In a message dated 2/8/2006 3:01:07 AM Eastern Standard Time,
europa-list-digest@matronics.com writes:
Hi Fred,
> I don't see how conductive grease will solve or prevent any
> problem.
>
> Sure it does. Conductive grease enhances the conductivity of the connection
> and prevents oxidation down the road. Penetrox is used either between the lug
> and the buss bar or between the lug and the cable. A lug that is freshly
> crimped or recently installed on a buss bar generally doesn't need any
> conductivity enhancement, but 5-10 years down the road when corrosion sets up
between
> the cable and the lug or the lug and the buss bar it becomes very important.
> You only use a very thin layer of the Penetrox between the cable and the lug
> or the lug and the buss bar, so there is no need to worry about heating up
> the grease and having it run out. I've seen lugs on lightning protection
> systesm that took repeated direct lightning discharges on literally thousands
cell
> towers and I've never, ever seen Penetrox run out due to heating. Believe me,
> the lugs get very hot when they take a direct hit by lightning, particularly
> in Kentucky and Michigan where the ground resistance is high.
Small crimps get soldered to prevent oxidation. Large lugs are difficult to
solder, so
> Penetrox is used. This is industry standard.
I also put a piece of heat shrink over the crimped area of the lug. The shrink
> will help prevent oxidation and it makes the connection look better, too.
> I have seen quite a few battery cables fail on automobiles due to oxidation
> between the end lug and the cable, particularly on GM products. However, I
> have never once seen a cable connection fail when Penetrox or Al-Ox was used
in
> more than 7,000 cell site installations I've done over the past 19 years.
>
> In regard to not being able to Google up a specific application for Penetrox
> on aircraft, this does not surprise me in the least. As you are aware, we
> live in a very litigious society. Given the long and sorted history of
> aircraft
> liability in our court system, manufacturers who do not specifically produce
> products for aircraft use are usually very reluctant to say one way or the
> other if their products are applicable to use on an aircraft, particularly if
> that aircraft is experimental. I ran into this a while back when I made the
> mistake of telling a paint manufacturer that I was wanting to use their paint
> on an airplane. All I wanted to know was whether or not their paint provided
> adequate UV protection for the underlying composite. As soon as I mentioned
> aircraft, they stopped responding altogether. I appoached them again a few
> weeks later with a different e-mail address and mentioned fiberglass "boat"
> instead of fiberglass "aircraft" and they gave me all the info I could ever
> want
> about their paint products. As a result my fiberglass airplane, er, uh,
> "boat" is now white and shiny and has loads of UV protection.
>
> Regards,
>
> John Lawton
> Dunlap, TN
> A-245 (Engine installation complete, airframe complete, painted surfaces
> being hard waxed and buffed today while I await the return of FAA registration
> paperwork sent in NOVEMBER! Watch this space for a big announcement coming in
> a few weeks!)
>
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