[Al Skierkiewicz]

In the first post, you very likely already had a shorted cell. The chargers aren't smart enough to shut off in this condition so it just tries to supply current to charge a cell that will never charge. With lead acid batteries, all excess charge current is converted to heat when the battery is fully charged. (you can only carry a chemical reaction so far.) By my calculations, the 6 amp charger will convert roughly 75 watts directly to heat. That is like having a 75 watt light bulb burning inside your battery case.
Please be careful handling batteries with cracks in the case, vented juice and/or fumes. The acid is gelled sulpheric acid, it can burn delicate tissues (backs of your hand, eyes and eyelids, inside of your mouth, etc.) and will eat holes your clothes. Wash carefully after handling a cracked battery, don't eat, rub your eyes or pick your nose until you have thoroughly washed up. The funny thing is the holes won't appear in your clothes until your next washing.
As to the other dumb things...Please be careful when handling these batteries. If you don't know, ask. PM me if you think it is a dumb question and I will try to get back to you.