How to Reduce Expulsion in Resistance Welding
Resistance spot welding is a process by which two pieces of metal are pinched together and fused by passing an electrical current between them. The electrical current turns the metal into a liquid state, at which point expulsion can occur. Expulsion is the shower of sparks that you see shooting out from between the electrodes during the resistance welding process. It is caused by incorrect adjustment of the welding machine for the material being welded. While expulsion cannot be completely eliminated, careful tuning of the welding machine can significantly reduce expulsion from your resistance spot welds. Does this Spark an idea?
Things You'll Need
- Safety glasses
- Leather gloves
Please enter your 10 digit phone number only.
A link to this article has been sent to the phone number provided.
Instructions
-
-
1
Dial in the settings for the resistance welder. There are two dials. One sets the pressure of the clamps and the other sets the flow of electricity.
-
2
Insert test sheets of the correct size material between the clamps of the resistance welder, and then put on your gloves and safety glasses.
-
-
3
Activate the resistance spot welder to initiate a test weld and observe the amount of expulsion thrown from the weld. Acceptably low amounts of expulsion are between three and four arcs. More than this indicates excessive magnetism between the resistance welding clamps.
-
4
Dial down the power of the resistance welder while maintaining the clamp pressure on the work piece. Move the test weld metal to an unwelded portion, and then activate the welder again. The expulsion should be noticeably reduced. Continue reducing the power of the welder incrementally until the spot welder is dialed in, and the expulsion is at the ideal level.
-
1
Tips & Warnings
Always wear safety glasses with side shields when working with resistance spot welders. The expulsion even in small amounts can severely injure your eyesight.
References
- Photo Credit Photos.com/Photos.com/Getty Images
