Advanced Aluminum TIG Techniques

Aluminum fillet joints require meticulous cleaning—both mechanical (stainless steel wire brush dedicated to aluminum) and chemical (acetone wipe) to remove oils and hydrated oxide. Unlike steel, aluminum should never be ground with a wheel used on ferrous metals because embedded iron particles cause galvanic corrosion. Joint fit-up must be tight because aluminum's high thermal conductivity pulls heat away from the root, making it difficult to achieve penetration across gaps. A 3/32-inch maximum gap is the practical limit for single-pass fillets.