Oil Tank Cleaning

[VintageTwin]

I put 26,000 mi. on this rigid frame tank. I used old tank lines, cleaned, fluxed, smashed and soldered as caps. Put a pint of Klean-Heat (kerosene alternative) in with 7 nuts of various sizes and shook it around alot. Not too hard to dent the can. Stood it on end in the hot sun to soak for a few hours, shook it some more. Emptied the kero on a piece of cardboard to see what came out. Mostly rust colored metal grains and bronze flecks. None of this ever showed up in my external oil filter. A year ago, I removed the filter cup (to see if I actually needed to change the oil in the tank), and there was hardly any metal flecks in the hornet's nest cannister. I surmise that alot of the metal drops to the bottom of an oil tank, and just sits there. The oil flow out of the bottom of the tank is not enough to pull the bronze particles up off the bottom. It took three pints of rinsing and nut-shaking to get the solution to run clear.