I have an old gas tank that has some light rust in it. Friday (about 36 hours ago) I treated it with Metal Rescue. How long can I leave that in the tank? How do I prevent “flash rust “ when I empty it? TIA
If it's now rust free, it must be coated or moisture in the fuel will eventually damage the tank. You'll get lots of suggestions for the next step. I like KBS coatings as their products are stocked by a nearby AP's store and basically the same stuff by a different company than the other guys, who others will tout- POR . Beware of coatings that don't last! There are numerous threads here of those horrors! Once it's screwed up then it gets tougher to correct. Does Metal Rescue leave a phosphate coating? probably not as the HD listing says non acid and Phosphuric acid does that result. So I have no idea what your stuff left behind ethanol wise?
Chain in gas dryer is my abrasive. Mineral spirits is my rust insulator and rust rinser. Red Kote is when I get serious. < Edit> Forgot to mention laquer thinner as solvent cleaner.
Drain the Metal Rescue when all the rust is converted. For light rust, this shouldn't take more than a day (otherwise, you may need some mechanical action). The tank won't flash rust when you empty it, but it will if you don't dry it quickly after you rinse it with soap and water. Dry it in the sun with a leaf blower or compressed air. Afterward, I apply a light coat of two-stroke oil, then rinse with kerosene when I'm ready to use it. You could also simply fill it with gasoline. Run a filter because some junk will likely remain after rinsing. As long as there's no water in it, the tank won't rust again, so either keep fresh gas in it, or drain it, dry it, and give it a light coat of oil for long-term storage. FWIW, Evaporust, prep & etch, and 911 work just as well and may be cheaper than Metal Rescue. Vinegar works, too.
Factory fresh uncoated tanks were all treated with phosphoric acid.Doesn't last forever but I did such on my Honda and after two years it still looks good.Used tank bought on here locked....had to break in to find the light rust but the phosphoric only treatment took care of it. CLR is phosphoric acid and so are many others.I use the cheaper by the gallon and stronger stuff sold commercially as delimer/de-ruster/de-scaler.Slush around....do not let it puddle and then air dry. The Por kit even comes with phosphoric acid....step 2 after the step1 which is the cleaner?
