No! More hz doesn't mean more heat! Because you can't think of a pulse of a set length! If you have a 50% duty cycle at 100hz, that's a pulse 0.005 seconds long. If we keep the duty the same, you can't have anything but 100hz with 0.005 second pulses at 50% duty cycle. If we ran it at 500hz, and 50%...

I'm not ignoring it, in fact I did mention it in lay mans terms "for a very brief period of time..." The power loss difference when looking at 100hz vs 500hz is insignificant. A quick google searth for MOSFET and the very first specific device is this one: https://www.sparkfun.com/products...

That is not correct. As you increase the frequency, the off time also goes up in line with the on time! If you change nothing but the frequency the over heat load is (in theory) the same. However there can be switching delays in the devices as they go from fully ON to fully OFF. In these in between ...

Well I found the problem.... Cheap nasty gas lense. I thought I was putting in a CK 1/16 gas lense, but it was a cheap far eastern part I had knocking about. I tried my 3/32 CK part and hardware, problem gone. Then I found my 1/16 CK part still in the bag. The difference is night and day when you lo...

You don't have a clear laquer on that steel do you? I've had that with some steel purchased from "retail" outlets and it makes a mess if you don't clean it right off first.

I figured the gas wouldn't be contaminated as soon as I did a little more research on it in general. I will certainly see if I can get a second flow meter on the torch to compare with the one of the bottle. The torch has been hanging around for a long while since I purchased it from my local welding...

Lack of pre flow.

In the past I've used cheap machines with no pre flow, so the solution was to hit the switch off the work piece to start the gas, then go to start the weld with the gas flowing nicely.

Well after a little research I would have to conclude it was not enough purging of the new hose and torch assembly. Any air or oxygen would be homogenised in the argon it would seem. Plus a google of purging brought up Murex manual recommending a 15 minute purge of a new torch assembly.

I was practicing some TIG late yesterday after all the real work had been done, and also changed my torch. I had real problems trying to weld some 16g low alloy (T45) steel tube. I put it down to not fully purging the air out the hose of the new torch. SO I ground it all back, and ran the gas throug...