Copper/ Bronze thermit: was: Something very odd on Ebay



I've just seen this five year thread; this is the first time I've visited his group, and Google won't let me reply to a post that old. If it's of any interest, there was, and probably still is, a process for attaching track circuit bonds to rail ends using a thermit-like process, which produced some sort of copper/bronze metal. I don't know the composition of either the mixture used, or the metal produced. This process was quite common at one time, especially on third-rail electrified lines, where very heavy bonds had to be used, as they carried not only the track circuit current, but also the traction return current, but the need for such bonds has been much reduced by the use of continuous welded rail.
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On Sun, 27 Jan 2008 11:51:56 -0800 (PST), snipped-for-privacy@mail.croydon.ac.uk wrote:

I think that you are talking abut the "thermo weld" process which uses a powdered mix of copper oxide and aluminum to make electrical joins. I believe that Mc masters Carr sell the kits. If not have a look at www.mastercomm.net/exothermic_weld.htm.
Bruce-in-Bangkok (Note:remove underscores from address for reply)
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I sold a bunch of such copper joining compounds under brand name Cadweld.
i

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On Sun, 27 Jan 2008 19:55:02 -0600, Ignoramus29173
That was also one of the trade names for the stuff. We used it mainly for making permanent joins to ground rods so that you could drive the rods and sorta forget them. the mechanical clamps tend to corrode in jungle climates.

Bruce-in-Bangkok (Note:remove underscores from address for reply)
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