Welding Tips and Tricks

Hello everyone. I'm writing an article on the helium shortage and how it's impacting various industries, including welding. One article indicates that customized waveforms could serve as an alternative to helium. I don't know what a waveform or wavefront is but would like to explain it in my article. There is no straightforward explanation on the web. Could you please explain what it is? Thank you.

Welcome.

What helium shortage?

This is a myth spread by people who want to raise their rates.

Helium is a by-product of natural gas production, which is at an all-time high. There is no shortage. I use, mis-use, abuse, and waste more than most will encounter in a lifetime.

Steve S

Thank you for letting me know. I'll be sure to include this information in the article. Could you please explain what a waveform is?

Just add welding to your "waveform" search and you should get any number of hits from all the major welding machine manufactures on their different waveforms and how they affect heat input in metals. Thus eliminating or limiting the need for Helium while welding Aluminum.

Len

P.S. If you go to your neighbors for dinner, you bring something for the table. Please use our introduction page to tell us a little about yourself and feel free to contribute where you can. Read through some of the post here on Aluminum welding and you'll likely take away some new found knowledge on your subject at hand.

Those of us who have ever seen an oscilloscope depicting sine wave AC current, a horizontal line in the center of the screen is zero. Time is typically left to right. In typical alternating current, power rises from zero peaking at 1/240 of a second, from there it falls gradually to zero at 1/120 second. It immediately reverses direction shown as a gradual curve below the zero line greatest at 3/240 second, when it begins to rise back to the line at 1/60 second. This sine wave form is a nice round s curve laid horizontal on the line.

Welding requires an arc of flowing electrons to leap from one metal object to another. The gas this arc jumps is made up of gases not very electrically conductive. Ionizing the gas molecules renders them more conductive. In the case of sine wave AC current the flow of current falls to zero each 1/120 of a second, ( this describing 60 cycle AC power). A new arc with ionization must be established each half cycle.

Older transformer welders typically produced sine wave AC power at the frequency of supply power. To avoid the erratic arc characteristics with AC TIG welders, a second overrunning high frequency power source was added to the arc. This helped to some degree to maintain ionization of gas, maintaining the imbalance of electrons and protons. AC power is needed to clean fast growing oxides on the surface of aluminum, and magnesium.

Newer technology has developed welding power sources that change frequency, and provide instant reversing of direction of electron flow. With this waveform ionization is not lost. Current reverses direction instantaneously.

Helium atoms are easily ionized. The atom is open with electron easily knocked out of orbit. It is a very effective shielding gas. It is effective at conducting heat with an AC arc.

Anyone who has ever used helium as shielding gas will assure you no wave form will replace helium. Its effect on the ability of undersized welders to weld thick aluminum is amazing.

There are other wave forms for other benefits. I haven't room here to get into them.

abh84 wrote:Hello everyone. I'm writing an article on the helium shortage and how it's impacting various industries, including welding. One article indicates that customized waveforms could serve as an alternative to helium. I don't know what a waveform or wavefront is but would like to explain it in my article. There is no straightforward explanation on the web. Could you please explain what it is? Thank you.

Always wondered why some articles I read with welding references appear to make no sense - now I know.

Articles get written by using Internet "research" and then people read them thinking the author actually knows something.

Then these articles get tossed around welding forums by folks who believe it - then guys who actually know what it should say try to explain it correctly to the poor guys who were duped by an under informed author.

Stick with what you know about, which doesn't appear to be helium or welding.

quote="Bill Beauregard"]Those of us who have ever seen an oscilloscope depicting sine wave AC current, a horizontal line in the center of the screen is zero. Time is typically left to right. In typical alternating current, power rises from zero peaking at 1/240 of a second, from there it falls gradually to zero at 1/120 second. It immediately reverses direction shown as a gradual curve below the zero line greatest at 3/240 second, when it begins to rise back to the line at 1/60 second. This sine wave form is a nice round s curve laid horizontal on the line.

Welding requires an arc of flowing electrons to leap from one metal object to another. The gas this arc jumps is made up of gases not very electrically conductive. Ionizing the gas molecules renders them more conductive. In the case of sine wave AC current the flow of current falls to zero each 1/120 of a second, ( this describing 60 cycle AC power). A new arc with ionization must be established each half cycle.

Older transformer welders typically produced sine wave AC power at the frequency of supply power. To avoid the erratic arc characteristics with AC TIG welders, a second overrunning high frequency power source was added to the arc. This helped to some degree to maintain ionization of gas, maintaining the imbalance of electrons and protons. AC power is needed to clean fast growing oxides on the surface of aluminum, and magnesium.

Newer technology has developed welding power sources that change frequency, and provide instant reversing of direction of electron flow. With this waveform ionization is not lost. Current reverses direction instantaneously.

Helium atoms are easily ionized. The atom is open with electron easily knocked out of orbit. It is a very effective shielding gas. It is effective at conducting heat with an AC arc.

Anyone who has ever used helium as shielding gas will assure you no wave form will replace helium. Its effect on the ability of undersized welders to weld thick aluminum is amazing.

There are other wave forms for other benefits. I haven't room here to get into them.[/quote]

Thank you! This explanation is very helpful.