We have several large industrial corporations that we supply Plasma Arc Welding (PAW) torches and replacement parts to. One of them came to us for some help resolving inconsistent welds on a Thermal Arc® Ultima 150 Plasma Arc Welding machine with a 4A PAW torch and lead assembly. They were frustrated and had tried many different solutions from a variety of sources. I went through our basic PAW check list (which you can find in the Arc-Zone.com Welding Library– “Optimize Your Plasma Arc Welding Torch”). We did find two areas to improve, but the issue was still there. That’s when I asked “when was the last time you changed your lead set?”

“We just changed torches, we do that pretty often,” he said. “Why would we need to change the leads?”

With Plasma Arc Welding there are two important things to consider:

1. Plasma Arc Welding Torch Lifespan.
PAW torches have a life span of about three months. Now anybody that is familiar with automated TIG applications can’t understand why Plasma Arc Torches fail so often. There is no easy answer, but it is a characteristic of Plasma Physics. There are many more things going on inside that PAW torch than in a TIG torch — two power circuits, two gas distribution and flow paths, two water channels, tungsten electrode insulators etc. Bottom line is you should always have a spare Plasma Arc Welding torch on hand because when they fail they are junk. You’ll have no warning, and you’ll be down until you get it replaced.

2. The Lead Set
I call them leads because they consist of multiple hoses and cables inside a jacketed cover. And they wear out. Operators often don’t think to add the leads to their preventative maintenance schedules but they should.

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Arc-Zone’s own Joe Welder, aka Jim Watson, is on his way to Chicago for the Fabtech/AWS (American Welding Society) Trade Show.

Jim didn’t have much time before he left to write about the show, but he did shoot me an email and asked me to post it:

For the longest time the AWS (American Welding Society) staged their own stand alone welding trade show in April of each year and it rotated primarily around the cities in the midwest.

With the continued acquisition of many small specialty manufacturers, the show’s attendance diminished and lost its luster. Recently the AWS and Fabtech shows merged to combine one big metal working extravaganza!

If your like me and love to see all the good stuff this is the palce to be!
Plan on it this weekend in Chicago!

See you there!
–Jim

There’s an impressive list of exhibitors at the show, and some great welding seminars and other programs, including the 2007 PROFESSIONAL WELDERS COMPETITION where you could win $2,500.

Expect a full report and maybe even some information and pics of some great innovative products from Jim when he gets back.

The Plasma Arc Welding process is an interesting and technical process, it can be considered very basic, but that said, there are many things that can go wrong.

We get a lot of calls from customers using Plasma Arc Welding torches that have failed. So we developed a check list that we go through to determine what caused the torch failure.

Generally the PAW torch body arcs out internally, which can be caused by low quality replacement parts, inferior tungsten electrode, poor or inconsistent tungsten electrode grinding, dirty parts, gas leaks in the supply hoses, worn out power cable leads….

Most commonly, however, plasma arc welding torch failure is caused by incorrectly installed replacement parts.

That’s right, operators consistently install the ceramic electrode insulator/gas distributor in the wrong direction, or worse yet they modify it by breaking of portions of it! This is common on the Thermal Dynamics 3A series torches.

The part #9-2240 (photo) is a technical ceramic molded piece that has a series of strategically placed gas channels and distribution ports which optimize the inert gas that flows through the torch and directs it to the constricting tip which then forms a superheated column of Plasma gas. It is absolutely necessary that this piece be installed with great attention to cleanliness and that it is positioned correctly.

Note: there is a newer version of the part #9-2240, pictured below.

Pictured here (left) is the new style of the 9-2240 insulator / gas sheild.

The end pointing to the top left corner is the sleeve or collar end which is directed up to the top of the torch toward the collet / insulating cap.

Pictured here (right) is the 9-2240 insulator / gas sheild with the sleeve or collar pointing to the bottom right corner of the picture.

Here is an interesting article on a new inspection product.

Automation is becoming widespread in the welding industry, not only with respect to robotic welding but in the area of robotic vision inspection systems. Companies install robotic vision inspection systems for the same reasons they install other automated systems: to reduce costs due to poor quality welds; improve weld quality and consistency; increase productivity; and as a way to offset a lack of skilled labor. Additionally, if one automates the welding process, it makes good sense to automate the inspection process as well.
READ “New Automated Welding Inspection Systems” at Welding magazine online….blockquote>

Whether you’re doing PAW (plasma arc welding), or TIG/GTAW (gas tungsten arc) welding, there’s a lot of confusion about what kind of tungsten to use. At Arc-Zone.com we’ve put together a guide (.pdf) to the various blends of tungsten electrodes for welding.

These days most of the inverter welding machine manufacturers are recommending the Ceriated (Orange) or Lanthanated (Gold) as good performing alternatives to the 2% Thoriated (radioactive) tungsten electrodes. Arc-Zone offers a great selection of tungsten electrodes, including the Hyperformance(TM) ArcTime(TM) all purpose tungsten electrode. This is one tungsten electrode that will make you throw away all the rest. In fact, if you’re like Arc-Zone’s other customers, you’ll call us up to sing its praises.

Arc-Zone also carries the new Weldcraft Premium Tungsten Electrodes, including the “Rare Earth” blend– it was put through some rigourous tests in the Miller TIG welding Lab and came out on top.