Ok so I bought an 25+ yr old 40' shipping container cheap as a workshop. The main immediate problem is the roof in one area that has obviously had rain water pooling on it for some 10+years with the Ozzie sun bearing down onto it relentlessly. From inside I noticed a single rusty blister 2" OD with evidence of a small leak below. On the outside of this area, there is an area about 2' x 1' with severe rust. By this I mean multiple thin layers of steel rusting come off when nudged by a screwdriver. I created two small holes (1" sq) easily so then stopped. The container steel is about 0.125" thick - maybe more. I only need to keep the container for another couple of years or so welding is uneconomic. I am thinking to 1 Get a paint scraper and gently remove all loose flaking rust. 2 Apply some rust neutraliser from above and below and allow capillary action to get it into the smallest of crevices (phosphoric acid from memory?) 3 Wash off any residues of the acid after a few hours. 4 Apply a rust priming paint that will further neutralise any rust 5 Apply a two pack epoxy filler compound all around the rusted areas from above and below Would be interested to hear of any ideas as to what I could do to stop the rust from progressing and rain leaking in?