Welding Tips and Tricks

So I have TIG welding for about a year or so now, but just sporadically as a hobbyist. I've used my first pack of 10 tungstens about halfway as a beginning with regrinding frequently based on contaminating (dipping) the tip.

I have a Lincoln Electric PTA-17v air cooled torch
Use 1/16th 2% Thoriated tungstens
Half my work was been in the 50-80 amp range
Recently my other half of time has been in the 120 amp range
I use a gas lens with the original collet

So... my questions is... when should I replace the collet and/or collet body? I don't know of any specific problems right now other than the fact that the color of the brass collet has changed some, but I'd prefer to avoid any potential problems simply because I didn't know when to change out a relatively cheap consumable.

Thanks,

Bill

When it shows signs of physical wear or won't hold the tungsten or if you've got a gas lense that's been damaged. Color doesn't really mean much but it can be an indication of a bad connection that's causing excessive heat inside the torch head.