Revive old car battery epsom salt

battery had before i did anything to it not charged for a little over 3 months the battery boils acid everytime it charges. and had very little acid covering the plates. UPDATE 2/13/13 battery has been off the charger for 24 hours swapped battery in my truck and starts right up. UPDATE 2/15/2013 battery sitting in my truck for 2 days without being started in below freezing temps had truck started right up with no hesitation. UPDATE 2/23/13 i had to jump it with my charger a few times. i