I'm having trouble with a Lee 2-banger that I hadn't had trouble with before. Folds and incidents, with temp ~720 and alloy that hadn't given any trouble before. See the pictures...
Two of the four came the same time, different cavities! ***, Over? Re-scrubbed the mold, re-did it with brake cleaner, boiled it with Dawn, samo samo. My next attempt will be to soak it in either MinSpir or acetone... Any clues? Actually added an ounce of Sn (maybe 6 lbs in furnace), no joy. Carrumba...
(And 3 different furnaces!)