[TowerTalk] Cadweld vs other welds or brazing

[Roger (K8RI) on TT]

On 4/26/2014 1:00 PM, Warren Wolff via TowerTalk wrote:
>   My Tower guy wants to CadWeld my copper to the
> legs of my AN Wireless tower.  This worries me.

I'd pass on CadWelding directly to tower legs. CadWelding melts a goof 
portion of the base metal and alloys it with the copper and the Aluminum 
in the CadWeldinf material.  It makes a very good electrical joint, but 
would severely weeked the portion to the legs that is melted. It also 
heats quie ab=n area areound the weld to red hot, which slowly cools.

I don't know the temper of the legs, but any present temper is likely 
reduced.    I would neither heat the legs to a temper reducing dull red, 
or hotter, nor would I allow holes to be drilled the the legs and 
particularly no holes in galvanizing.  ROHN specifically warns against 
drilling out tight fitting bolt holes, or using the bolt to thread its 
way in. To enlarge the holes, use a long taper pin with a gradual taper. 
This will open the hole enough to allow "sliding" the bolt in and leaves 
the galvanizing in tact! You may have to drive the taper pin in from 
both directions.

As a general rule, for tower legs, don't heat, don't weld, and don't drill.

73

Roger (K8RI)

>
> Warren
> W7WY
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