Today's MIG welding processes are faster, more efficient and more versatile than their alternative, stick electrode welding. The TIG process can also cut time and costs. Problem is, both MIG and TIG require more planning.

In addition to base metal type and thickness, weld joint design and welding position, welders using continuous feed wire or tungsten electrode process must consider yet another variable: shield gas.

Since no one shielding gas works well in every application, you're faced with the chore of choosing from a number of gases and gas mixtures. The wrong choice can cause poor penetration, undercutting, spatter, oxidation or an unacceptable bead profile. So, to help you avoid those problems, we're making it easier for you to make the right choice.

As you may have guessed, there are no secret recipes using exotic ingredients. Shielding gases are simply gases, or mixtures of gases, with which we're all familiar.

The difference lies within the blending process. All Silver Shield blends are precise to within ±1% throughout the cylinder. Not only can you be assured of their accuracy at the time that they are delivered, they will remain consistent throughout the use of the cylinder. You can use a Silver Shield cylinder blend down to 40 p.s.i. without seeing any inconsistencies in shield gas performance. Poorly blended cylinders can cause poor welding performance and wasted time spent continuously adjusting machines.

Gas Metal Arc Welding (GMAW) is an arc welding process that uses an arc between a continuous filler metal electrode and the weld pool. The process is used with shielding from an externally supplied gas and without the application of pressure.

At first, GMAW was considered to be a high-current density, small diameter, bare metal electrode process, using an inert gas for arc shielding. Subsequent process development included operation at low-current densities and pulse direct current, application to a broader range of materials, and the use of reactive gases (particularly CO2), and gas mixtures. This latter development has led to the formal acceptance of the term Gas Metal Arc Welding for the process because both inert and reactive gases are used.

The heat (generated by the electric arc) melts the metal of the workpiece and forms a molten pool. At the same time, the electrode wire melts and adds to the pool, which forms the weld.

Gas Tungsten Arc Welding (GTAW) is an arc welding process that uses an arc between a tungsten electrode and the weld pool. This process is also called TIG (tungsten inert gas) welding, but should be referred to as GTAW because shielding gas mixtures which are not inert can be used for certain applications.

The basic difference between Gas Metal Arc welding and Gas Tungsten Arc welding is that the electrode used in the Gas Tungsten Arc welding process does not melt. Instead, an arc struck between the non-consumable tungsten electrode and the work, produces the heat necessary to meltl the edges or surfaces of the parts to be joined. The parts fuse as the weld metal solidifies.

The TIG process is extremely versatile, and, because the process offers precise heat control, it is well suited for welding light gauge materials. Additional filler metal may be manually added into the weld puddle if needed.

General Air Service and Supply has over 20 years experience in the production and distribution of welding gas mixtures. Our advanced mixing techniques assure a thorough mixing of all components and the reproducibility of mixtures. We presently have six locations in which to service you in the Front Range area. We are ready to answer any of your questions.

General Air has also developed and fully implemented a computerized, serial number and delivery verification tracking system to help you track and control all of your cylinder usage. Our bar coding system offers some of the finest features available in the Compressed Gas Industry. Ask us how we can help you better control your cylinder usage.