Hi all,
I have shot ALLOT of Cadwelds while I was working for Norfolk Southern
Railway and will add
my .02 worth.....
Cadwelds/Oneshots are great but just make absolutely sure the mold is
fully
down on
the rod till the molds metal inserts touch the top of the ground rod. Then
insert the ground wire
""OF THE CORRECT SIZE"" for the shot you are using until the tips of the
wires are touching
inside of the mold. I emphasize ""OF THE CORRECT SIZE"" since using a wire
of smaller diameter
than the inserts/mold is made for will most times result in the molten metal
flowing out through
the gaps. It goes without saying to plug any unused wire holes in the mold
with short stubs of ground
wire.
I have had success using Oneshots with the wrong sized diameter wire
hole
(boss ordered the
wrong shot:-) (#6 shots and #8 wire) by cutting 4-8 small pieces of the
ground wire and pouring
them into the mold BEFORE inserting the powder cup.
This just adds some extra material that will melt and can run out during
firing.
The one thing I will stress heavily is....
Make sure there is no strain tending to pull the wire from the hole before
firing.
If there is any tension pulling the wire from the mold, when you fire it,
there
is a very good chance that the ground wire will pop out when it melts and
there goes
the shot. When we first started using them, we figured this out pretty
quick.
I would guess I have shot 500+ of these critters over the years and
there
really isn't anything better on the market.
They even make a reusable magnetic mold to shoot to flat surfaces such as
steel building
walls or tower structures. That way you have nothing clamped anywhere.
I almost forgot. If the wires are bent slightly when trying to insert into
the mold,
DON'T try to bend the wires while inside the mold inserts to get them to
touch in the
center of the mold. Doing so will most likely crack/break the ceramic mold
in the
process.
On a side note, we also used a similar mold to electrically BOND sections of
bolted
rail together at railroad crossings to provide the crossing equipment a
constant
unchanging signal up and down the rail. If we were called out on a crossing
that
was activating with no train on the circuit, most times it would be a broken
Cadweld bond of some type. They also use Cadwelds in mines to provide
voltage into
the mines via the tracks for lighting and such.
The last part is not really on topic, but came to mind and thought I would
share. :-)
73's
RoD
KD0XX
A good friend will come and bail you out of jail,
A TRUE friend will be sitting next to you saying.....
"DAMN THAT WAS FUN"
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com]On Behalf Of Ron Todd
> Sent: Monday, June 18, 2007 7:40 AM
> To: towertalk@contesting.com
> Subject: [TowerTalk] Fw: Cadwelding and grounding nightmare
>
>
> Pat thanks for great URLs, all worked but the last one.
> http://www.generalcable.co.nz/.../cadweld.HTM
>
> Ron
>
>
> ----- Original Message -----
> From: "Pat Barthelow" <aa6eg@hotmail.com>
> To: <K8RI-on-TowerTalk@tm.net>; <ersmar@verizon.net>;
> <RadioIR@charter.net>;
> <towertalk@contesting.com>
> Sent: Monday, June 18, 2007 12:33 AM
> Subject: Re: [TowerTalk] Cadwelding and grounding nightmare
>
>
> >
> > Folks:
> >
> > For whatever they are worth, here are some pictures of a cell
> site ground
> > system under construction near N6IJ.
> > There may be clues to cadweld tecniques within the close up
> images of the
> > Cadwelded ground rods to the ring conductor in the trench.
> > See:
> > http://groups.msn.com/hamtech/shoebox.msnw?albumlist=2
> >
> > Also, I found some other useful Cadweld info:
> > http://www.k2ut.org/cadweld.htm
> > http://www.rogerhalstead.com/ham_files/ground.htm
> > http://www.generalcable.co.nz/.../cadweld.HTM
> >
> > Sincerely, Pat Barthelow aa6eg@hotmail.com
> > http://www.jamesburgdish.org
> > Jamesburg Earth Station Moon Bounce Team
> > http://www.cq-vhf.com
> >
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
> >
>
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