 DaDogsSemper VigilantisPremium
join:2004-02-28
Deltaville, VA | Wont Work! Been there done that (in reverse)...
Two or three years ago I was working on a wave guide design which required me to build the guide of plastic and use paint to cover the plastic and create the wave guide. Went to the local boat store and bought bottom paint. This stuff weighs like five pounds per quart there is so much copper in it.
Guess what... didn't work. Who would have thought that the paint used on the bottoms of boats and which cost about $20.00 per quart, wouldn't form a fine wave guide when applied to the correct diameter of plastic pipe?
Didn't work and unless these dipsticks have done something magical, still doesn't work.
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I'd rather chew sand than watch sixty seconds of 60 minutes. |
 jig
join:2001-01-05
Hacienda Heights, CA |
bottom paint isn't doped with copper to try to create a conductive layer, as far as i know, and so isn't quite the right product. what you wanted was completely connected (low resistance) layer of Cu that has no disconnected holes in it that were bigger than probably something like 1/4 the wavelength of the em wave you were guiding, and you probably wanted the whole thing grounded as well. i don't think boat paint would work for you.
the makeup of the shape of the particles is a big deal as far as resistance goes. i can't find any spec on the Cu particles in bottom paint, but the flakes of silver used in conductive silver epoxy are specifically ground (i think they're ground) that way to form a decent conductive film, even a reasonably thin one. the cheapest shapes of small particles of metal (probably what's in bottom paint) aren't the most conductive.
for this paint to work, it basically has to form a pretty well connected (conductively) MESH of copper, not a continuous layer, and the mesh has to have a statistically good chance of not having open sections that are big enought o let through the shielded (spec) waves.
could work. would have to test. rather than worry about the particle migrating over time, i'd seal it in with a top coat of something prettier.
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 totamakAnd they call me nuts?
join:2000-10-24
Los Angeles, CA | reply to DaDogs
Copper doped hull paint isn't using copper in the metallic form, but in a sulfite form. It's a biocide designed to keep barnacles and such from adhering to the hulls of boats. |
