Wire tip keeps burning up

I have a Lincoln 460 power wave welder running a robot arcmate 100! Rj3 controller weld sequence is putting tacks on washer rings. And the other side welds a half moon on web.. the problem I am having is on the tack sequence. Sometime the tip burns up have to change tips 5 times in 2 hours. What can cause this thanks

Okay thank you. I did see one to close adjusted it so far so good but the cooling thing ti cool the tip nozzle isn't working. Just found that out ..