How to Prepare an Electrode

Generate a ball tip on the end of the tungsten welding rod. Choose the balled tip profile on your welding rod for AC welding. Once you strike the arc, the tip will form a small ball on the tip where the tungsten melts. Do not allow a large ball to accumulate on the end due to the possibility of it coming off as you weld and contaminating the seal. The rule of thumb for ball size is to limit the diameter of the ball to one and a half times the diameter of the welding rod you are using.

Mount a silicon carbide or diamond wheel on your grinder and use it for the grinding of welding rod tips. Tungsten is brittle and hard so take care when grinding the tips of the rods. Orient the tip of the rod parallel to the face of the wheel. The movement of the wheel is in the direction of the long dimension of the rod. Never orient the rod in a perpendicular orientation to the wheel. The brittle nature of tungsten makes it prone to shattering when ground in the perpendicular orientation.

Form a point on the tip of the welding rod using a grinder when working with DC power. Low to medium DC arc welding uses a sharply tapered end on the electrode. The sharp point aids in directing the arc to a point where the weld will occur. Make the length of the taper on the end of the rod about 2.5 times the diameter of the welding rod. The length of the tapered region determines the heat directed to the point of the rod. When working with thinner material, you can reduce the heat to prevent burn-through by increasing the length of the taper.

Truncate the end of the taper when working with high current DC power. Flatten the tip of the taper with the grinder. Using a truncated end helps to avoid part of the bead falling into the weld and causing contamination. The blunt end concentrates the heat and works better for thicker material. Very light grinding of the tip will form the blunt end. Too much pressure placed on the rod as it contacts the grinder may cause the rod tip to break off.