# Cadweld



## HackWork (Oct 2, 2009)

I pour it thru the hole after it is closed. 

The last time I did Cadweld was before that fancy electronic ignitor. I still have the flint ignitors, I like to shoot sparks at the kids.


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## Cow (Jan 16, 2008)

Thanks for the info.

Every time I see Cadwelding in the specs I can't help but wonder why Burndy taps can't be used....

We are running some conduit into a substation right now and have wrecked a few of the ground grid wires digging our conduits in, under the supervision of a power co. rep. He was adamant about cadweld repairs to the ground grid, despite the fact their existing grid is using DB split bolts. 

We are using Burndy C taps on our portion of the work on our side of the demarc. When he saw the crimps go in on our side, he relaxed his position and allowed us to use C taps on their side too, for the repairs.

Maybe it's just the simple fact that some folks aren't aware there are alternatives to cadwelding and spec it that way?


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## paulengr (Oct 8, 2017)

The bad thing about cad weld is the cost of the molds and knowing how to do it. Once you have all the stuff it’s not bad. The good thing is that if it’s in the specs you’re probably the only game in town that can do it.

They’ve improved it a lot. Now you just clamp pieces of rock wool in a somewhat “universal” mold and use an electronically ignited “K-cup”. Very little mess and much easier than the old setup.


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## CoolWill (Jan 5, 2019)

I used a piece of #24 from some cat 5 shorted to a drill battery to ignite a cadweld block when the striker didn't work.


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## telsa (May 22, 2015)

The KEY thing about Cadweld: get the mold DRY before making any attempt.

This can take a lot of time.


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## HackWork (Oct 2, 2009)

telsa said:


> The KEY thing about Cadweld: get the mold DRY before making any attempt.
> 
> This can take a lot of time.


Blow torch before the first weld takes care of that.


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## Southeast Power (Jan 18, 2009)

We had to buy:
the mold
10 K cups
the electric igniter

all for one piece of 4/0 or attached to a column.


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## VELOCI3 (Aug 15, 2019)

Southeast Power said:


> We had to buy:
> 
> the mold
> 
> ...




You could’ve bought the same cadweld setup on eBay and get the shots from the electric supply house for less than 100$


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## VELOCI3 (Aug 15, 2019)

paulengr said:


> The bad thing about cad weld is the cost of the molds and knowing how to do it. Once you have all the stuff it’s not bad. The good thing is that if it’s in the specs you’re probably the only game in town that can do it.
> 
> They’ve improved it a lot. Now you just clamp pieces of rock wool in a somewhat “universal” mold and use an electronically ignited “K-cup”. Very little mess and much easier than the old setup.




I bought 115 shots because I was doing 4 different molds. They required 150, 115 and 65. I just added or subtracted from the amount to get the shot size. The K cups can’t do that. You have to have all the correct sizes depending upon the mold. 


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## VELOCI3 (Aug 15, 2019)

Cow said:


> Thanks for the info.
> 
> Every time I see Cadwelding in the specs I can't help but wonder why Burndy taps can't be used....
> 
> ...




Never seen direct bury crimps only weld. Where I’m doing it now is hard drawn 2/0 solid copper. Stiff like rebar. Excavator broke the ring so I was able to add the missing section by parallel welding the cable ends and running weld to the tops of the new ground bars. 


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## drsparky (Nov 13, 2008)

We have been using Harger Ultra Shot and Uni Shot. Cadweld makes similar Cadweld plus and One Shot. Disposable single use molds and no powder and less mess.


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## drsparky (Nov 13, 2008)

Harger








Cadweld


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## Southeast Power (Jan 18, 2009)

VELOCI3 said:


> You could’ve bought the same cadweld setup on eBay and get the shots from the electric supply house for less than 100$
> 
> 
> Sent from my iPhone using Tapatalk


I bought the igniter and had to buy a minimum of 10 of the k cups, we have a plastic tote full of molds and always feel lucky if we have something that will work.
I think it would save me a whole lot of grief if all of it disappeared and we just bought what we need when we need it.


