[TowerTalk] What Welder Makes Good Exothermic Bonds?

[EUGENE SMAR]

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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