Weld Chatter in tube scarfing applications:
Weld chatter is the result of not being able to scarf the weld bead properly enough to achieve a good, clean tube. The OD scarfing tool “chatters” and produces a finish that appears ”ribbed” on the OD of the tube. Here are some tips for reducing weld chatter.
1. The OD scarfing tool or OD scarfing ring should have a slightly larger radius than the OD of the tube.
2. An “ironing pass” can be used after the scarf stand. This stand “irons” out any imperfections the OD scarfing tool misses.
3. On mills with induction welding, reposition the induction coil away from the weld rolls to help temper the edges of the strip by preheating them before welding. The resulting material is softer and thus easier for the OD scarfing tool to cut.
4. The scarfing tool relief should be set at an angle of at least 11 degrees from the work piece. This prevents the OD scarfing tool od OD scarfing ring from dragging on the tube.

Weld Chatter: Other causes
1. Not enough weld bead for the scarfing tool to cut.
2. Not enough weld power to forge the weld properly.
3. The OD scarfing tool stand is located too far from the weld box causing the weld bead to cool down and not be cut smoothly.
4. The tube is jumping at the scarf point because there is no support plate or support roll under the scarfing tool.
5. Incorrect OD scarfing tool radius.
6. Dull, chipped, or worn scarfing tool.