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[TowerTalk] Homebrew Exothermic Mold

To: towertalk <>
Subject: [TowerTalk] Homebrew Exothermic Mold
From: David Gilbert <>
Date: Sat, 21 Aug 2010 09:54:53 -0700
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I fabricated my own Cadweld-type mold for making ground rod connections 
while I was installing my tower about a year and a half ago, but I only 
recently uploaded the description and pictures to my web site.  It's an 
easy procedure and with a little thought a mold could be made for just 
about any configuration or purpose.  Here's the link in case anyone 
might be interested.

At the time I even tried to make my own weld powder (thermite).  It's 
fundamentally a combination of copper oxide and aluminum power and the 
formula was simple to figure out, but I couldn't find materials with the 
right particle size.  The stuff I found was all very fine powder and 
while the mixture reacted, it did so too quickly and the result was more 
like the old flash trays they used for taking photographs in the 
1800's.  If I could find an easy source of coarser powder I might try it 
again sometime, but in reality you can usually find regular Cadweld weld 
metal on eBay for the equivalent of one dollar per shot or less.  I 
always look for the largest containers I can (usually 200 grams) because 
they usually are the cheapest per gram.  I can typically get three shots 
out of one 200 gram cylinder.  Don't worry about running out of the 
starter powder (which appears to be just the same formula with smaller 
particle size like I played with anyway) ... 4th of July sparklers work 
fine to fire off the regular Cadweld powder.

Dave   AB7E

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