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## joe-nwt (Mar 28, 2019)

telsa said:


> The KEY thing about Cadweld: get the mold DRY before making any attempt.
> 
> This can take a lot of time.


Also critical the previously buried cable be dried as well. Blow torch takes care of that too.


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## paulengr (Oct 8, 2017)

joe-nwt said:


> Also critical the previously buried cable be dried as well. Blow torch takes care of that too.



Agreed on wire. The mold is easy. Just dry fire one shot. Then it’s dry and heated.


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## joe-nwt (Mar 28, 2019)

While we're on the subject, with the 2 piece clamp together molds, I like to put a blob of duct seal around the protruding cable. I find this helps that prevent that eventual leak that shortens the life of the mold. Once a leak starts it's there forever as it seems to etch its way out of the mold. This trick is particularly useful if you encounter old 7-strand ground wire that doesn't quite fit the hole in the mold.


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## VELOCI3 (Aug 15, 2019)

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## VELOCI3 (Aug 15, 2019)

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## VELOCI3 (Aug 15, 2019)

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## VELOCI3 (Aug 15, 2019)

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## drsparky (Nov 13, 2008)

VELOCI3 said:


> Sent from my iPhone using Tapatalk


Is that insulated wire?


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## VELOCI3 (Aug 15, 2019)

drsparky said:


> Is that insulated wire?




Yeah. Grounding triad with 3 10’x3/4 copper clad rods. 


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## joe-nwt (Mar 28, 2019)

Why wouldn't you use bare?


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## VELOCI3 (Aug 15, 2019)

joe-nwt said:


> Why wouldn't you use bare?




The DWGs didn’t spec bare. I had the #2 in stock. The ground ring that I had to repair was bare 2/0 solid. I couldn’t find the 75’ I needed to repair it (excavator dug it up) so I used 2/0 bare copper. 




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## VELOCI3 (Aug 15, 2019)

joe-nwt said:


> While we're on the subject, with the 2 piece clamp together molds, I like to put a blob of duct seal around the protruding cable. I find this helps that prevent that eventual leak that shortens the life of the mold. Once a leak starts it's there forever as it seems to etch its way out of the mold. This trick is particularly useful if you encounter old 7-strand ground wire that doesn't quite fit the hole in the mold.




If the sides are getting worn out wouldn’t the inside area be wearing out too? 


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## joe-nwt (Mar 28, 2019)

The sides seem to wear out faster. The molds are relatively soft, I think every time you clamp a wire or adjust the position of the mold once it is clamped onto the wire, a small bit of abrasion takes place. Once a leak happens, it seems to accelerate the wear many times over. I dunno, I even do it on new molds. Seems like good prevention for a few ¢ worth of duct-seal.


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## Southeast Power (Jan 18, 2009)

Battery powered igniter. Fire in the hole boys.


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## Mobius87 (May 20, 2019)

Southeast Power said:


> Battery powered igniter. Fire in the hole boys.
> 
> https://youtu.be/u3wMKYsd588


I think you missed your calling as a cameraman.


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## paulengr (Oct 8, 2017)

joe-nwt said:


> The sides seem to wear out faster. The molds are relatively soft, I think every time you clamp a wire or adjust the position of the mold once it is clamped onto the wire, a small bit of abrasion takes place. Once a leak happens, it seems to accelerate the wear many times over. I dunno, I even do it on new molds. Seems like good prevention for a few ¢ worth of duct-seal.



It’s actually the moisture that does it. Once it is up to temperature you will have fewer problems. Heating it up with a torch is not optional.


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## joe-nwt (Mar 28, 2019)

paulengr said:


> It’s actually the moisture that does it. Once it is up to temperature you will have fewer problems. Heating it up with a torch is not optional.


It is. You have to keep the torch on it for a while. You can actually take what appears to be a dry, cold mold, start heating it with the torch and you can see the moisture start to come out of the mold where you first apply the torch. I then chase the moisture to the far end of the mold and viola, dry mold. 

No splattering on the first weld which is the indication of moisture.


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