Carlisle Tire & Wheel's old welding equipment produces spatter (left), while the new equipment eliminates spatter (right).

Carlisle Tire & Wheel improved the quality of its hub-to-plate weld.

Carlisle Tire & Wheel Co. (www.carlisletire.com) makes low carbon steel wheels, and takes pains to make them look nice to meet customer demand.

One particular problem the company had was that it used large volumes of anti-spatter solution at its Slinger, Wis., facility to eliminate weld spatter from its finished wheels. The company bought anti-spatter solution by the tank load and ran parts through an anti-spatter tank just prior to welding to facilitate removal. The result was a sticky mess. Antispatter solution covered the welding cell, clogged MIG gun nozzles and got inside the rectifiers, says Doug Karlin, Carlisle's production engineer. This mess was a mere annoyance compared to the real problem: the cost of maintaining quality. "Trying to weld through a liquid is not an easy or smart thing to do," says Karlin. "We often had too much or not enough antispatter solution." With too little solution, spatter would stick. With too much solution, pinholes would form in the weld.

The pinholes had to be repaired because they caused problems with painting. In its effort to change its old short circuit MIG process and conventional MIG systems, eliminate spatter and increase quality, the company installed XMT 350 CC/CV, multiprocess power inverters from Miller Electric Mfg. Co. (www.millerwelds.com), controlled short circuit (CSC) MIG weld process controllers from Jetline Engineering (www.jetline.com) and changed to BR6 coppercoated filler wire from Hobart Brothers (www.hobartbrothers.com). Once implemented on Carlisle's 6-in. wheel line, the new process eliminated the need for of anti-spatter solution while sharply reducing spatter. The problems with pinholes disappeared, and the company saw reduced energy costs and wire consumption. Each element of the new process has made its contribution of improved quality, Karlin says. The controller from Jetline combined with the XMT 350 inverter produces TIG-quality welds at MIG travel speeds, says Joe Fink, a Miller welding engineer, and Kevan Kokkonen, a Miller district manager.

The controlled short circuit process has a high speed, precision stepper motor that controls the movement of the wire in and out of the weld puddle, producing a short circuiting process that eliminates the explosive "flaming batons" of filler wire that creates spatter in traditional short-circuit MIG welding. Eliminating the need for anti-spatter solution eliminated quality problems related to the pinholes, and testing has shown that welds made with the new equipment are stronger than previous welds.

Harlan Janssen, Carlisle's quality/engineering supervisor, attributes the increased weld strength to the minimized heat-affected zone from the CSC process. Other benefits include consumable consumption. Carlisle switched its wire packaging system to Hobart's Robopak 950, and Harlan says the pack reduced reject rates. "Previously, we had to apply wire straighteners to remove the cast, which was a problem toward the end of the spool. With the Robopak, the wire is straighter so it makes better contact."