Walked thru portions of an Aluminum Bike build with Mike Zanconato of Zanconato custom cycles. Aluminum TIG settings using a Miller Dynasty 280DX and expansion card with amplitude settings
TIG Welding an Aluminum lap joint uphill with nothing to prop on but the hot aluminum.
Mike Zanconato shows Tips for Silver Brazing bike lugs fittings. These same tips and techniques apply for most any silver brazing task.
There is a bunch of data that states 4130 chromoly tubing .120" and under does not required a preheat or post heat treatment. But a preheat won't hurt.
