[TowerTalk] Cadweld One-Shots
Byron Tatum
bjtatum at ev1.net
Fri Aug 6 21:18:53 EDT 2004
Hello-
I have {1} a report concerning the Cadweld "One-Shots" and a {2} question regarding attaching solid ground wire to tower legs.
1. I built a all-buried grounding "grid" for a 92' 45-G tower, consisting of 6 of 5/8" x 10' ground rods. The first 3 were 8' out from base, with a rod under each guy line. The next 3 were 24' out from base, in same guy line. No.2 solid copper wire { 3 wires} ran from tower base to innermost ground rods, and then on to outermost ground rods. A 2-wire Cadweld was used on the innermost rods, whereas a triple hole was used on the outermost rods. The outermost rods were joined together by #2 wire, with a wire running between each rod forming a triangle. The first one-shot done was a dual one on one of the innermost rods. Everything was assembled as shown in instruction sheet, however most of the molten metal blew out of the bottom of the fixture. The ground rod was clean { I used the recommended drive sleeve} and polished lightly with fine sandpaper, the one-shot fixture had the gasket on bottom and it appeared OK. So, I cleaned up the top of the rod and assembled a second one-shot.There was a slight amount of coating on the rod top which made the fit a little tighter it seemed when the second fixture was assembled, and this one did OK. From then on I placed clay around ground rod, leaving only enough of rod sticking up to slide the one-shot fixture on, bottomming on the clay.The other 2 innermost rods were done using dual one-shots OK. When I did the first triple one-shot { with clay under it} the molten metal blew out one of the wire sleeves. So, I cleaned this one back -up, assembled another triple one-shot but this time I packed clay around the entire fixture nearly to the top.This time the triple made a good weld.I went ahead and did the other 2 triple's in the same fashion, as I only had 2 of triple one-shots left.Even with packing the clay tightly around the fixture {esp. where wires entered it} I noticed some molten metal getting out.
I guess my advice would be to use the larger size wire for the fixture, sealing up the sleeve area better. Mine were the one-shots for # 1-# 2 solid, or #2-#3 concentric. As it was I had a hard time finding the # 2 solid, I felt better using this in a buried application.I could see there was a tiny amount of gap around wire where it entered one-shot. I hope I can save someone else the wasted time, money and labor I lost here.
2. I have the #2 solid wire, one up to each tower leg. What would be the best long-term method of connecting each wire to a tower leg { A bolt junction it right at base area}. With all I read about corrosion, etc. I want to have it right.
Thanks, Byron WA5THJ.
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