Richard,
I compared the Exothermic welds and decided to use them. I HIGHLY
recommend that method over clamps. I compared the overall cost to using
clamps and it was 50-50. They are nearly the same.
The benefits to the Cad weld are FAR above the clamp method. I did
considerable research aside from the recommendations on this site and
found that it outlasts the clamp method 10 to 1, they can't oxidize, and
mechanically become one junction because of the melting of the materials
(~4600 Deg.). Clamps will last about 2-3 years and the Cad weld will
easily last 30+ years! That is no jive. I initially choked at the cost
since it was $63 dollars for the mold, $35 for the handle to hold it
(required), and $5.50 a shot to do 3/0 cable to the top of the ground
rods, but I found that the clamps to do the same connection were $17
each at an electrical distributor with contractor discount! The
exothermic method was developed to connect a wire between railroad rails
to get signaling systems in the '30's.
It is also actually faster to do the connection than clamping. After
getting the procedure down, it took me about 2-3 minutes to do a
connection. I just wire brushed the top of the ground rod, the wire was
already new from just having stripped it (a minor wire brush if not)
clamp the mold around it, pour in the weld metal and ignite it. It
takes 2 seconds tops for the reaction and about 30 seconds to let it
cool and set. Done! Trying to apply oxidization compound and getting
the clamp tightened down inside a hole while expecting to keep the cable
positioned was about a 15 minute job at best! Finally, none of the
clamps that I saw keep the cable going in a straight line. I had to
make sharp bends to enter and leave the connection. A no-no for
lightning conduction to make sharp bends!
I have no affiliation with Cad weld, but was very happy with the
results!
Regards,
Dave KG7EW
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