- 2% thoriated (red) for DCEN steels, grinding dust is radioactive, but longest useable life
- 2% ceriated (orange) for DCEN steels and AC welding on inverter units, not radioative.
- 1-1.5-2% lanthanated (black, gold, blue) for DCEN steels. not radioative.
- Pure tungstens (green) for AC welding on transformer units.
- Zirconiated (brown) for AC xray **** you'll never do.
If you're using an ancient transformer rectifier based tig that weighs 500lbs. Then use pure tungsten.
Most newer inverter machines in use now a days will weld much, much better using Ceriated, Lanthanated, and a *few* will do Thoriated. You'll get increased tungsten life (higher working temp). But mainly MUCH improved arc control and concentration, as you no longer ball the tungsten. You use it tapered with a truncated tip.
I'm not the biggest fan of grinding machines. We just spent $1200 on a nice water cooled machine that takes too long to correctly grind a tip. Worse yet, everyone has come to the realization after afew uses that it takes just as much operater skill as a manual grind.t's only positive is that once an operater get's it down there is a hair less tungsten consumed in the process.
Thoriated is great because it's very cheap, very common, and has the highest operating temperature of them all. Making it the longest lived. Wear a mask if you're afraid of it, but unless you're gtaw for a living you've got nothing to worry about.
To add to that, if you're welding aluminum. Once a grinding wheel has touched steel. It no longer touches anything aluminum, especially a tungsten.
And that you're most likely to die of the wood dust/particles floating in a shop due to vastly inadiquate ventallation than you are metal / tungsten particles. Metal particles might put your eyes out, but they're not generally going to be found in your lungs. (along with wood chips)