Repairing Aluminum Fuel Tanks

I recently picked up a couple of aluminum fuel tanks for my Peterbilt 351. The tanks came off a late 80s Kenworth and where the tanks sat on the saddles there is corrosion. The only spot it is corroded is where the saddles sat on the tank. There are some pretty deep holes and one place i think there might be a pin hole leak but there is no place where you can see all the way through the tank. I am looking for a solution to this problem so i don't have to get new tanks as the budget for this project is pretty tight. I have a spool gun for welding aluminum but i don't think it would do much good with the corrosion. I am open to any ideas that people might have i am in high school and this is the first project of this size i have done. Any ideas would be helpful to me, Thanks.

 

I found some stuff called por15 fuel tank sealer that seems to be for that. Would that be something i could do myself.

 

Okay, just out of curiosity how much did that run you to have done because that may be an option.

 

Okay, well i may try that i like the welding the strap around the tank better but I'm afraid it may be too much for me to afford.

 

What would be the best way to clean out the holes because some of them start and then get bigger under the surface of the metal so i cant get all the way down in them.