nedflanders
New Member
- Messages
- 7
Hey, guys, hope someone can help. I'm having a spot of bother with a customer's DC inverter I am using to do some TIG welding for him. The machine in question is as per the heading, a Thermadyne DC inverter 140 (not sure if anyone is familiar with the brand?). Welding on thicker material is fine (3mm and up), but when I try to weld on thinner stuff, it simply doesn't want to play along. With the amps set to 20 (the lowest setting on the machine) and using a #2 gas shroud (correct term?) with a 2.4mm tungsten sharpened correctly and running pure argon set on 8L/h, it burns through 1.2mm 3CR12 plate within seconds. It is very difficult to get a decent bead as if the amps are set way too high. The weld is very undercut and also very black and the HAZ is around 3 times wider than what one would expect. I went down to a 1.6mm tungsten with no noticeable change in the result. With a 1mm tungsten it is still almost impossible to run a weld without burning through the 1.2mm plate. I have played around with different flow rates and kept the tungsten protruding as little as possible, but the problem persists.
It is as if I have the machine set up to around 95 amps or more, that is how hot the arc is and how quickly it melts the material. We had the settings on the pc board set to minimum and the adjustment pot replaced, but to no avail.
Do any of you have an idea what could be causing the problem?
Thanks in advance....
It is as if I have the machine set up to around 95 amps or more, that is how hot the arc is and how quickly it melts the material. We had the settings on the pc board set to minimum and the adjustment pot replaced, but to no avail.
Do any of you have an idea what could be causing the problem?
Thanks in advance....