In a message dated 96-03-26 10:36:12 EST, you write:
> but I really recommend that you NOT weld rebar. In addition to the
>April 96 QST Technical Correspondence (p. 79) I think it may weaken the
rebar if you >don't know what you are doing. If you buy the rebar ties of
the right length (the wires >with loops on both ends) and have the tieing
tool (only a few bucks) you can meet the >specs and save money as well as
time over the welding process.
Hiya, John --
I agree and, as you pointed out, industry standards are generally for
tieing the rebar together. The only exception that I've run across is when
you're using the concrete for an Ufer ground for your tower. As you know,
this is when you use the concrete (conductive) and the rebar together as a
ground point for your tower. This techinique is really usefull when you
don't have enough room for a regular perimeter ground system. In the case of
a Ufer ground, I think the prefered method is to braze the rebar together.
You want the rebar bonded because if you don't and you take a lightning hit,
arcing will occur in the concrete block and possibly crack the concrete.
This is what has caused people to think that a lightning strike will damage
a tower base; it is really the arcing that does it. If the rebar is bonded
and other grounding techniques are used, no damage will occur.
73, Steve K7LXC