Ultraperm sheet for sale

[Joe Gwinn]

The product description tells it all: SALE! Rare Ultraperm 80 Shielding Sheet-The Electronic Goldmine.

One can see if it matters in a pickup for small dollars, $6 per sheet.

Electronic Goldmine is a respected seller of random electronics stuff, mostly surplus.

[David King]

Is it true that sharp bends in this material will destroy it's magnetic properties? I'm trying to figure out how it could be used in a stacked pickup..

[belwar]

So where would you use something like, and how would it differ from a coating like super shield?

[David Schwab]

It's shields you from magnetic fields. Super Shield shields you from electric fields.

Ultraperm 80 sheet is a nickel-iron alloy (80.3% nickel, 14.3% iron, plus 14.3 %molybdenum). It has very high magnetic permeability (400000 @ 0.73-0.5mm -50Hz maximal permability) which makes Ultraperm 80 very effective at screening static or low-frequency magnetic fields which are difficult to attenuate with other means.The Ultraperm 80 is similiar to Mu-metal but the copper which is added to make Mu metal more ductile is not added to this sheet. This shielding is commonly found around transformers in high end audio equipment, cathode ray tubes in oscilloscopes, photomultipliers, magnetic phono cartridges, hard drives, super conducting circuits, MRI equipment, etc. This is a difficult item to find for the average hobbyist.

[Jag]

I saw a video demonstrating the effect of using Mu-Metal to sheild a wha pedal from the the effect of a nearby power supply. It was amazing how much the sheild reduced the noise! Since this seems to compare to the Mu-Metal, I'm thinking of buying a sheet to try out. I've got my wha as far from my power supply as possible but, a pedalboard can only be so big and the wha is still a little noisier than I'd like. Of course, batteries kill the noise all together but, that gets expensive and not all my pedals can run off batteries.

[Joe Gwinn]

Is it true that sharp bends in this material will destroy it's magnetic properties? I'm trying to figure out how it could be used in a stacked pickup..

It's mu metal that's famous for strain sensitivity, but the ultraperm description sounds like it isn't that affected, perhaps due to the fact that the sheet is quite thin. One can cut the sheet with ordinary steel scissors, if they are sharp. For this price, I would just try it.

[David King]

Thanks Joe, sounds like a plan.
To shield a magnetic field does the shield have to be grounded? I.e. do I have to solder to this stuff along the way?

Speaking of MG Supershield, I've figured out that it's actually nickel plated iron filings, not pure nickel. If it were pure nickel the price would be 3 or 4 times higher. All that iron really messes with magnetic fields so best to keep it away from pickups.

[belwar]

Thats instresting about the super shield! I thought about doing the pickup cavities on my P-90 guitars, but laziness stopped me. Now im glad I didnt.

I have to say that my cavities have never looked better. A customer of my took his guitar to a tech recently and told him the cavity was a work of art.

So a thank you to Joe for recommending that product!

bel

[Joe Gwinn]

Thanks Joe, sounds like a plan.
To shield a magnetic field does the shield have to be grounded? I.e. do I have to solder to this stuff along the way?

A magnetic shield need not be grounded, but it's still a piece of metal and if grounded will also act as an electrostatic shield.

One can certainly solder to ultraperm, but it may require some kind of acid flux, at least initially.

Speaking of MG Supershield, I've figured out that it's actually nickel plated iron filings, not pure nickel. If it were pure nickel the price would be 3 or 4 times higher. All that iron really messes with magnetic fields so best to keep it away from pickups.

There is no iron in MG supershield, according to the MSDS. The metal is pure nickel.

I doubt that the ferromagnetism of the nickel in supershield has much effect, as these are small particles with lots of non-ferrous material between.

[David King]

Interesting, I never thought to look at the msds. Well all I can tell you is that I was using it to shield inside my pu covers and it was completely killing my treble even after I cut all the corners to prevent eddy currents. It must be the nickel that's deflecting the field just enough.

[David Schwab]

For this price, I would just try it.

This looks very interesting, but I'd hate to use it and love it, and then not be able to get anymore at a price I can afford.

[Joe Gwinn]

Interesting, I never thought to look at the msds. Well all I can tell you is that I was using it to shield inside my pu covers and it was completely killing my treble even after I cut all the corners to prevent eddy currents.

What's the capacitance between cover and coil?

Cutting only the corners may not reduce eddy currents enough, although I would have thought the sheet resistance (about 10 ohms) of the dried shield paint would pretty much abolish the eddy currents even without any cuts.

It must be the nickel that's deflecting the field just enough.

I would play with the cover (off the pickup) and a magnet. How strong is the magnetic effect?

[Joe Gwinn]

This looks very interesting, but I'd hate to use it and love it, and then not be able to get anymore at a price I can afford.

It will answer a science question for sure. And if it doesn't really work, then no need to dig deeper.

[David Schwab]

It will answer a science question for sure. And if it doesn't really work, then no need to dig deeper.

Very true. Do you have any idea where to buy this stuff other from the link above?

[Joe Gwinn]

Very true. Do you have any idea where to buy this stuff other from the link above?

I've never tried to buy the stuff, but it is available. There seem to be lots of offers on eBay. The makers I know of are Vacuumschmelze in Germany, and multiple places in China. Armco Steel may also be a US maker.

VAC > ULTRAPERM