Thickness of Vitesse Mk1 2Litre, tubular seat frames

[daverclasper]

Hi. If anyone knows the gauge please. I assume around 2mm?.

I was replacing a diaphragm and noticed a few previous (post factory) welds  of seat base frame, to main frame have failed. An idea of the gauge would be good for base welder settings.

I attended a basic mig course and got ok at the more basic joints, (butt, lap, fillet, etc, with sheet metal) though this looks more challenging.

Wish me luck and any tips for this type of joint would be great.

Thanks, Dave