[How-To] Grinding/sharpening tungsten: does abrasive direction matter?

[benmychree]

From the good ol' textbook:

I have always ground the tungsten to a sharp point and have never had any problem with the arc wandering. nearly all of my experience is with 300 series stainless steel.

 

[xr650rRider]

Put the tungsten in a drillmotor and spin it while your grinding, makes quick work. I've got a dedicated diamond wheel on a 6" grinder.

 

[pontiac428]

I have always ground the tungsten to a sharp point and have never had any problem with the arc wandering. nearly all of my experience is with 300 series stainless steel.

The sharp point erodes quickly to a stable point in short time anyway, so I see your point.

I used to get 300 series cheap, like $0.40 a pound, so I'd salvage commercial kitchen stuff that was in line for the claw to load it into rail cars back when places like that existed. I made everything out of stainless because I could!

If I have a piece of freshly ground tungsten that I don't like the arc on for some reason, I just switch into DCEP for a sec and zap the table with an arc until the very tippy tip melts into the tiniest of domes at the very end of the point. That makes for a nice uniform arc after switching back to DCEN and resuming work.

Edit:

I want to clarify that I'm rounding the point, not balling the tungsten. A ball has a waist line, it's fat in the middle. That bulge will disrupt the flow of electrons coming off the point in DC. By "doming" the very point of the tungsten, I'm not increasing diameter or even changing the profile of the cone, just melt-blunting the tiniest part of the tip where a burr might be after grinding.