plan on never using the truck in the rain and selling it before it needs more metal patching
coat the inside of the patch pieces well with high zinc weld-thru primer before you weld them in - afterwards spray/slop/pour some rust prevention like POR in the bottom via the inner panel hole, and increase the size of the OEM drains
all you have to do is improve that bottom few inches over the original no-treatment-at-all and it'll last longer, but don't think that you can totally prevent deterioration if it's going to be really used in all weather, the welding residues that you can't clean out will eventually bite you
Bill
