[TowerTalk] Exothermic Welding

[ersmar@comcast.net]

Warren:

     The key to what your electrician friend said is <I have used this process to weld bonding wires to  steel columns in high rise buildings.>   Amateur towers are not made from thick steel members like building steel columns, but from thin wall tubing.  You would probably damage the structural integrity of a typical ham tower by using Cadweld or other exothermic process to attach ground wires to the tower members.  The heat would destroy the mechanical strength of the member at the joint.  

     I suggest you use a SS clamp for these connections, as you had planned.  You will have to ensure that the copper ground wires (assuming you're using copper) do not come into direct contact with the aluminum of the tower legs.  I believe Champion Radio Products sells SS hose clamps that have a SS tab that hold the copper ground wire against the rest of the SS hose clamp, and not directly onto the tower member. 

GL es 73 de
Gene Smar  AD3F



>  
> Greetings  TTalkers,
>  
> I going to purchase wet stamped drawings for an AN  Wireless Tower topped by 
> a pair of
> OptiBeams.  My grounding plan has been  discussed by my home 
> designer/architect with
> the City Engineer.  I had noted that I would  probably use stainless steel 
> clamps to connect
> my radial field to the base of the tower.  My  electrician commented as below:
>  
> "Warren,
>      I have been reading  your emails and just wanted you to know that 
> exothermic
>      welding CAN join  copper to steel and aluminum. I have used this process 
> to
>      weld bonding wires to  steel columns in high rise buildings.
> /s/"
>  
> I am no master chemist, but I thought that exothermic welding  actually
> melted/bonded the copper into one integral mass.  Seems to me  that
> what he has done, as stated, is to just create a mass of copper stuck
> very tightly to some steel/aluminum tower which would sooner or later
> deteriorate.
>  
> Comments please,
>  
> Warren; W5KKW
> 
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> 
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