Re: MG Shielding Spray

["Tesla list" <tesla@xxxxxxxxxx>]

On Fri, 14 Sep 2007, Teslacoil Workshop wrote:

> TCML,
> 
> This thread appeared on my robotic airplane forum and I thought the
> information might be useful to Tesla coiling applications.
> 
> Jeff Parisse
> 
> Quote:
> 
> Hey guys,
> 
> I found this thread on our hit report today so I thought I'd check it
> out.
> 
> I'm the guy that formulated our 841 Super Shield Conductive Nickel
> coating, so anything you want to know, just ask.
> 
> The product is pretty much just high purity conductive nickel flake in
> an acrylic lacquer formula that was originally intended for use on
> wood.
> 
> As to what is superior between this coating and a conductive tape,
> well I think tape is less costly but more of a pain to apply properly.
> 
> Also, copper tape is of course going to block different frequencies
> then a nickel coating. Each metal has it's own absorption profile and
> most products made for shielding should have a graph available that
> shows which frequencies the product is good at shielding. Certain
> metals and pigments are better then others certain applications. It
> depends what frequencies are bothering your device (I'd suggest not
> trusting products that list a shielding effectiveness in dB without
> listing a frequency).
> 
> We have a graph that compares the effectiveness of our paint with
> different pigments here:  
> http://www.mgchemicals.com/products...-841shield.html
> 
> Nickel pigments have an advantage over silver and copper pigments in
> that nickel blocks both the magnetic and electrical components of EM
> radiation, whereas the others only block the electrical component.
> 
> Where this product excels is if you have a plastic electronic
> enclosure. You just spray the inside and it's good to go in 10
> minutes.
> 
> A lot of times companies develop a product and are just about ready to
> go to market and then realize at the last moment that there's such a
> thing as FCC standards and they have to shield their product before
> they can sell it. This product is really good for that sort of
> situation, because they can just spray the insides of the enclosures
> and they are good for their first few production runs, which gives
> them time to come up with a less costly alternative, like metal shells
> or mesh.
> 
> We sell a lot of this product in liquid form for large production runs
> in China, but the aerosol can does very well in North America, because
> it allows small manufacturers and hobbyists to be able to apply the
> paint without having to obtain proper spray equipment. I'm not sure if
> anyone else is offering a spray in aerosol form these days or not. GC
> used to sell a carbon based one in aerosol, but I think they deleted
> it. I'm not sure about that though.
> 
> This product is used on the inside of a lot of cell phones and pda's.
> 
> As for it flaking and dropping into your circuit, I've never ever
> heard of that happening. I'm sure someone would have called me trying
> to get money for killing their expensive electronics if that ever
> happened, and nobody has tried that yet.
> 
> The product is UL approved for adhesion to ABS plastic and
> polycarbonate plastic at both hot and cold temperatures, and part of
> that test includes abrasion tests.
> 
> The product will not adhere to glass, and will have issues if you are
> trying to apply to porous surfaces, or very chemically resistant
> surfaces. It will adhere to metal, wood, and plastics.
> 
> We use this same acrylic base for our Acrylic Conformal Coating,
> because it's super tough, durable, and moisture resistant.
> 
> That said, most of your tougher acrylics require Toluene in the
> formula in order to get the resin to break down, and our product is no
> different. Toluene is a prop 65 chemical, "known to the state of
> California to be reproductively toxic", so you want excellent
> ventilation when spraying this product. If you just have one device to
> shield, just spray it outside, stand upwind, and you will be fine.
> Just don't spray it in your eye
> 
> When working in an enclosed space, a half mask respirator with an
> organic vapor cartridge will control the hazard, or a good fume hood
> is another option.
> 
> One important point about this product is that when you are done using
> it for the day, you must turn the can upside down and press the
> button, spraying until you just get clear propellant coming out ( this
> will only take a second). This clears the paint out of the valve. If
> you don't do that, then the nickel flakes can possibly jam the valve
> open, and over night the rest of the paint might bubble out of the
> can.
> 
> Howard Clark
> President
> MG Chemicals