Exothermic Ground Rod

Cadwelding can be fun and exciting especially if the crucible fails! When I was in the field with DTE Energy we did hundreds of these on a typical substation ground mat. They are the only acceptable connection under ground for Substation Grounding systems. Clamps are used above ground but are very beefy. They have to stand up to mother natures ground faults (lightning) and man made ones. I used to check the connections with a Ground Megger and a DLRO (Digital Low Range Ohmmeter). Micro ohms are measured for connections and ground ohms of the entire mat is measured for ground conduction. The company usually bought swampy ground to save on grounding. N8SA DTE Energy retired.

 

FWIW, CadWeld™ is to exothermic welding, as Rollerblades™ are to inline skating. The former is a brand name (one of several), while the latter is the generic name.

Erico (owner of the CadWeld™ brandname, link) has a presence on YouTube: http://www.youtube.com/user/ERICOInternational

Harger (link) is another player in exothermic welding. They also have a YouTube presence: http://www.youtube.com/user/HargerLightning

Burndy (link) also produces exothermic weld products under the brandname thermOweld (link). They also have a YouTube presence:http://www.youtube.com/user/thermOweld/feed

 

Yeah ... those statements do need citations. These were not insurance firms, they were associations representing underwriters as-well-as government regulatory agencies, with support by inventors/engineers in New England. So these were not insurance companies, per-se. Additionally, it was not singularly standardizing sprinklers, but also Electrical standards.

This is the problem with Wikipedia, statements are made that are most times inaccurate or biased without any supporting citation.

Citation:

https://www.nfpa.org/About-NFPA/NFPA-overview/History-of-NFPA​

 

I want an equally dramatic and "energetic" way to remove a ground rod from the yard.

 

This, gentlemen, is how it is done.

 

A grenade? C4? Primacord?

 

More than qualifies. In fact if you do utility work for the Power, Telephone, Cellular, or Gas company Exothermic welding is the only approved method, no mechanical connectors allowed. Exothermic connections never fail, all mechanical connectors fail

 

All good suggestions. Unfortunately the neighbors (not to mention the @TF) would probably object.

 

It won't be as firey, but you could probably use a larger water drill pipe to go around the old ground rod and loosen it. (Hmm. going to have to try that)

 

Make your own thermite with manganese filings and aluminum powder.

 

You still need a crucible. Just buy the thermite w/ the crucible.

 

I worked for ERICO back in the day when this system was developed. I built the first prototypes of the electric igniter box and I spent weeks in the lab tweaking that little strip it attaches to. My buddy Glenn designed the clip that connects the wires to the igniter strip. I had the whole system connected to an oscilloscope to measure the energy in the discharge of the igniter.

I set off several hundred of these things during the reliability testing. Even set part of the lab on fire in the process. I had about 10 graphite crucibles set up and ready to go on one end of the bench when one spark made it from where I was testing to where I had the other 9 ready to test. All you can do is get out of the way. I had molten copper running off the bench and spalling holes in the new concrete floor. It made quite a mess.

I was demonstrating the ignition system at an engineering meeting. At the time it was just a black project box with an on/off switch and a charge and discharge button. I didn't have a fancy clip for the igniter connection so I was using an alligator clip with one wire from the igniter box on each side. I was going to show the blast from the new igniter design but when I pushed the button I rapidly realized that I was touching both wire with my thumb and finger.

At the time I was using 440Vdc and a pretty good set of capacitors. I couldn't let go the clip and I couldn't let go of the button until the capacitors drained. It was the most laughter ever at an engineering meeting. Elbow and hand hurt for a week.

Lots of great memories playing with thermite.

 

Can I have that 6:09 of my life back, please?

 

Thanks for the inside story. I always imagine that these stories exist for everything ever produced!

 

I’ll bet they do! I recall a demonstration of micro wave cooking being done by GE without the benefit of a shielded enclosure! It was during a science demonstration in grammar school. It was long before micro wave ovens were available. I also remember the shoe store flouroscopy machines. They were not around very long!