Exothermic Ground Rod

Besides thermite, I still enjoy Nitrogen Triiodide, and really who can resist a big old batch of flash paper? At least Picric acid has that "hazard yellow" color already baked in.

 

I always love the "Been doing it that way for years and never had a problem" or "My insurance looked at and said good job" comments. Doing it that way for years doesn't make it right or effective. Soldered or brazed connections will not withstand the voltages of lightning. One strike, maybe two ... and after that ... ZORCH!

And as far as your insurance company, now they know they don't have to pay a claim and can simply deny you. Of course they said "good job" ... for them. Any work performed not to NEC anywhere nationwide (local codes do not matter to underwriters, NEC does) means they have the justification to deny a claim. Insurance companies only make money when they can deny a claim, paying a claim is a cost they do not want to incur at any time. So yeah ... good job for them.

I just built a new station at a new QTH. All ground connections are exothermic. Used the same system in the video. I have four 8' rods on the property, two for antennas, one for the AC power service, and the last for the station. All are bonded with buried #4 bare copper wire exothermically, including the 2" solid copper straps coming into the station to the 3" wide, 72" long, .25 thick copper bussbar that all the equipment is grounded to with .5" solid copper strap. Whatever hardware there is (for suppressors and such) is all 316 stainless-steel. It just doesn't make sense to do it any other way. Penny wise, dollar foolish just isn't my thang!

If my insurance company saw it, they'd say ... "Damn it!"

 

>"Exothermic welding can withstand multiple lightning strikes undamaged where often a clamped connection just blows apart."

A well-connected bond using 15% silver solder bars and an oxy-acetylene torch can achieve results identical to Cadwelding. The reason it's not specified in NEC nor local codes is that it's susceptible to too much variability in the connection. Like welding, achieving consistent results with soldering is as much of an art as it is science. The objective is to remove as much art as possible to achieve a consistent result. Cadwelding mostly meets that objective when the user follows the manufacturer's instructions.

I use both methods. There are some connections that are more conducive to silver-soldering. For example, if I need to joint two #2 solid copper wires, I place two bronze split-bolt connectors on the wires. I could stop there and meet code. But, I also silver-solder the joint in between the two split-bolts. It can be buried for eternity without future inspection, and there's no need to fear that the split-bolts have loosened or blown apart over time.

Paul, W9AC

 

I feel as though I need to clarify here. I am using a Silver and Copper alloy brazing rod - not Lead free Plumbing solder. I am connecting a #4 solid Copper wire to a Copper clad ground rod. Except for the small amount of Silver (15%) in the alloy it is a connection from Copper to Copper with Copper.

If a lighting bolt is able to 'ZORCH' that connection then the ground wire is also going to be ZORCHED along with all the mechanical connectors (split bolts) too.

I am certainly no expert in this field. But, based on experience and education, my belief system just has a hard time accepting that a mechanical connection is superior to a molecular bond.

Dan KI4AX

 

Why bother to do that when cadweld one shots are about $5 each and are much quicker? I used them for my grounding system and never looked back easiest method to bond copper together.

 

Great.....Now where are the marshmallows?

 

The chemical looks to me like Copper Thermite, which is used for Railroad Rail welding and Igniting Solid Very Large Rocket Motors

 

Yes.

 

HEY TNX FOR SHARING THIS , BUT RATHER THAN SPENDING EXTRA BUCKS ON WATEVER FANCY ETHO PRODUCTS , WILL USE EXISTING MATERIALS ON OUR HUMBLE HOMESTEAD - PROPANE BOTTLE TORCH AND SOLDER , IF GUD ENOUGH FOR INSURANCE , FB !!! (FINE BUSINESS )
WHAT HELPED ME WAS CLAMP WILL GET BLOWN APART , WILL GETTER DONE THIS WEEK .
AJ "HAMHILLBILLY " ,

 

When I was a practicing PE the NEC allowed soldered connections for everything but ground connections.

 

Hello, the Cadweld method is a simple, cheap, fast way to make ground connections that will pretty much last forever, with no fear of blowing apart or melting during a lightning "event". The temps reached can easily reflow expensive silver solder, arc the connection, and blow it out.
It's best to not advocate for methods that are unreliable and could be prone to causing damage in an "event".
Soldering ground connections will not work just at the moment when you need them the most.
Guy,
KC2PMM

 

I am a Quality Assurance evaluator for the DOD (DISA). We check grounding system and lightning protection subsystems (LPS). MIL-STD 188-124B requires grounding systems to use 10-foot 3/4" copper-clad steel spaced no further than 20 feet apart. The rods are to be interconnected using 1/0 AWG bare copper cable buried at least 18" deep 2-6 feet outside the drip line of the structure. The cable is to be brazed or welded (includs exothermic bonds). The LPS is connected to the grounding system. Soldering is not recommended for theses systems as a lightning strike will also cause high heat and the solder joint (including silver solder) may fail. I don't know if I'd trust an insurance person's evaluation... I'm sure they're not experts in the field. It's your equipment you are trying to protect. BTW, when we test a ground system we are looking for a reading below 10 ohms. The IEEE requires 5 ohms or less except in the case where a telephone switch is housed... that is 2 ohms or less. We also test using the fall-of-potential method. Any other method is not as accurate... especially a clamp on ohmmeter.

 

How long ago was that? The NEC does and has allowed soldered connections, BUT the solder can't be the means of mechanical connection. An example would be wires twisted together for the mechanical connection, and solder over that.

From a 1990 NEC "Soldered splices shall first be so spliced or joined as to be mechanically and electrically secure without solder and then soldered"

For connection to electrodes: "The grounding conductor shall be connected to the grounding fitting by exothermic welding, listed lugs, listed pressure connectors, listed clamps or other listed means. Connections depending on solder shall not be used."

28 years is as far back as my NEC book collection goes, but I will bet that the above has been in the NEC for many decades. I would love to be proved wrong with an excerpt from an older version of the NEC.

 

My PE's drawings specified bare 2/0 stranded wire.
I rented a crimp tool to make three connections:

Terminal hardware and brackets are stainless steel.

 

That is not exothermic bonding. From Wiki:

"Exothermic welding, also known as exothermic bonding, thermite welding (TW),[1] and thermit welding,[1] is a welding process that employs molten metal to permanently join the conductors. The process employs an exothermic reaction of a thermite composition to heat the metal, and requires no external source of heat or current."