Magnet insulation

[kevinT]

Hey Kevin did you tried the glyptal stuff, now this is what I use for insulating magnets, it works great for me.

oopps didn't see this post until now.....I bought 2 small cans a while ago and they are sitting under my bench. I just haven't had a chance to work on my single coils because i'm focusing on my humbucker models. I am going to try it out for sure and i will let you know how it goes. I just don't know when.

[rjb]

Don't step on the...

I thought I'd throw this out there and see what washes up on shore....
Its has to be a hard almost invisible finish , hard as super glue, be easily wiped off and not thick so you don't have crap all over the magnet tops and flatwork.

Sometimes it takes a while for stuff to wash up on shore.

I know this doesn't meet Possum's criteria, but might be useful for other applications:

Has anyone ever tried Porc-a-Fix Porcelain Touch-Up Glaze?
It's a brush-on enamel that looks a lot like the stuff DeArmond-Rowe used on the inside of their BackPlate/BobbinFlanges.
It might (or might not) be tougher than marine varnish- I couldn't find any data, and haven't done my own A/B testing.
It is pretty thick, but can be thinned with mineral spirits.
You can get it in a rainbow of colors- but not clear.




Later,
-rb

PS: Possum, could you relieve your anxiety about getting crap on the magnet tops and flatwork by coating the magnets before assembly?

[Possum]

I abandoned the idea of insulating magnets years ago. I've only seen it done in very early Gibson pickups like P13's, basically the gains from doing it are so minimal its not really worth the effort....

[rjb]

I abandoned the idea of insulating magnets years ago...basically the gains from doing it are so minimal its not really worth the effort....

Thanks, Possum. You just saved me some "really not worth the" effort.


PS:
Going back to my "insulating backplates used as bobbin flanges" sidetrack,
this spray paint might be better than Porc-a-Fix: Rust-Oleum Specialty Appliance Epoxy.

The label says "APPLIANCE EPOXY is an ultra-hard, moisture resistant enamel that is specifically formulated for indoor metal surfaces."
The directions say priming is NOT recommended.

I was going to try some on a magnet, but Possum just talked me out of it.

-rb

"To the boy with a hammer, the whole world looks like a nail."

[Joe Gwinn]

Going back to my "insulating backplates used as bobbin flanges" sidetrack,
this spray paint might be better than Porc-a-Fix: Rust-Oleum Specialty Appliance Epoxy.

The label says "APPLIANCE EPOXY is an ultra-hard, moisture resistant enamel that is specifically formulated for indoor metal surfaces."
The directions say priming is NOT recommended.

I was going to try some on a magnet, but Possum just talked me out of it.

Note that this does not suggest that one should wind directly on the magnet, only that varnish et al either don't work (film too soft) or take too long to cure.

The standard alternative is to tape the magnet before winding, using a hard enough tape that the windings won't swim through the tape over time.

[big_teee]

Note that this does not suggest that one should wind directly on the magnet, only that varnish et al either don't work (film too soft) or take too long to cure.

The standard alternative is to tape the magnet before winding, using a hard enough tape that the windings won't swim through the tape over time.

Most of us do both.
I spray the flatwork with krylon clear, to help lock the magnets to the forbon.
I let dry over something warm.
Then I use a layer of thin tape.
I have not had a single problem since I started doing this.
Terry

[rjb]

Note that this does not suggest that one should wind directly on the magnet, only that varnish et al either don't work (film too soft) or take too long to cure.

The standard alternative is to tape the magnet before winding, using a hard enough tape that the windings won't swim through the tape over time.

I had figured on using both spray enamel and cloth tape- sort of a belt and suspenders approach.

This would be for that "Eye-Beam" magnet we're discussing in another thread. Since the pickup apparently failed due to magnet corrosion, I thought it might behoove me to coat the magnet. But I'm going to pot the pickup ("historically correct" restoration be damned) and hope the wax will keep the pitty crust monsters at bay.

Thanks,
-rb


PS -
Dry times for the Rust-Oleum Appliance Epoxy (@70F, 50%RH)
Dries to touch: 2-4 hrs
To handle: 5-9 hrs
Fully dry: 24 hrs
May recoat within 1/2 hr or after 1 week

[Joe Gwinn]

I had figured on using both spray enamel and cloth tape- sort of a belt and suspenders approach.

I don't recall that anyone else was using cloth tape on the magnet, under the winding, but it's a plausible approach. This general area has been heavily discussed, and it's all in the archive.

This would be for that "Eye-Beam" magnet we're discussing in another thread. Since the pickup apparently failed due to magnet corrosion, I thought it might behoove me to coat the magnet. But I'm going to pot the pickup ("historically correct" restoration be damned) and hope the wax will keep the pitty crust monsters at bay.

I would not trust the potting wax to prevent rust. This too has been extensively discussed.

Dry times for the Rust-Oleum Appliance Epoxy (@70F, 50%RH)
Dries to touch: 2-4 hrs
To handle: 5-9 hrs
Fully dry: 24 hrs
May recoat within 1/2 hr or after 1 week

Most coatings cure quicker and harder if cured in an oven. One typical recipe is to air dry until it can be handled, then finish in the oven. An old toaster oven set to Warm can be used. (Do not use for food afterwards.)

[rjb]

I don't recall that anyone else was using cloth tape on the magnet, under the winding, but it's a plausible approach. This general area has been heavily discussed, and it's all in the archive.

The Electromuse Eye-Beam pickup used white cloth tape on the magnet.

I would not trust the potting wax to prevent rust. This too has been extensively discussed.

Oh, well- I've already started rewinding the Eye-Beam. My "spray booth" is the great outdoors, and between the high temps, humidity, wind and thunderstorms, I gave up on finding a window of opportunity. But I won't be any worse off than with the original- which appears to have been potted in beer.

Most coatings cure quicker and harder if cured in an oven. One typical recipe is to air dry until it can be handled, then finish in the oven. An old toaster oven set to Warm can be used. (Do not use for food afterwards.)

Maybe my S.O. would allow me to use her "polymer clay curing oven" (an overpriced toaster oven, silkscreened with p.c.-specific settings).

Thanks, Joe.
-rb

[big_teee]

Most of these old rusty pickups took 30+ years of Hot Sweaty, Smokey night clubs to get that way.
So maybe your pickup just wax potted will get another 25-30 Year run.
Terry

[belwar]

I found a product by behlen called Rock Hard Tabletop Varnish. Looks like it might work really well. Im going to dip bobbin in some form of degreasing agent first (maybe prosolve or acetone), then after its totally dry i'll put a drop of CA on each magnet base, and double dip the bobbin in 50% reduced varnish. I have the luxury of time so i'll let it sit for a week or so in a hot area to flash off. I'll report back

[rjb]

Since the pickup apparently failed due to magnet corrosion, I thought it might behoove me to coat the magnet. But I'm going to pot the pickup ("historically correct" restoration be damned) and hope the wax will keep the pitty crust monsters at bay.

To anyone suffering nightmares of crusty EyeBeams:
I had experimented with several coatings, and forgot I last sprayed the magnet with Rust-Oleum Painter's Touch Ultra Cover 2X Clear Gloss.
So the magnet is coated. You can go to sleep now.

-rb

[rjb]

I abandoned the idea of insulating magnets years ago.

So, you solved the problem of coil shorting to end poles? Or was it that you wanted to use insulation instead of tape... I may have misread the OP.

-rb