[TowerTalk] What Welder Makes Good Exothermic Bonds?

Sat Jul 3 21:21:49 EDT 2004

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 at rogerhalstead.com>
> To: <kd4e at verizon.net>; <towertalk at 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.
> >
> > _______________________________________________
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> > http://lists.contesting.com/mailman/listinfo/towertalk
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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.
>
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