Towertalk
[Top] [All Lists]

Re: [TowerTalk] Cadwelding and grounding nightmare

To: "Gene Smar" <ersmar@verizon.net>, "K4SAV" <RadioIR@charter.net>,<towertalk@contesting.com>
Subject: Re: [TowerTalk] Cadwelding and grounding nightmare
From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
Date: Sun, 17 Jun 2007 23:00:07 -0400
List-post: <mailto:towertalk@contesting.com>


> Peter:
>
>     Jerry speaks the truth.  A rented trencher, like a Ditchwitch, would
> make short work of your trenching project.  I dug trenches for my 
> grounding
> wires and for my conduit system in one day with a rental.
>

When I put in a ground system like this I only put the cables about 3 to 6 
inches down so I don't need any trencher although after slitting a few 
hundred feet of sod in clay one begins to sound pretty good.


>     Jerry is also correct in suggesting that the molten shot is running 
> out
> of the holes in the (I assume) One-shot Cadweld molds.  I had the same

After reading the post I though he was talking about using the graphite mold 
and measured shots.

If he is using "one shots" it's a given the molten charge is running out, 
but the ceramic should be "banked" thouroughly in dry sand (all the way 
around and underneath.) If the charge is burning off the cable there are 
several possibilities in addition to not properly banking the mold.  Wires 
too small or an over size mold holding to large a charge. Also the wires 
must butt together tightly "on top"  and in contact with the ground rod. 
The wire should be bare and solid, but coarse stranded will work. The 
wire/cable should be of such size it just nicely fits through the metal 
thimbles in the sides of the mold.

If he's using the graphite mold then there is the possibility the charges 
may be too large.
"One shots" are far easier to use.

I would add that even the "one shots" develop enough heat and light to be 
dangerous and the proper igniter should be used. Looking directly at one 
when it's fired is as dangerous as looking directly at the sun wihout 
protection.  They are hot enough to burn through concrete. That stuff will 
go through steel plate like butter.

> problem with the first one I tried.  After I cut off the half-welded top 
> of
> the ground rod and fixed a second ceramic mold on top of it, I sealed the
> holes for the side wires and around the rod itself, underneath the mold,
> with electrician's putty (available at Home Despot, Lowe's, etc.)  I did
> twelve welds successfully thereafter.

I just thouroughly pack/bank them with sand right up flush with the top, but 
what ever method, they have to be completely contained. 
http://www.rogerhalstead.com/ham_files/ground.htm  The photos near the 
bottom show how I bank them.
I now use a NEMA box and grounding bulkhead at the entrance to the house 
instead of the fixture shown with the Polyphasers at the bottom of the page, 
but I've not had the chance to update the page.

Roger (K8RI)




>
>     Good luck with the project.
>
>
> 73 de
> Gene Smar  AD3F
>
>
> ----- Original Message ----- 
> From: "K4SAV" <RadioIR@charter.net>
> To: <towertalk@contesting.com>
> Sent: Sunday, June 17, 2007 5:35 PM
> Subject: Re: [TowerTalk] Cadwelding and grounding nightmare
>
>
>> Sounds like the molten metal is running out the holes around the wires
>> or around the ground rod if it doesn't fit tightly.  You can pack it
>> with sand to prevent this.  The trenching can be difficult if the
>> digging is done manually.  Renting a trencher can make it much simpler.
>> Putting in the ground rods is the most difficult part.  You said you
>> have already done this?  That does make the trenching a little harder,
>> avoiding the ground rods then manually digging out around them.
>>
>> Jerry
>>
>> Peter Dougherty wrote:
>>
>>>Hi all,
>>>
>>>This is a desperate plea for help from Northern NJ. I need to get a
>>>major cadweld-grounding project completed, and as events of this
>>>weekend have proven, this is not a task neither I nor my xyl are
>>>physically capable of performing. It almost ended up with me in the
>>>hospital and my wife ready to take off permanently. I am NOT joking
>>>about this, either. Yes, the fight was THAT bad. It's just the two of
>>>us here. I'm in bad condition physically and can't be outside in heat
>>>for more than an hour or so, and she can only do so much to help.
>>>
>>>I have the ground rods down and mapped out but trenching out where
>>>the wires are supposed to run and properly firing off the cadweld
>>>shots turned out to be a massive and expensive waste of time, effort
>>>and money. The last straw was the shot I fired off. Made a nice 3"
>>>flame and a couple of minutes of glowing orange, but when the smoke
>>>cleared and things cooled down out popped one of the wires from the
>>>mold as if it was never even effected.
>>>
>>>If there's anybody who is expert at this process and willing to come
>>>to northern NJ please contact me at your earliest convenience. Guys,
>>>I'm in waaaaaaaay over my head on this one. I bit off way more than I
>>>can chew and I need a pro and some folks with experience to get this
>>>done right.
>>>
>>>
>>>
>>>Thanks in advance.
>>>
>>>Peter,
>>>W2IRT
>>>
>>>_______________________________________________
>>>
>>>
>>>
>>>_______________________________________________
>>>TowerTalk mailing list
>>>TowerTalk@contesting.com
>>>http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>>
>>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk 

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>