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Cutting and Welding Techniques for Steel Tubes

Steel tubes and pipe piles are widely used for construction purposes, for instance, in foundation of building, bridges and port facilities. While welding process for these structure remains similar to other metals, the technique may vary depending upon the type of steel tubing. Hence, it is necessary to do some preparation work to achieve a quality weld.

Cutting
Cutting steel correctly is an essential requirement for completing a quality weld. Based upon the thickness and width of the tube, you may use a stick welder or wire cutting unit for precise formation of the ends. This makes the welding job much easier. Cut the tubes very close to the 90 degree or 45 degree angle as per the requirement of the joints. Measure and re-measure, the work piece to be welded before making the first cut. This will considerably save the time as well the material from being wasted.

For thicker tubing, it is recommended to cut a V notch at the end. The V notch gives the welder perfect grip over the tube and effective hold over the pieces together.

Preparation Work
Once the workpiece or the tubing is cut to a defined angle, it is the time to grind the ends for removing the burrs that may have been deposited while cutting. Remember to remove paints and rust from the surface of the tubing. The ground clamp and arc tip must be placed on clean, untreated metal to achieve strong weld.

New tubes come with a coating of oil to prevent rust while stacking. Apply alcohol and rub with the rag to remove the oil from the surface of the tubing. This will make the piece ready for welding or painting.

Welding
Lay the work piece flat on the table and secure the piece by clamping it before welding. Position the ground clamp in proximity to the weld arc. On thin metal tubing, start by welding an inch around the circumference, allow the piece to cool for sometimes. Continuous welding will produce heat that will cause the tubing to warp, thus resulting in large gaps that need to be filled or redone completely. In the second attempt, start from the baseline, and then fine tune from there. Remember too hot weld might blow the tubing, while welding at a low temperature would not produce enough heat for the task to be accomplished.

Slowly remove the welding tip away from the tubing as you weld. Inspect the welded pipe or tube for pin-size holes and reweld to achieve a smooth finish. Allow the tubing to cool down and clean the weld with wire wheel or brush.