hello ive been welding since I was 18 years old only mig and stick I would like to have a go at tig some time in future.ive built a few land rovers but my main passion is mercedes unimogs of which i have rebuilt many and modified some as well. I have a problem with my cebora 180 mig its about ten years old and has served me well only one morning I swithched it on and the gas was going and then when I squeezed the trigger the wire speed was at full regardless of the knob possition and the wire is live all the time if anyone can help.here are a couple of my mogs its the cabs that rot the chassis are nine mm thick Many thanks oi and my landrover trialer