just pour a few gallons of POR 15 in there...should do the trick.

 

I figured, take off the front section, clean out all the garbage, patch any spots that may need it, put a nice thick coat of POR-15 in there and seal it. than you'd just have to find a way to get some on the spots where it gets welded back in and you'll never have to worry abou tit again. Or you can take it one step further and spray it with a thin coat of rhino lining.