Floorpan rust

[Curt Hayes]

Pulled the carpet out tonite for a paint job I'm getting done and found a rusted-through spot in my floorpan, on the right side, next to the tunnel. What would be the right way to fix this? And what would be a wrong way that might last a while without causing too much trouble? The hole goes all the way thru to the heat-shield under it.
Advice appreciated.
TIA,
Curt

[browntown]

grind clean, weld small patch, paint to protect on both sides. I had a hole from a stud under the car rusting up into the floor pan. I'll tell you now that metal is thin and hard to weld.