a wine cooler belonging to a friend of a friend of the owners showed up in the shop. this is a small cooler from a box store , maybe 20 bottle capacity. it no cool. i put a schrader in the process tube and started to play with it. how does one weigh in 1.5 oz of 134a. my electronic is + or - .5 oz. my plan is to charge it slowly until the suction line stops frosting and the case cools. anyone have any ideas?