David-aviator
Well Known Member
Some time ago it was reported that ethanol may be corrosive to aluminum. At the time I looked inside the fuel cap opening and observed that my tanks appear quite new and shiny after using up to 10% of the stuff with mogas for some 4 years with the Subby.
Today I arrived at the point where it was time to check out the fuel system with the Lycoming install but before pouring some 100LL into the tanks, which have been empty for a few months, I had another look at the condition of the skins. Wow, they are not new and shiny looking anymore.
There was a film on the skin surface that could be removed with a rag on a stick. The substance that came off with the stick and rag was black. After fuel was poured in, the tanks looked new and shiny like before. The film, whatever it is, is only visible when the tank skin is dry.
I do not know what the film is. It could be corrosion or something different. In any event, I am off the ethanol kick. From here on it will be mogas without the stuff or 100LL.
Today I arrived at the point where it was time to check out the fuel system with the Lycoming install but before pouring some 100LL into the tanks, which have been empty for a few months, I had another look at the condition of the skins. Wow, they are not new and shiny looking anymore.
There was a film on the skin surface that could be removed with a rag on a stick. The substance that came off with the stick and rag was black. After fuel was poured in, the tanks looked new and shiny like before. The film, whatever it is, is only visible when the tank skin is dry.
I do not know what the film is. It could be corrosion or something different. In any event, I am off the ethanol kick. From here on it will be mogas without the stuff or 100LL.