One of the best ways to patch the holes is with fiberglass sheeting.
How to fix pin holes in floor pans.
Usually the pans do not rust or need repairs.
If they are few and far between the quickest way to fix pinholes in your floor pans is applying a sealer like por 15.
I would recommend cleaning away the rust with a drill mounted wire brush though rather than grinding because that removes the rust from the surface and pits but doesn t thin out the floorpan.
Do some searching on it as its harzardous stuff but it really stops rust if you have the metal prepped right.
The hole is covered with the fiberglass mat which is then soaked in por 15 paint and allowed to dry.
Fiberglass is by far the best non welding fix for pinholes and other small holes.
What i did was paint the entire floor on the inside of the car with por15.
Most of the time like their name suggests.
This transforms the flexible fiberglass into a rock solid chunk of rust proof flooring.
This is a permanent repair though it s not advisable to consider this a fix for those fred flintstone floorpans where there s more open air than sheetmetal.
However sometimes it is necessary to repair holes in the bottom of the floor pan.
The previous owner had chosen to ignore the small rust holes and just roll a coating of some sort possibly truck bed coating over the front half of the floor and called it a day.
Floor pans are the base metal layer of a vehicle s floor that everything else rests on.
The rest of the pan was fine and in some cases its not worth it to replace the pan just for a few holes.