could be particular acid transpiration, immersion in alcohol (among grass root paneristi, it was customary to "baptise" new aquisitiond in beer or wine etc) I have to be honest, I was not given a "manual" with dos and don't. Just told not to do silly things with it AND avoid any direct contact with alcoholic substances. My composites are "safe queens"
My 232 was (and still IS) well used.......... 