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Non-conducting permanent coating

I'm working on a new design and need to be able to apply a non-conductive coating to aluminum to insulate 12,000 volts. I thought a Teflon spray maybe like Cammie 2000 from AE Yale which I read here on a different post, however they seem to be out of business? I don't need any lubricating properties, but I do need the coating to be somewhat permanent. I also need the coating to be minimal thickness.

Mark Schreiber
Metal Fabricator - Minneapolis, Minnesota, USA


Your inquiry is quite vague, Mark, because we don't know what other properties the coating requires, if any, or the size of the parts. And when you say that you "need to be able to apply" we don't know whether you are limited to something that comes out of a spray can or you are able to install an automated metal finishing line or you would be willing to send the parts to a metal finishing shop.

Anodizing or application of insulative organic coatings are possibilities; if there is anything threatening about failure of the insulation, maybe anodizing plus an organic coating would be best. Can you give us some concrete details?

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

OK, color me a coward, but I have to seriously question 12,000 volts with a minimal thickness. While that minimal thickness may cope with it 99.9% of the time , is a tiny flaw or ding that allows a small amount (or large amount) of electricity acceptable for that 1 in a thousand or 1 in a million failure. Lawyers will have a feeding frenzy after the first failure.

James Watts
- Navarre, Florida

My specific needs are two fold. First, I need something inexpensive and easy to apply for a prototype, something in an aerosol spray can would be ideal. The parts are approximately 4" wide and 20" long. All surfaces are pretty much flat. The surfaces will be repeatedly exposed to water and detergent so the coating must not be able to wash off. For prototype purposes however, the parts will not be washed so it won't be necessary for the coating to be waterproof.

Secondly, if (when) the prototype is successful, I will need a long term solution. This could include sending plates out to be plated, anodized or otherwise coated, purchasing the raw material already coated (we punch out plates from coil aluminum now) or punching a new material possibly that is just plain inherently non-conductive (but that introduces a new host of problems).

Failures for this product would not be devastating. The current is very low (less than 4 milliamps). I've been hit by more than 20,000 volts while working on other prototypes repeatedly without so much as a sore shoulder. Pinhole leaks in the coating may not even be noticeable.

Mark Schreiber
- Minneapolis, Minnesota

OK, so it is a secret- How can you get much help that way? With what you have given, I will guess that a type II anodize, not sealed, air cured for one day and teflon applied by a professional in your area with the lowest possible cure temp. If this is a flat surface you might be able to get by with a UHMW tape. It can be cut to virtually any width. Quite durable and easily replaceable. Can be obtained in a variety of thickness and adhesive. Nearly as slippery as teflon, but the tape sticks very well when applied correctly. No cure time also. Talk to a 3M dealer about properties.

James Watts
- Navarre, Florida



I have a quite similar problem. I need a non-conductive coating for a filter mesh. The material of the mesh is stainless steel and the pore size is 75 µm. Thus the coating must be thiner than 20 µm in order to allow for fluid flow through the pores. Additionally, the surface of the filter mesh is not flat. It is like a woven fabric.

The mesh will be exposed to acidic and basic solutions (pH: 2 to 12) at room temperature.

It does not matter if small flaws occur in the coating.

To my understanding, ceramic coating is not suitable because it crumbles when the filter mesh is slightly bent.

Would Teflon spray be a solution?

Thank you for your help.

Bastian Schaefer
- Karlsruhe, Germany

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