Tungsten sharpening

[deereman75]

I finally have everything I need to start tig welding. I have my argon hooked up, and yesterday I got a pack of 1/16 inch thorinated tungsten. Anyways, I am wondering how I should sharpen them.
I don't have a bench grinder that can be dedicated to tungsten, but I do have a kalamazoo 1x42 belt grinder for knife making. I am wondering if it would work alright to put a fine (320 grit) belt on it, and keep that belt for tungsten?
I have also heard of sharpening tungsten with a cutting torch? I assume that is more of a last ditch field method?
Any advice for angles to sharpen it at, or any other tips for starting scratch start?

 

[Gary Fowler]

My first advice is don't buy anymore 1/16" tungsten, they don't carry much amperage and break off too easily. 3/32" are much better, easier to sharpen than 1/8" and can carry 150 amps easily without overheating. Your belt sander should work ok to sharpen tungsten. You don't need a dedicated stone to sharpen tungsten, it just needs to be a fine grit (320 or so) and it needs to be fairly square shoulders. I know it is not supposed to be done, but I used to sharpen mine on the sides of the wheel while pointing the tungsten slightly uphill on the stone. This pulls the tungsten away from the point and gives a good sharp point. Don't point it to a needle point as that will just break off anyway if you are using a scratch start rig.
Sharpening with a torch burns up a lot of tungsten not to mention oxygen (you sharpen it by hitting the high pressure oxygen and bringing the tungsten into the edge of the high pressure jet. The preheat flame heats it and the cutting oxygen oxidizes it away. I don't think it would work for anything smaller than 1/8" though.
One secret to how you sharpen your tungsten has to do with the angle of sharpening. A rather blunt angle (say 45 degrees from vertical will give you a shallower penetration while a long angle 60 degrees will give more penetration. This is mostly in relation to root pass on open butt. The blunt angle makes a shallow flat bead where as the long angle will make the bead "hump up".

 

[lloyd430]

WEAR a very good dusk mask when grinding carbide- the stuff if really nasty in your lungs. If inhaled it weighs too much to be exhaled and gets stuck in you! The other thing to do as well in take a cheep right angle grinder and put a diamond or CBN blade on it and it will last forever and won't heat the stick up as much as a stone wheel. Have fun!

 

[Shield Arc]

Zap over on Welding Web posted how he uses a drill motor to sharpen tungsten. For years I did just like Gary, and used the side of the wheel. But after seeing how Zap does it, I started doing it that way.
Someone posted this chart on different ways to sharpen for penetration, I guess I've been doing it wrong all these years.:confused3:

 

[deereman75]

Okay, thanks guys. I got the 1/16 tungsten because (for now) I can't see tig welding over 100 amps. I would mainly use it for sheet metal. When I start doing some heavier welding, I will get some bigger tungsten.
I am planning on doing my first tig welds today. Wish me luck..... LOL
Anyways advice on cup size and gas flow? I have #4,#6, and #9. Also, should I go with short back cap, or long? I have a pair of those things goatskin tig gloves, and some cheap copper coated filler rod. I really know next to nothing about tig..... LOL

 

[BowlBuilder]

The reason you don't want to sharpen it sideways is the small grooves left from grinding will cause the arc to jump off the side of the tungsten and not travel down to the point of the tungsten. By grinding it inline, your electricity will follow the grooves down to the end of the tungsten and give you a very nice weld puddle without arcing off to the side.

 

[BowlBuilder]

BTW, I've never used 1/16" tungsten on anything thicker than around 22 gauge sheet metal, Mr.Fowler is correct that 3/32" should cover about anything you will need to weld. Otherwise I would switch over to a mig welder.

 

[npalen]

Okay, thanks guys. I got the 1/16 tungsten because (for now) I can't see tig welding over 100 amps. I would mainly use it for sheet metal. When I start doing some heavier welding, I will get some bigger tungsten.
I am planning on doing my first tig welds today. Wish me luck..... LOL
Anyways advice on cup size and gas flow? I have #4,#6, and #9. Also, should I go with short back cap, or long? I have a pair of those things goatskin tig gloves, and some cheap copper coated filler rod. I really know next to nothing about tig..... LOL

Let us know how you get along. I'm thinking about investing in an Everlast or Longevity multi-purpose to see if I can't learn tig. All I have now is AC stick buzzbox.

 

[Shield Arc]

For now I would go with the #9 cup. Latter when you get into walking the cup, especially on V groove joints you'll want to play with different size cups to see which size works best for the bevel, and gap. I like to grind a small bevel on my cups so they slide better.
I run anywhere from 15 to 20-CFH

 

[DaveOmak]

deereman, morning.... If you sharpen thoriated tungsten, thorium is a radioactive element..... I use the drill motor, sanding belt method.... 60 deg or so works for me...

http://www.aws.org/technical/facts/FACT-27.pdf

Thoriated tungsten electrodes contain
thorium, a radioactive material that can
pose health and environmental risks at
elevated exposure levels. Thorium is a
low-level radioactive material that primarily
emits alpha particles as well as some beta
and gamma radiation. These electrodes
are normally sharpened by grinding as part
of the standard procedure while preparing
to perform gas tungsten arc welding
(GTAW). Dust particles from this grinding
process can cause internal radiation
exposure if the dust is accidentally
ingested or inhaled, so caution is
necessary. Concern regarding radiation
exposure to the external body from these
electrodes is minimal.