Results of tests show that a slowly rising condenser-discharge preheat current with a rapidly rising welding current afford no less expulsion than a rapidly rising welding current alone, and was inferior to a slowly rising welding current alone. In one case using slowly rising current for preheating and welding proved beneficial although generally, utilizing a raised electrode welding force to decrease expulsion was more practicable. Postheating had no effect on sheart strength until the current sufficient to remelt the welds, which greatly increased the weld diameter and shear strength.