ORIGINAL: mkjohnston
This guy at an LHS told me not to use marvel mystery oil in my engines as this will glue the piston to the sleeve. It turns out that this guy and his dad created an after run oil and that they are still getting paid for it. I used to use a 50 50 mix of atf and mm and this worked great but someone told me to use the MM Airtool oil which I use now. The only thing I've noticed is when you start your engine for first time it smokes allot. Michael
This is true of Marvel Mystery Oil. It's happened to me - it hardens into this hard red stuff. But Marvel Airtool Oil is something altogether different and is used by many modelers, including myself. The caveat is - it's got ignition retardants in it (makes sense..) so it might not be the best stuff to use in model diesels.
Not particularly easy to find, though. Compressor oil is, but I've been told it's not the same thing as air tool oil. Surely other people make air tool oil, not just Marvel?
Iskandar