you have to aerate the water all the time. you have to break up the steam envelope,and let the pack cool before dumping in the tank i think your temp is to high, if you try and make your own bone charcoal make sure you neighbors are not down wind from you.on your crucible seal the lid and add the piece of paper to use up any oxygen.i have made several crucibles,most like dr gaddy but i do have a short one i used for SAA frames.good luck there are a million different ideas on how to make this work,you have to figure out how to make it work consistently.