The "rare earth" are the elements added to pure tungsten in place of thorium oxide.
Thorium oxide produces alpha particles, which do not promote good health.
The rare earths, as mentioned by Henry, replace the thorium oxide so no alpha particles are emitted, thus eliminating the health hazards associated with them.
You can use the rare earth tungstens anyplace you would normally use EWTh-1 or EWTh-2, i.e., typically with DCEN.
Best regards - Al
Jeremy
The "Rare Earth" electrodes you are looking at are most likely a propriatary mix of Lanthanum, Cerium, Zirconium or possibly a combination of the three.
They are referred to by AWS as "EWG" . This is the classification for tungsten electrodes that do not have a specific recognized doping percentage as of yet, or because the maker refuses to divulge their recipie.
The price looks good. But I wouldn't buy a large lot without checking them out personally first. Weldcraft is a respected brand.
They would probably be useful for both AC and DC GTAW.
"or because the maker refuses to divulge their recipie".
This kind of thinking I always found curious. What this means is that the manufacturer knows whats in it. The competition, with testing resources, knows whats in it. The only person who doesn't know whats in it is the poor bastard that is actually using the thing. And what purpose does that serve?
It works that way with so called proprietary SAW fluxes and power source technology.
Proprietary really is only proprietary to the users. Essentially, us.
Doesn't make sense to me either.
When we were running PQR's and trials for Rolls and CFM aerospace componants we were required to specify tungsten type.. So we went to the manufacturers and explained this to them, and they still would not produce the contents.. So we just went with something else.
For most manual GTAW or Plasma electrodes.. My advice is try them if you want,,,, If they work... Use em.
I thought thoria was a metal too. The problem is it is radioactive. They are even working of designs for thoria nuclear reactors to replace uranium reactors.
The rare earth electrodes are more EHS friendly. They don't have the health "concerns" and waste disposal issues that come from grinding dust from thoriated tungstens - not that there has ever been a proven case of health damage though.
Hi Jeremy! Were you trying to find out about the 2% Thorium that's added to the tungsten??? Or do you have what is known as Ceriated or Lanthanated tungsten electrodes, and you would like to find out] more about the "rare earth" metal elements which are added to the Tungsten in order to give the end user excellent arc characteristics especially on non-ferrous metal Gas Tungsten Arc Welding applications like Aluminum, some Austenitic Stainless steels, Nickel based alloys... Am I understanding you so far???
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