Magnet insulation

[EtLa]

what I do is I clean the magnets with a mix of water/degreaser and when dry I dip the magnet in Varathane Diamond Water-Based Polyurethane and suspend it for 8 hours. Works perfectly well for me.

[Zhangliqun]

Or you could just assemble the bobbin and then just wrap the rods in tape.

[David King]

I'd think super glue is the quickest and cheapest coating one could apply. It's very tough if it gets good adhesion. Harder finish would be a two part polyester finish but you really don't want to get into that unless you already use it for guitar finish.
There is a low oder cyano acrylate glue available at most hobby shops.
Check out http://www2.towerhobbies.com/cgi-bin...?&I=LXM365&P=7

Hot stuff UFO thin. (UFO stands for user friendly oderless).

I'd apply it by dipping each magnet in the bottle, (after degreasing), let it drain and set it on a sheet of slick plastic to dry. You could also squirt it on the assembled bobbin.

Why not slide thin tubing over each magnet??

[mick]

I would be more inclined to dip the whole lot into something rather than just the mags ,it sort of holds the bobbin together too so it's about more than just stopping shorting . Just finding the right dipping agent that's tricky....

Mick

[Spence]

I'd think super glue is the quickest and cheapest coating one could apply. It's very tough if it gets good adhesion. Harder finish would be a two part polyester finish but you really don't want to get into that unless you already use it for guitar finish.
There is a low oder cyano acrylate glue available at most hobby shops.
Check out http://www2.towerhobbies.com/cgi-bin...?&I=LXM365&P=7

Hot stuff UFO thin. (UFO stands for user friendly oderless).

I'd apply it by dipping each magnet in the bottle, (after degreasing), let it drain and set it on a sheet of slick plastic to dry. You could also squirt it on the assembled bobbin.

Why not slide thin tubing over each magnet??

With respect David, that's not a good solution for anyone trying to turn pickups out quickly. As I mentioned, the use of reducing punches reduced the hole diameter. Just a couple of hammer blows.

[David Schwab]

I think dipping the bobbin in something is more work than taping it. I just cut some strips of tape with a ruler and razor blade and wrap it around the poles.

I wonder if one reason for the shorts is the wire heating up as it's wound and melting through what ever protective coating might be on the magnets?

[David King]

Spence,
As brilliant as the reducing punches are I don't see how they would do much to insulate the magnets.

I think the cheapest, fastest and easiest dip would probably be shellac. It's low tox and reversable. A blond shellac like Zinzer Bullseye is pretty damn tough and the stuff will dry in minutes.

[Spence]

Well of course they don't. But they do reduce the hole that you hammer the magnets into. This is pre-lacquering. Obviously I didn't make myself clear enough. The idea of reducing the holes in the flatwork is so that the magnets have a tighter fit and therefore are less prone to move when winding and hence trapping the wire between flatwork and magnet. ( ...and breath...)
This sytem works. Even so, on some pickups I will reduce, lacquer and tape. Just do whatever is required but there's no need to get DuPont to develop a special coating for you etc....

[Zhangliqun]

I think dipping the bobbin in something is more work than taping it. I just cut some strips of tape with a ruler and razor blade and wrap it around the poles.

Ah, a fellow taper. I was waiting to get flamed over it -- but I suppose the thread is still young...

I wonder if one reason for the shorts is the wire heating up as it's wound and melting through what ever protective coating might be on the magnets?

It doesn't get THAT hot, does it? If it did, I would think the insulation would also melt from one layer to the next, especially on the ends where the turns are really packed tight together. Plus I would think the magnets themselves would act as a heat sink.

I've heard it kicked around that it's a slow chemical-ish reaction between the Alnico and the insulation that eats away at it. Sounds more plausible to me, but I'm hardly an expert on such things so I don't know.

[David Schwab]

Ah, a fellow taper. I was waiting to get flamed over it -- but I suppose the thread is still young...

I don't wind any kind of vintage recreation, so it's ok.

I've used scotch tape, electrical tape, and white paper tape, depending on my mood. In my case I'm winding onto a steel bar, who's square edges have been ground and sanded, but I'd rather be safe than sorry!

I do see where taping magnets will add some space between the wire and the magnet, so that might change something.

It doesn't get THAT hot, does it?

Probably not... I was thinking out loud.

[Possum]

results so far....

shellac sounds like a good try, the lacquer sanding stuff failed the ohmeter probe test, it was real easy to dig through it just like other lacquers so I know it'll short out, at least the way I wind. Nothing wrong with taping but the tape stops wax from entering the inside of the coil, what real effect that has I don't know, but I am trying to be more vintage correct and tired of taping. I think the UFO super glue sounds like a real good bet, the best I've heard here so far, I'm ordering some. Will try shellac this weekend....

[David King]

Shellac usually won't be as hard as most lacquers. What about a baked-on transformer varnish or even a powder coat? If you need it that tough you'll have a tough time finding something that isn't catalyzed in some way. Bake-on finishes or epoxy are less trouble because you won't be dealing with HAPs.
Just because that super glue is odorless doesn't mean the fumes won't kill you.

[Spence]

Taping Poles

Sounds like Police interrogation of eastern Europeans I know but just to be serious for a minute:

Fender also taped the poles for a short period. Concerns about wax not penetrating the inside of the coil did not come into it because they were lacquering the coil by then. Some winders like Wizard poke holes in the tape between the magnets to allow a free flow of wax. But if you have to resort to using tape, you only need use it on the outer poles.

[EtLa]

I use Water-Based Polyurethane that leave a thin finish and insulate pretty well, I suspend 6 magnets and at the end a dripping point that I made out of a 3/16" rod
http://www.rustoleum.com/product.asp...t_id=663&SBL=1

[Joe Gwinn]

shellac sounds like a good try, the lacquer sanding stuff failed the ohmeter probe test, it was real easy to dig through it just like other lacquers so I know it'll short out, at least the way I wind.

I think sanding sealers are as a class going to be soft, by design.

Lacquers are expected to be hard, but some take weeks to fully dry, unless one cures them in an oven.

Nothing wrong with taping but the tape stops wax from entering the inside of the coil, what real effect that has I don't know, but I am trying to be more vintage correct and tired of taping.

Does vintage allow for an extra pair of holes in the bottom flatwork to let the wax in?