For the .040, to control heat input, try around 30-50 for pulses per second, background current, and duty cycle. For the thicker stuff I wouldn't use pulse at all. However, some people like to use a slow pulse to keep their timing and travel speed consistent. For that application dial the pulses per second to match your desired dip rate, around .5 to 4 pulses per second. Then dial down the background current and duty cycle just enough to you can clearly see the timing.
Long arc, short arc, heliarc and in-the-dark!