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Re: [TowerTalk] What Welder Makes Good Exothermic Bonds?

To: "Tower (K8RI)" <tower@rogerhalstead.com>
Subject: Re: [TowerTalk] What Welder Makes Good Exothermic Bonds?
From: Phil Camera <kb9cry@comcast.net>
Date: Fri, 16 Jul 2004 20:49:14 -0500
List-post: <mailto:towertalk@contesting.com>
Personally I pay only about $6 each for my OneShots. I have to order a case at a time (12 ea.) and order from the local industrial supply house (I use Steiner Electric) with whom the plant has an account. I'm not sure if there is any Hazmat charges for shipping to Steiner from Erico; all the units are so to speak deactivated and are not listed as pyrotechnics or explosives. Phil KB9CRY

Tower (K8RI) wrote:

Unfortunately for me the shipping would be a killer.  There is this Hazmat
thing about to contents. <:-))  Besides I have a full carton of the things
out in the shop.
I was paying about $8 plus change, but the last time the price had gone up.

Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com




TT:

Check out www.therfc.com (The RF Connection) near here in


Gaithursburg,


MD. Their prices for one-shots are a bit better than ten bux a piece.

73 de
Gene Smar  AD3F
(Not an employee, just a satisfied customer.)

----- Original Message ----- From: "Tower (K8RI)" <tower@rogerhalstead.com>
To: <kd4e@verizon.net>; <towertalk@contesting.com>
Sent: Saturday, July 03, 2004 3:53 PM
Subject: Re: [TowerTalk] What Welder Makes Good Exothermic Bonds?








If you are talking ground rods, it's by far cheaper (and easier) to


just


purchase a few "one shot" cartidges. Everything comes premeasured.


You


just


fit the form around the rod, put the ground wire in the opening(s)


provided,


pack dirt around the form, pour in the charge, put on the top, add


the


igniter charge, and touch it off with an igniter.
http://www.rogerhalstead.com/ham_files/ground.htm


It would appear that I am looking at 12-15 ground rod welds, plus


maybe


some rebar welds, that's a lot of disposable "one shots"! ;-)


I now have some where around 33. I lost track. <:-)) Purchasing them by


the


carton they are roughtly $10 each. There are 12 per carton and of


course


the price break comes at 13. IF they have to order them they are


available


only by the carton, at least around here.

Of course $200 worth of one shots is a lot less than a $900 welder, let
alone a $4000 welder.
Then, unless you are already a welder, you have to learn how to use the


darn


thing.

Then again you are *almost* guaranteed a good weld if you follow


directions


with the one shots.  They are fast and contain just the proper amount of
filler and give a joint that would take either a lot of skill or luck to
match with other forms of welding.

There is also the carbon block/form and purchasing the charge in bulk.


As


I


recall the break even point was around 12 to 15 welds. I would have


saved


money by going that route, but I didn't want to mess with the carbon


block,


or keeping that much thermite in my shop.


I will not only be using it for the house and tower-related


I would add that using a TIG welder is very much like using an


OxyAcetylene


torch, but the heat is supplied by an arc. The arc supplies the heat


and


you

I should have noted It's also more concentrated.



feed in the rod just like brazing or torch welding. As with MIG


welding


you


need a nice calm day outside.


So far I am seeing TIG welders for $900. - $4,000!  Out of my range
for sure!  Perhaps something used/refurbished?

I have yet to find any reference to copper and references to
only certain models sufficient for aluminum. Hmmm.


They may not reference it, but any TIG welder that has the heat capacity
should work on coper and aluminum. You'd probably need to use a


different


cover gas though.


There are several problems using an arc on Aluminum and copper. As I


recall


the big difference is between the voltage necessary to establish the arc


and


that required to carry the current to melt the metal. It takes a *lot*


of


heat (BTUs) to melt Copper and Aluminum copared to steel even though


steel


has a much higher melting point..That is one of the things that raises


the


price.

Also "to me" TIG welding is much more of an art than MIG, or stick


welding


and a class on welding would be a good idea.It usually takes most people
quite a few hours before they can run a good horizontal bead/weld


joining


two flat plates with any type of welding.

I still think your best bet for the ground rods is the one shot approach
followed by OxyAcetylene. Bernzomatic does make a OxyAcetylene and
OxyMapgas torch with tanks the same size as the butane tanks. I think


the


tanks run on the order of $10 to $12. One tank of Acetylene would


probably


get you through ... guessing... maybe 6 or so ground rods. I'm not sure


how


far the Oxygen would go.  They are limited to using a relatively low
pressure which means the tanks will probably not last long.

To braze the copper cable to a ground rod I'd get a good thick coat of
brasing rod melted to the top of the rod and then using lots of flux


work


up


through the copper cable, or thouroughly coat the copper with brazing


rod


and then bond the two together. That might be easier.You do have to be
careful as the melting point of coper is close to that of the brazing


rod,


but it can be done. With experience the copper could be brazed to the
ground rod with a secure and good looking joint. Unfortunately


experience


costs money and lots of time, at least for most of us   <:-))  To top it
off, mistakes can be expensive.



Guess I need to keep learning and searching


We all do. I was counting on that 290 million lottery for my new floor


mill


and lathe <:-)) Maybe I should buy tickes next time to increase my
chances... slightly?
.


You *might* find a reconditioned TIG, but the ones I've seen were all
industrial size units and still expensive. My neighbor is a rep for one


of


the local industrial suppliers which does help a bit <:-))

Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com


73, doc kd4e
_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers",


"Wireless


Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with


any


questions and ask for Sherman, W2FLA.


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_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless


Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with


any


questions and ask for Sherman, W2FLA.


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


_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless


Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.


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





_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

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



_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

_______________________________________________
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