[TowerTalk] getting the ufer ground effect with a burried painted section

[Roger (K8RI) on TT]

As a personal opinion and many years of back ground I think the bare 
metal would be better. The question is "how much better?"  It depends on 
the area of painted metal in the concrete and that depends much on the 
size of the tower legs. The metal with pain is essentially a very large 
capacitor that will shunt most of the lightning strike to the UFER 
(concrete) and that concrete has a tremendous area on the exterior. Far 
more than a network of ground rods.
It would take a very powerful strike to even damage the paint.

Jim Brown gave a very good description of the voltages, currents and 
power involved.

Were it me, I'd add a ground rod out about 6" on ea side (in the 
concrete) from each tower leg in addition to an external ring of ground 
rods extending out for two 8 footers, 16' apart..

As to rust. I doubt that would be a problem "in" the concrete.  I would 
want the top 4 to 6" where it enters the concrete painted though.  There 
is a high tendency to rust where unpainted steel enters the concrete.  .

73, Roger (K8RI)


On 9/6/2017 Wednesday 12:55 PM, Jeff AC0C wrote:
> I’m pouring concrete for a tower base using a bottom section standing on gravel in the hole.  I had assumed that would prove some UFER ground benefit but wanted to ask because before placing the section into the hole it was painted well with the Rustoleum cold galvanizing paint.
>
> I hope that I have not voided my ufer ground effect with the application of the paint.  Because here in the Midwest, lightning is definitely going to be a problem faced sooner than tower corrosion.
>
> 73/jeff/ac0c
> www.ac0c.com
> alpha-charlie-zero-charlie
>
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-- 

73

Roger (K8RI)


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