Good question, and I cop to repeating something I read on an anti-seize product
website. :-) Trouble is, I now can't find the site because I didn't bookmark
it. Unless or until I do find it, therefore, y'all may consider my paraphrased
admonition about "metallic particle wash-out and replacement by corrosive salts"
as BS. Which it may be anyway. :-) Thanks to Eric for challenging it. However,
I'm going to continue to look for the mystery site, and then at least we'll have
some real published assertions to debate.
I also checked one of my "Bible" sites for industrial materials, Loctite, and
found that their "marine grade" anti-seize product is in fact metal-free. It's
composed of petroleum grease, calcium oxide, graphite, and calcium stearate.
According to their anti-seize products brochure, "Formulated to protect
assemblies exposed directly or indirectly to fresh and salt water, Marine Grade
Anti-Seize works especially well in high humidity conditions. It has excellent
lubricity, superior water wash-out water spray resistance, and prevents galvanic
corrosion. ABS Approved." Elsewhere on their site, they recommend their
non-metallic anti-seize (they also make numerous metal-containing anti-seize
products) for marine and salt-air environment applications. For anyone
interested, this product is Loctite Marine Grade Anti-Seize, item numbers 34395
(8-oz) or 34026 (16-oz). I haven't checked extensively for retail outlets for
it, though McMaster-Carr doesn't carry it. They do carry a couple of other
non-metallic anti-seize compounds from other producers. I've just come to trust
Loctite products, because it's been my experience that they perform very well.
And Loctite's online technical reference library is really outstanding.
Bill / W5WVO
Eric Scace K3NA wrote:
> I am puzzled by the following assertion:
>
> "...If you live on the seashore and have a moisture/salt/wind
> condition continually battering your antenna, you have to be a lot
> more selective in your choice of anti-seize, because the moist salt
> air will, over time, wash the metal particle suspension (oftentimes
> copper) out of the anti-seize compound and replace it with corrosive
> salts, leaving the fasteners even more vulnerable
> to galling than if no anti-seize had been used in the first place. A
> non-metallic anti-seize compound (much harder to find at
> retail) is recommended for such environments..."
>
> What is the mechanism by which salt air/water penetrates the
> suspension, and converts its contents to a corrosive salt?
>
> I've used ordinary anti-seize compound on racing sailboats and not
> seen this at all.
>
> Perhaps this is being confused with galvanic corrosion of
> aluminum, when stainless steel hardware is used in a salt water
> environment without galvanic isolation? This corrosion pits the
> aluminum and generates a white, powdery material (some form of
> aluminum). Such galvanic corrosion can be reduced by placing a
> plastic washer between the stainless steel hardware (bolt head,
> ny-lock nut) and the aluminum surface. One needs to use a form of
> plastic that will resist deformation when the bolt is tightened.
>
> -- Eric K3NA
>
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
> "Wireless Weather Stations", and lot's more. Call Toll Free,
> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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