I have found that if I heat to 180, add FO at 175 and pour slowly immediately after stirring in the FO, I get neither air pockets nor sink holes. But I usually get a small circular crack around the inside of the container, so you still need a heat gun or second pour. IMO, this wax is worth testing because it has a very good cold and hot throw, the best out of the 5 soy waxes I've tried. BTW, I wrap a kitchen towel around my containers to help insulate them as they cool, which really helps with the sink holes. I do not preheat my jars.