Vertical welding of thick aluminum members

A method of welding a substantially vertically oriented pair of aluminum members, each of said members having a thickness of at least about 0.5 inches, and each of said members having a land defining surface and a groove defining surface, the land defining surface of one said member being positioned against the land defining surface of the other said member, whereby the groove defining surface of one said member cooperates with the groove defining surface of the other said member to define a substantially vertically oriented groove, the groove defining surface of each said member being characterized such that said groove has a depth of about 1/8 to about 1/2 the thickness of each of said members and an included angle in the range of about 45.degree. to about 75.degree. , which method comprises:

• placing a gas-metal arc torch having a consumable aluminum electrode and means for supplying a shielding gas therearound with said consumable electrode in said groove, generating a welding arc characterized by a weld current ranging between 200 and 400 amperes and an arc voltage ranging between 20 and 40 volts, and moving said torch substantially vertically along said groove while holding said torch at a backhand torch angle ranging between 1.degree. and 25.degree. and feeding said consumable electrode and said shielding gas at rates effective to produce weld metal in said groove having an outside oxide support skin which acts as a sole support for said weld metal during its solidification, said torch being moved at a rate which ranges between 3 and 10 inches per minute and is effective to substantially fill said groove with said weld metal in a single pass.