? about doing patch panel

[jonnyc]

i see alot of picture where someone does a patch(say in a quarter panel or fender,)and they use a spot weld about every 2" or so all the way around the patch.and the next picture you see it's all finished.
do you go back and finish welding up the whole seam?or does the rest of the seam get filled in with filler?or how is this done?
the reason i ask is,i have about a 12"x12" section of my floor i would like to try and repair.

thanks

[craigs73]

you keep tacking until you get all the way around but dont just go in order skip around so you dont warp the metal then when thats done you grind the tacks down

[mikey]

I go all the way around with tack welds. Then I grind them down and repeat until it's welded solid. The grinding helps to eliminate the warping. When the welds are ground down it doesn't require as much heat to get good penetration. The welds are thicker so more heat will be needed when joining tacks to tacks. So by dressing up the tacks you are able to maintain a consistent thickness being welded.