There are lots of differant rust converters...
You can even get a couple of types at Wal*Mart.
Most converters require the lose rust to be removed with a wire wheel/brush first, then a liberal coat of the converter applied.
it does not work well on clean metal, so we're just talking about the loose
scaly stuff. You can cut out the really bad parts to good metal.
When it is dry, it has converted the rust (iron oxide) into iron tannate an inert black substance that you can prime and paint over.
Because the stuff seals out the moisture the rust isn't supposed to return.
Painting it really helps though.
I have a buddy that worked in a paint shop... and he swears by the stuff.
They called the stuff "rust mort" and you could probably get a better deal on it at any automotive paint supply or possibly a body shop as well.
I've used it on my bump with pretty good results... especially in those areas that are hard to get clean.
Like the area inside the cab above the doors and around the top on the inside of that cab that are really prone to rust and are hidden from sight behind the headliner until they rust through...
It comes in both brush on liquid and in spray cans...
To patch the holes, try "fiberglass inpregnated" resin (bondo) applied from inside the cab. You can use a nylon or plastic spoon/knife to push the stuff thru the holes.
On the outside, just use your finger to spead the stuff that has oozed through the holes smooth until it fully cures and can be sanded smooth...
Nice clean patch with very little stuff in the gutter itself...
Another patch method for rust through like that is called leading, where you actually melt lead like solder into the the hole and make a patch...
Alot of old skool rodders used that method for doing custom work like frenching... I've never done it myself, but have seen it done a couple of times.
KaptnKA
S
Does anybody know of a POR 15 like product that can be bought at the local DYI establishment? I'm looking for something to either stop or slow rust until I have the time and money to go in and fix it the right way. I just don't want it getting any or too much worse. As you can see in the pi, this is what happens when a previous owner tries to fix rust with Bondo! 
Steve - Caloundra, QLD, Australia 