[TowerTalk] Ground rod connection: Cadweld or ????

Kelly Taylor ve4xt at mts.net
Mon Apr 24 09:47:05 EDT 2006

Hi Bob,

Cadwelding, once you know some of the tricks, is dead simple.

Key things to remember are:

1. Matches or other simple flames will not ignite the material. It's
deliberately designed such so that the material is less volatile for
shipping and storage. The sparker RFC sells is designed to cast sparks
forward, as opposed to down, such as with a propane torch spark ignitor.

2. Grind/cut off mushrooming: when the thing says it fits 5/8-inch rod,
that's ALL it fits. The bits spread out by pounding the rod will prevent the
form from sliding on.

3. Secure the wires from movement: the combustion process can exert some
force on the wire, causing it to be ejected from the form. End result,
useless weld. Doesn't need to be much: a brick a foot or so away from the
form preventing the wire from moving is all it would need. The force is
enough a free wire can be cast out, but not so big as to bend the wire.

4. The risk, if there is any, is similar to lighting a barbecue. Don't put
your head over the form and you'll be fine. It's not like you're lighting
fireworks and need to retreat quickly. The ones I did had maybe 3 inches of
flame, and it took a second or two to build to that anyway.

5. Expensive? About $8, as I recall. A ground clamp is about $3, no? So for
an extra $5 you get a maintenance-free connection for life. Not a bad deal.

73, kelly

----- Original Message ----- 
From: <ersmar at comcast.net>
To: "Bob Kellow, W5LT" <W5LT at comcast.net>; <towertalk at contesting.com>
Sent: Monday, April 24, 2006 12:44 AM
Subject: Re: [TowerTalk] Ground rod connection: Cadweld or ????

> Bob:
>      I used Cadweld's One-Shots for my ground system.  These are
single-use ceramic molds and powder shots, rather than the heavy-duty clamp
and mold system of large commercial jobs.
>      I got my one-shots from The RF Connection near my home QTH (full
disclosure: Joel of RFC and I are both members of PVRC, if that means
anything.)  I believe they cost me around $8 per connection.
>      I couldn't think of an alternative that comes close to Cadwelding for
ground rod and wire connections.  If you want pricing from RFC, go to
www.therfc.com and check out grounding.
> 73 de
> Gene Smar  AD3F
>  -------------- Original message ----------------------
> From: "Bob Kellow, W5LT" <W5LT at comcast.net>
> > HI All:
> > I am putting in a ground system at my new QTH. Will have a ground ring
> > the tower with (4) ground rods, plus (2) radials plus a home run
> > but in parallel with the RF and control cables running to the tower from
> > shack (about 90 ft).
> > There will be three rods along each radial leg.
> > I know Cadweld (or equal) is the best ground wire to rod connection, but
> > what should I use as 2nd best? Cadweld seems to be rather expensive, and
> > takes some skill to implement.
> > Open to any suggestions.
> >
> > Bob, W5LT
> >
> >
> > _______________________________________________
> >
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> >
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