Yeah; tacks every ~20mm, grind the tacks down, then weld 20mm at a time going over the tack, allowing for cooling and avoid concentrating the welding in the same area.
In hindsight I would have plug welded some other bits of the patch to the car some more before I did the long weld as I think not doing this encouraged some of the distortion I got.
In hindsight I would have plug welded some other bits of the patch to the car some more before I did the long weld as I think not doing this encouraged some of the distortion I got.