i bought the 56 dollar jug of 911, makes 16 gallons of stuff they say. it sure works good, but i was disappointed by how fast the solution looses its power. i made a 2x4 frame 2' by 40" and lined it with plastic. then did the recomended mix of 8 oz per gallon. the plan was to do some sheet metal parts i'm afraid will warp if sand blasted. first item in for a test was a 34 windshield frame. what i hoped for was to soften up the rust enough to get it apart. i needed the corner brackets, and the hinge brackets, and i wanted to see what it did to the chrome finish. i was hoping to do the seat base after that, but the solution turned black and stopped working just from the one part. 8 gallons of mix it took to cover it, and again my box was made big enough for the seat pan, but half the 56 bucks did not completely clean the windshield frame, and all screws had to be drilled out. next i filled the same box with about 3 gallons of molassis, at 9 bucks for 5 gallons, and put in my header above the windshield, and the cover over the transmission, and now about a month later the parts are like new. very slow, you must plan ahead, but it keeps its strength for ever, just add another part when its time. evapo rust, and rust 911 are wonderful things, but keep it for very small parts imho, skip forgot to mention the chrome part. this frame i put in was not good, but i have one that is good enough to use and wanted to see what the 911 would do to the chrome. where the chrome is good it had no effect. but where the chrome had started to peel at all it would lift it off the surface as there must have been rust forming under the chrome. so my opinion-keep the old chrome out of the stuff