Tungsten electrode preparation

[welder123]

For the GTAW welding process of an open butt weld on 2 1/4% Cr piping would it be better to have your tungsten electrode sharpened to a sharp point or sharpened with the sharp point flattened at the tip?

 

[deanc]

I have always preferred the sharp tip,esp.for x-ray work.
"Chem-Sharp"works really well. If you grind be careful of your grinding direction. With a fine sharp tip you also must be more careful with the amps to avoid melt off and tungsten inclusions.

 

[fleamaster]

In making a butt weld on 0.040 Alu tubing is pulse welding a good technique too use?

 

[mcprofusion]

Elecrtodes used for DCEN welding are to be ground to a sharp point. The general rule is the taper should be 2 1/2 times the diameter of the electrode.

Although a sharp point on the tip promotes easy arc starting, it is not recommended because it will melt away and form a ball on the end.

Sharpen it as you always have, then slightly blunt the tip. The flat tip angle will maintain its shape within the current range recommended.


(

http://www.mcprofusion.com)

 

[jr32]

It would depend on the thickness of the sheet / plate you are welding . For higher currents you should flatten the tip slightly to prevent melt off .

 

[corvin]

Rule of thumb: Flat diameter = amperage/4000 (for example: 80A/4000=0.020&quot
Different angles produce different arc shapes and offer different weld penetration capabilities. In general, blunter electrodes that have a larger included angle:
· Last longer
· Have better weld penetration
· Have a narrower arc shape
· Can handle more amperage without eroding.

Sharper electrodes with a smaller included angle:
· Offer less arc wander
· Have a wider arc
· Have a more consistent arc

http://weldlogic.com/diamondground/howto.html