Stick to TIG welder

TIG welders on the online stores are ~ 2x the price of a stick welder. How hard can it be to convert?

Scratch start

Tungsten is worn down quickly from the scratch starts.

Wastes a lot of gas with manual gas control.

Reverse engineering

Worked out how to turn the welder off.

HF start

Really big toroid. Wind thick wires. Sparks! I did add two primart coils (yellow and green) pictured above. Both created similar looking arcs so I think core saturation is more of an issue here.

It follows this schematic.

The capcitors on the welder side are effectively shorts to the high frequencies of the sparks, and a bleed resister across the caps. The HV source(DC) are modules off the ususal e-commerce sites with a fair bit of built in capacitance from the voltage multiplier. Spark gap is about a 4mm gap in air.

Gas control

Just an off the shelf 12V solenoid valve works pretty well. Used an arduino for some quick post flow after the weld current stops to keep protecting the weld.

Results

It's a working tig, the HV start is a little loud and I have not put in logic to stop the HV once the arc is struck. Not sure how much that affects the welds. But happy to report the welder has not suffered any damage from this addition.