Bare copper clamped to a galvanized object will "eat hell out of your pipes,"
to quote that apocryphal NBS letter to the guy who wanted to use hydrochloric
acid for drain cleaner. I use a few wraps of stainless steel shim stock from
the local industrial supplier for that purpose - and have found no galvanic
activity even after a dozen years of use.
I do not recommend exothermic welding, brazing, or any similar process on
tower legs. Or on anything else that's load bearing. If it's hot enough to melt
metal it will weaken the leg, and vaporize the galvanizing. That ain't good
when the wind blows and the rain is as acidic as lemonade.
Per Jerry's suggestion, I have seen a copper wash boiler buried for a ground.
And an antique 500 gallon copper stock tank as well. The hole for the wash
boiler was about the size of the hole for the privy and just as hard to dig.
The hole for the stock tank took three good size farm boys a couple of days to
dig by hand. Both made good grounds, although radio wasn't the real purpose of
the ground. If you are going to go that route, rent a back hoe.
But with the general availability of someone with Deep Rock well drilling
equipment in farming country you can usually ask at the CO-OP or farm supply
and
get a hole drilled for a serious ground rod, 4 to 6 inch steel pipe, down to
standing water for a couple of bucks a foot. The pipe's about the same price
per foot, and when you are done you have a ground system that won't break your
back putting it in, and won't quit when lightning strikes. Although the open
top of the pipe does tend to steam a bit after a heavy hit.
Here in the south, several State Highway Patrol's use that grounding system
on their towers, as well as cell phone companies and others who think their
equipment must stay on the air. I figure if it's good enough for the commercial
guys it's good enough for ham radio. And by the way, the XYL tells me my
tower was popped again today. No damage. But it sure scared the dogs.
73 Pete Allen AC5E
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