Experienced fabricators know that each material has unique challenges during the fabrication process. However, some hobbyists may not know the subtle differences that must be considered when working with different metals. This article discusses four tips that can help hobbyists to repair cracks in aluminium products successfully.
Preheat the Metal
Have you ever been dismayed when a crack you were repairing in aluminium widened during the repair process? That scenario may have been caused by the high rate of expansion that aluminium exhibits when it is heated. The trick in fixing the crack in aluminium is to preheat the metal before you start welding over the crack. Preheating ensures that the material will have a uniform temperature during the welding process. Consequently, the weld area will not expand and widen since it will be at the same temperature as the rest of the surrounding material.
Drill Holes in the Material
Another way to prevent cracks from expanding as you repair aluminium materials involves drilling holes at the ends of those cracks that you wish to repair. Those round holes help to distribute the stresses of the welding processes evenly so that additional cracks do not develop in the material. You can then direct a weld bead on each of the round holes that you drilled so that your component remains blemish-free after the repair process.
Pay Attention to the Oxide Layer
Aluminium immediately forms an oxide layer on its surface once it is exposed to air. That oxide layer can prevent the crack from mending as you weld the material. You should therefore remove the oxide layer before you start welding over the crack in the aluminium. Use a burr or grinding wheel to remove the oxide layer. The crack will then be mended once you start welding.
Use GTAW During the Repair
The welding method that you use also plays a key role in ensuring the success of repairing a crack in aluminium. GTAW is likely to offer better results than the GMAW technique. This is because GTAW allows you to increase the amount of heat that you can use during the welding process. This extra heat is necessary because aluminium is an excellent heat conductor that quickly spreads the welding heat to the surrounding metal. Extra heat enables you to weld successfully despite this conductivity.
Cracks in aluminium will never present challenges to you if you implement the suggestions above. Consult professional fabricators in case you still experience problems as you fix those cracks using the techniques above.