Broken, rusty parts are common fare for classic trucks. Rust penetrates the pores of older metal, and even with glass-beading and acid dips, rust remains chemically embedded in badly oxidized metal. Of the many metal repair methods, old and scaly smaller parts respond well to oxy-acetylene welding (OAW).
Electric types of welding require clean, chemically sound base metals. For older parts restoration, "stick" (SMAW) or "flux-core" would be friendlier forms of electric welding. In each of these processes, the flux helps flush out impurities and oxides. These methods of welding require a flux-core MIG machine or the conventional "buzz box" stick welder. For thin or frail metal, either of these processes can be a challenge. Starting or striking an arc is difficult on etched and oxidized small metal parts.
Oxy-acetylene welding and cutting processes are as old as the automobile. Gas welding is effective and thorough. Its continuous heat source can control and move puddles of molten metal. By using the right filler rod, weld strength equals or exceeds that of the base metal-much like other welding methods do. Without the challenges of starting an arc or skipping across irregular surfaces, oxy-acetylene welding produces quality repairs on older parts.
To combat impurities in the metal, oxy-acetylene filler rod is often alloyed with metals and chemicals that produce a cleansing, purging, or deoxidizing effect. With experience, a gas welder can apply heat and filler material properly while flushing impurities to the surface of the molten puddle. By contrast, stick or flux-core welding fluxes often obscure a badly oxidized section of old metal, making it difficult to flush out impurities.
When metals become thin and unpredictable, oxy-acetylene welding offers a high level of heat control. By pulling back the tip's flame, the welder quickly changes the temperature within the heated area. TIG welding offers this feature, too. However, this welding requires a spotless, chemically stable base metal. Given all factors, gas welding often proves the better choice for older metal parts.
If there's a downside to oxy-acetylene welding, it's that gas can be expensive. Use of mixtures like MAPP gas can sometimes reduce gas cost. Surprisingly, the simpler way to conserve in the gas welding and cutting process is to use the correct gas pressures and torch tips. When working with smaller metal parts, thin and fragile metal, or confined weld areas, smaller tips and lower gas pressures can dramatically decrease gas consumption.
For the three projects depicted here, gas welding proves the best fix. Follow these steps and study the illustrations. Begin with practicing on old, worn metal. Learn to control the molten puddle, and you can duplicate the methods shown. The results can be very gratifying. If you have an oxy-acetylene torch/welding setup, consider the value of restoring obsolete small parts!
For some parts, what you have could very well be the last one of its kind! An early Chevro
Glass-beading removes surface rust. On non-oxidized parts, bead-blasting and a wash are us
A piece of heavy sheet or thin plate metal can be shaped to reinforce a gap. The 3/32-inch
...Deoxidized, containing zirconium, aluminum, silicon, manganese, and titanium additives,
Welding proceeds with caution. Gas pressure for No. 0 welding tip is set at only 3 psi for
Plate is now in place. Scale has floated from the heated metal, showing just how fragile t