Conductive paint ???
 

Anybody know of an easy to apply, low cost conductive paint ? I've been
able to find quite a few products that will work, but the costs involved are
VERY high for anything above a very small quantity. I've got a project i'm
working on that may require the use of a few gallons of this type of
product. Any and all help appreciated. Sean

Sorry I can't help with a specific recommendation. There are numerous
coatings available for EMI suppression, in spray form to be applied to
the insides of plastic enclosures. Various conductive materials are
offered at, I'm sure, a variety of prices. Unfortunately, I've let my
subscriptions to EMC trade publications lapse, so I don't have any up to
date ads to check. But you might try a web search for "conductive
coating", maybe with "EMI" or "EMC". It should turn up some possibilities.

I don't think most of these coatings are intended to be exposed to
weather, and they might not stick well to materials other than
thermoplastics. So without knowing your application, I don't know if
they'd be suitable. It's a place to start, though.

Roy Lewallen, W7EL

Sean wrote:
Anybody know of an easy to apply, low cost conductive paint ? I've been
able to find quite a few products that will work, but the costs involved are
VERY high for anything above a very small quantity. I've got a project i'm
working on that may require the use of a few gallons of this type of
product. Any and all help appreciated. Sean

Sean wrote:
"Any and all help appreciated."

Search on "spray-on zinc."

Zinc so applied can attain a thicknes of 10 thousandths of an inch. This
thicknness should be plenty at h-f, due to skin effect, for
conductivity. The zinc spray should be economical as it is used for
corrosion protection on large structures like bridges.

Best regards, Richard Harrison, KB5WZI

Roger, K8RI wrote:
"I`d check the stuff for conductivity before using much."

Good point. The more conductive it is, the narrower the stripe required
to give suffuicient conductivity for your application.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Roger, K8RI wrote:
"I`d check the stuff for conductivity before using much."

Good point. The more conductive it is, the narrower the stripe required
to give suffuicient conductivity for your application.

Also beware of the nickel-based EMI shielding paint which is magnetic
and *meant* to be lossy.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek

Ian, G3SEK wrote:
"Also beware of the nickel-based EM shielding paint which is magnetic
and "meant to be lossy".

Good idea.

Does nickel-based paint make an aircraft disappear from the radar? I`m
kidding but there are such paints and they should probably be avoided
too.

I advised the questioner to SEARCH on "spray-on zinc". Doing that
myself, there were many responses so the product must be popular. I saw
offers of combined zinc and aluminum.

Due to their places at the top of the electromotive series, aluminum and
magnesium may be considered more protective of steel than zinc. Metals
at the top of the series tend to pass into ionic form more readily than
metals lower in the series. The ions are formed by loss of electrons.

If aluminum is thought to give better protection, it`s probably not
surprising to see it offered in a protective coating. Aluminum is one of
the most abundant substances on earth, so its cost is likely reasonable
even though refining is not as cheap as some other metals.

I did not study the responses very long, but I don`t remember any
mention of nickel. If Ian says it is on the market, I believe it is
available and is to be avoided.

Best regards, Richard Harrison, KB5WZI