DIY inverter battery tab spot welder

[Refrigerator]

I had the crazy idea to build an inverter battery tab spot welder.
First test was just hooking up an old ATX PSU to a custom transformer, which yielded some results.
Even managed to make a couple spot welds before the half bridge blew out.
Then built a two switch forward converter and a more calculated transformer but started noticing problems.
First problem was that any tangible current output would only be available right at the transformer, but at the end of the welding leads i would get basically nothing.
Seemed perhaps that my output voltage was too low and could not overcome the total resistance in the loop.
Next i had to consider the inductance of the leads and found that they attenuate my output massively.
Please keep note that the output is not rectified. The EMI from this thing must be nuts, but i digress.
Now i have ordered some IGBT's to build a proper power stage that can handle at least 4kW.
From my estimations my output leads can have a minimum of 100nH inductance and 400nH max, so i'll have to keep my cables tightly paired together to minimize the loop area.
Tbh i'm not sure how practical this project is but it's a fun exercise (in futility perhaps).

What do you guys think about this?
Also i'd like to build a low-ish frequency inverter that uses laminated EI core instead of ferrite.
I'm thinking 1kHz should be an ok-ish switching frequency to test things out. Imagine the noise this thing would make.

[Decapitator]

You are overthinking this. Look into building a "capacitor discharge welder". There are plenty of ideas on YouTube to start with. There also exists a two part article that was originally published in the March and April of 2022 issues of Silicon Chip magazine. The same article was republished a year later in Practical Electronics (EPE) magazine. I consider the project described in that article to be overkill for spot welding thin nickel tabs to 18650 cells without burning holes through either, but the basic approach is sound.

[tautech]

https://www.eevblog.com/forum/projects/guesses-on-what-i-am-attempting-here/