Weld Like a Pro

Optimizing Plasma
Arc-Welding Performance

An ARC-ZONE.COM
Product Selection Guide

02-10-2022

GeneralMIG/GMAW

TIG/GTAW

Stick/SMAW

PlasmaGeneral/Multiprocess

Introduction
Plasma Arc Welding (PAW) is a welding process utilizing plasma, a gas
which has been heated to a high temperature and ionized. The plasma
becomes electrically conductive, transferring an electric arc to the workpiece through a small orifice. This ensures a high concentration of heatto a small area. The shielding gas enters the arc-zone and channels theplasma to the work piece.
Because of the advanced level of arc control and accuracy, PAW isparticularly well-suited for use in precision welding applications. The
resultant weld is extremely high-quality due to the high concentration ofheat delivered through the plasma torch and due to the use of shielding
gas which protects the molten weld puddle against oxidation.
The welding arc transfer is gentle, consistent and accurate, allowing for welding of thin sheets, finewire and miniature components.
Plasma arc welding is a precise process and the narrow columnar arc accepts fewer tolerances
than the wider arc of the GTAW process. Even the slightest adjustments, or process variations cancause problems such as premature torch failure and difficulty starting.

Premature Torch Failure
Problem
One common problem is premature torch failure. For high-production work, this can be frustrating,
not to mention expensive, if you have to stop production to replace a damaged torch. While first
instinct may be to blame the torch manufacturer, this may not be the case.
Arc-Zone.com Recommended Solution
When setting up your torch, do not modify any of the replacement parts. These are highly
engineered components and should not be tinkered with.
One of the most common causes of torch failure is o-ring damage. This can be caused by assembling
dry, un-lubricated liners into the torch, or by not replacing cracked or worn o-rings around theshield cup, torch body, backcap etc. This is an easy replacement and the first thing you shouldcheck.
Check gas pressure and flow rate. Use a high-quality flowmeter and be sure to set the pressureand flow rate to the recommended setting for your equipment and application.

Arc-Zone.com, Inc. • 1331 Specialty Dr • Vista, CA 92081 • Tel. 1.760.931.1500
Email: info@arc-zone.com

Whether you’re using OEM parts or aftermarket parts, use only high-quality replacement parts
from a verified supplier. Variations in manufacturing processes from several manufacturers cancause tolerance stack-up problems that will lead to inconsistent welding performance.
Use high-quality precision ground tungsten electrodes from a trusted pre-ground tungsten electrodesupplier like Arc-Zone.com. This will ensure that correct electrode tip geometry and ground finish
is main-tained. If you are grinding or re-grinding your tungsten in-house use a high quality
tungsten grinder and follow the manufacturers grind specifications closely.
Deep electrode setback can cause inconsistent arc starting and torch failure.
manufacturer’s settings guide for electrode setback and tip orifice size.

Follow theConfirm the transfer-arc mode is selected on the power supply.
Check the electrical integrity of the work lead cable, cable connection to the clamp and work piece.
Be sure to maintain the proper tip to work piece standoff. You can take the guess work out of thisprocess by using an arc voltage sensing control.

Difficulty Startin
Problem
Another common problem is that the torch is hard to start. In an optimal set up, the pilot arc isinitiated between the torch electrode and nozzle tip. The arc is then transferred to the weld piece,
delivering intense heat to a small area by forcing the gas and arc through a small orifice in thenozzle/tip. If the transfer is not initiated, there are several factors that need to be examined.
Arc-Zone.com Recommended Solution
Start problems are often caused by inconsistent gas flow rates. Be sure to use a high-quality gas
flowmeter. Gas flow problems may also be caused by the plasma arc nozzle/tip orifice. Make sure
you are using the right size orifice for your welding application.
A leaking o-ring or backcap can also cause problems in starting. Look for blueing on the tip of thetungsten, indicating outside air is leaking into the torch. This will also be apparent in the weld
itself, which will have a grayish tint and may fail an x-ray inspection. Additionally, verify that thepower supplies pilot board and pilot arc resistor are operating properly.

Conclusion
Although the plasma arc welding process requires precision and consistency in set up andmaintenance as well as the use of high-quality parts from companies like Arc-Zone.com, thestable, concentrated arc delivered at lower amperage results in a high-quality weld suited for biomedical, pharmaceutical, food processing, dairy, brewery, power generation, aircraft, aerospace,automotive and many other applications.

Arc-Zone.com, Inc. • 1331 Specialty Dr • Vista, CA 92081 • Tel. 1.760.931.1500
Email: info@arc-zone.com

About ARC-ZONE.com
Jim Watson
Jim is CEO and founder of Arc-Zone.com. He is a master fabricator with years of hands-on experiencein his own shop and also as a winning motorcycle racer, car builder, and chief mechanic for a
top motorsports team. He also has extensive experience in manufacturing, technical sales, andproduct development. Before launching Arc-Zone.com, he held leadership positions in some of themost respected companies in the welding industry.
Arc-Zone.com
Under Jim’s direction, Arc-Zone.com has led the industry in product innovation and online sales
and service, becoming the world’s leading supplier of high-quality, high-performance welding andmetal working tools and accessories.

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Arc-Zone.com, Inc. • 1331 Specialty Dr • Vista, CA 92081 • Tel. 1.760.931.1500
Email: info@arc-zone.com