How to Weld Chrome-Moly

Clean the materials. The first step in any welding job is to make sure the steel is clean and free of oxidation, paint or oils. You can use paint remover or a wire brush on a drill to effectively remove any existing paint or primer, as well as any oxidation. Once the chrome-moly is bare, acetone is an effective cleaning agent; but alcohol will work fine as well. Do not use the spray-on type brake cleaner because the welding process creates fumes from the chemicals that can be fatal. Once the material is clean you can begin to weld.

Weld the chrome-moly. Always wear the proper safety equipment when welding, which includes welding gloves, a welding hood and long-sleeves at the bare minimum. Chrome-moly can be welded just as you would weld any other mild steel tubing. Set the welder correctly for the thickness of the chrome-moly. MIG units usually have a chart inside the wire spindle door that indicates the correct settings for each thickness of metal. Place the wire tip about 1/4 inch above the chrome-moly surface and pull the trigger on the MIG gun. Move slowly, ensuring proper penetration and a good, solid fusing inside the weld.

Clean up the welded area. Once the weld is complete, you may use a grinder or dremel to remove excess steel around the weld and then paint it. If you use flux-core wire, be sure to take a wire brush to it first to remove any welding slag that may have built up. Let the chrome-moly cool completely before adding any primer or paint.