If the parts require welding, this should be carried out before anodising. The anodic coating has very high electrical resistance, effectively stopping welding. We recommend the use of 5356 or Al-Mg 5 alloy type welding rods for the best looking results after anodising. In addition, the use of TIG instead of MIG welding is favoured as MIG welding produces very high localised temperatures with rapid cooling leading to structural changes in the aluminium which hinder the anodising and prevent the uptake of dyes. TIG welding typically lessens or eliminates this problem by preheating the aluminium around the weld area and the slower rate of cooling.