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#91168 - 01/02/05 07:09 AM Exothermic Welding or Irreversible Connections, Comments?
Joe Tedesco Offline
Member
Registered: 10/07/00
Posts: 2749
Loc: Boston, Massachusetts USA
I am interested in hearing about your experiences concerning these two recognized code methods for splicing the GEC, etc..



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Joe Tedesco, NEC Consultant
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#91169 - 01/02/05 10:48 AM Re: Exothermic Welding or Irreversible Connections, Comments?
CharlieE Offline
Member
Registered: 04/23/04
Posts: 200
Loc: Indianapolis
The biggest downsides of Caddweld are:
  • damp molds where they have been left in a tool box or storage shed over the weekend
  • the process can not be used in rain or drizzle
  • the molds "wear out" after about 50 shots, then you have to be creative by using putty to seal against leakage or old pennies to add more copper to the mix (not listed since it changes the mix and has not been tested)
  • once in a while, if you are not careful, you will burn through instead making a good weld (operator error)

We used to use the Caddweld system for all of our grounding grids in our substations but have gone to the mechanical type because of the above downsides.

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Charlie Eldridge, Indianapolis, Utility Power Guy
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Charlie Eldridge, Indianapolis Utility Power Guy
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#91170 - 01/02/05 12:23 PM Re: Exothermic Welding or Irreversible Connections, Comments?
Physis Offline
Member
Registered: 12/28/04
Posts: 86
Loc: Burlingame, Ca. USA
Is the mold that big metal block?

50 shots, how hot does the thing get, is the steel melting?

Why aren't there replaceable inserts, are you supposed to buy a new one?

Are you an Ideal rep? (couldn't resist)
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Sam, San Francisco Bay Area
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#91171 - 01/02/05 12:52 PM Re: Exothermic Welding or Irreversible Connections, Comments?
iwire Offline
Moderator
Registered: 01/05/03
Posts: 4391
Loc: North Attleboro, MA USA
The molds well that is a the costly part.

Each mold is specific, in my cellar I have a 4/0 to 3/4" ground rod mold and a 4/0 run to a 2 AWG tap mold.

You need a mold for each different wire size or application.

The shop has a few dozen molds in stock, some have magnetic holders that hold the mold to building steel in order to cad weld a conductor to building steel.

The process is fairly simple, clean the conductors, dry the mold (and conductors if damp) with a torch, clamp the mold onto the conductors, pour in the appropriate sized 'load', close the cover, with a glove on use a striker tool to light it off.

Bright light, lots of smoke and presto you have a permanent connection if all went well.

Remove mold carefully as the weld will be red hot and the mold is also smoking hot.

I think the molds are made of graphite but I am not sure of that.
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Bob Badger
Construction & Maintenance Electrician
Massachusetts
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#91172 - 01/02/05 01:50 PM Re: Exothermic Welding or Irreversible Connections, Comments?
Physis Offline
Member
Registered: 12/28/04
Posts: 86
Loc: Burlingame, Ca. USA
Holy explative batman, those things are chemical?

I guess that explains everything but the replaceable inserts.
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Sam, San Francisco Bay Area
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#91173 - 01/02/05 02:00 PM Re: Exothermic Welding or Irreversible Connections, Comments?
resqcapt19 Offline
Member
Registered: 11/10/00
Posts: 2148
Loc: IL
Sam,
The mold is graphite and being very soft wears out from use. The openings get too larger to contain the molten copper.
Don
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Don(resqcapt19)
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#91174 - 01/02/05 03:17 PM Re: Exothermic Welding or Irreversible Connections, Comments?
CharlieE Offline
Member
Registered: 04/23/04
Posts: 200
Loc: Indianapolis
50 shots, how hot does the thing get, is the steel melting?

Sam, there is a very thin steel insert put into the bottom of the upper chamber and the reaction gets hot enough to completely melt the steel insert. The powder is copper oxide and aluminum, I believe. It is required to get a hot enough to actually make a weld. In my opinion, if done properly, the Cadweld makes a perfect connection and nothing is better.

Because of the graphite mold getting a little oversized, I have used old pennies (the newer ones are copper plated zinc) to take the place of the steel insert. As I said before, this is not an approved method.

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Charlie Eldridge, Indianapolis, Utility Power Guy
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Charlie Eldridge, Indianapolis Utility Power Guy
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#91175 - 01/02/05 06:45 PM Re: Exothermic Welding or Irreversible Connections, Comments?
Jps1006 Offline
Member
Registered: 01/22/04
Posts: 615
Loc: Northern IL
Quote:
I have used old pennies to take the place of the steel insert.


U.S. Treasury may object too. I think technically they own the penny, you just own the value it represents.

[This message has been edited by Jps1006 (edited 01-02-2005).]
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#91176 - 01/02/05 11:02 PM Re: Exothermic Welding or Irreversible Connections, Comments?
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9038
Loc: Estero,Fl,usa
I guess the T men are after me too. I use pennies for shot pin washers.
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Greg Fretwell
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#91177 - 01/03/05 08:47 AM Re: Exothermic Welding or Irreversible Connections, Comments?
Yoopersup Offline
Member
Registered: 03/04/03
Posts: 822
Loc: Michigan
Used um both cadwelds a pain in the _____
The crimp works Great just the tool is very expensive. There are now premade cadeweld charges made no pennies required that are set off electricaly no flame required.
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