I did all sorts of tig welding repairs on a food factory floor in sometimes horrible conditions & locations using a scratch start tig & a valved torch. The welds weren't always pretty but they were strong & functional. So there's no need to have HF start to tig weld, sure it makes things easier but its not a necessity.
As for welding cars using tig, did it once for an emergency repair & I had no mig available but never again! Painfully slow, awkward & you have to have everything spotless to get a decent weld. It also has a higher risk of panel distortion than either gas or mig, the best 2 options.
As for welding cars using tig, did it once for an emergency repair & I had no mig available but never again! Painfully slow, awkward & you have to have everything spotless to get a decent weld. It also has a higher risk of panel distortion than either gas or mig, the best 2 options.