is fine, but the wax will fill in all of the voids between the cover and the coil. If a repair is needed in the future, it will make disassembly of the pickup extremely difficult.

this is why is in very important to keep temperatures below 130 degrees Fahrenheit. also one major reason wax was chosen for potting pickups in the first place was because it's easier to remove the wax then dried lacquer to work on a pickup. lacquer being one of the first products being used on some of the earliest fender pickups. semie made the plastic molding of his very first pickups in his kitchen stove, so there shouldn't be an damage to the pickup at temperates of 130 degrees and below.
however, if anyone is too nervous to do this project, then someone just shouldn't do it. remember you can always buy a replacement pickup to experiment on, but it's much harder to replace an original mosrite pickup. my pickups that I potted was from the early 70's, I think if I had an early mosrite (65 or older) I wouldn't mess with anything. just my 2 cents.
cheers all,
Aaron