Yes Eric, 

I have worked with conductive coatings on plastic with 
no problems as long as some things are kept in mind - 

There's a whole UL thing to it that I can list 
if enough people want me to.  

The coatings cannot withstand repeated removal 
from the product. The coatings are very fragile. 
Follow the basic rule of - "install the cover 
only when you know it's not going to be removed". 

I looked into nickel, copper, and silver. It seemed 
that nickel was half as conductive as copper and 
silver was more than twice conductive as copper. 
Price seemed to follow suit also. 

Shielding effectiveness totally dependent upon 
how well your vendor can control the thickness. 
Stay below 1 ohms/sq.  I forget how many mils 
that works out to be for nickel. 7 mils maybe? 

Observe the type of emulsion used for the specific 
metal used. Nickel conductive coating is not 
nickel conductive coating. There are at least 
two out there I found - one's basically a water 
based paint, the other is a sort of oil based paint. 
The oil base is obviously less conductive and that 
translates to a thicker coating needed to be applied  
and that translates to more paint - more cost. 

Don't use it for primary ground obviously. 

I also looked into conductive plastic coatings. 
At the bottom of it all, conductive plastic was twice 
as expensive as plastic with conductive coating. 

Regards,  Doug 

----------
> From: Eric Henning <[email protected]>
> To: [email protected]
> Subject: conductive coatings
> Date: Tuesday, February 24, 1998 3:53 PM
> 
> anybody have any opinions on conductive coatings on plastic for rfi/emi
> protection?  we've been very successful  at designing our products to
> be quiet and immune even in plastic boxes but i've been asked to 
> look into conductive coatings for further protection.  i've ordered some
> spray/brush on coatings but is it a waste of time? I was hoping to find
> spray can samples but haven't,  anybody know of 
> spray bomb coatings?  also looking into vacuum application. I guess
> i'd like to try spray/brush stuff first just to see if it makes any
> difference.
> 
> thanks
> 
> eric
> [email protected]

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