Galvery - Basic Welding for Farm and Ranch: Techniques and Projects for Fixing, Repairing, and Fabricating Essential Tools and Equipment

A portable oxyacetylene welding setup can be inexpensive and versatile.

Oxyacetylene: How It Works

When combined in the correct proportions in the welding torch handle, oxygen and acetylene gases produce an approximately 5600F (3100C) flame at the torch tip. This flame melts the edges of the base metals to be joined into a common pool. Sometimes additional filler metal is added to the molten pool from a welding rod. When this common pool cools and the metal freezes solid, the joined metals are fused together and the weld is complete. The resulting weld should be a homogeneous mixture of the parent material (the parts being welded together) and the added filler material. The weld should be at least as thick as the thinnest parent material section.

Shielded metal arc welding (SMAW) machines have been used in the United States since the early days of the twentieth century. This form of welding is popular for industrial, automotive, and farm repair because its equipment is relatively inexpensive and can be made portable. More welders have learned this process than any other, and many refer to it as stick welding. Although it remains a widely used process, it is declining in popularity as wire-feed welding processes (MIG, flux-cored arc welding) continue to gain popularity and market share. Stick welding is a good go-to choice for repairing broken and worn equipment that has been exposed to oxidation, grease, oil, or dirt, due to the cleaning capabilities of the electrode flux coating (which removes contaminants from the working surfaces).

Stick Welding: How It Works

In stick welding, an electric circuit travels from the welding power supply to the electrode (the stick), the welding arc, the work, and the work connection, then back to the power supply. Temperatures within the arc exceed 6,000F (3,300C), heating and melting both the electrode and the base metal beneath it. As the welder moves the electrode away from the molten pool, the molten mixture of electrode and base metals solidifies and the weld is complete. See for more about stick welding.

Although the equipment may cost more than arc welding equipment with similar capabilities, a MIG (metal inert gas) welding setup offers higher productivity, and it is relatively easy to learn. Not having to stop a bead, change electrodes, and restart again increases metal deposition rates and reduces weld discontinuities. Because of this, its one of the most popular welding processes, and can be used for projects ranging from light duty, thin sheet metal auto body repair to fixing a tractor bucket with a piece of thick plate steel, and even for fabricating your own custom welding table.

MIG welders contain an internal wire-feed mechanism that feeds welding wire to the gun.

Wire-Feed Welding: How It Works