Don, If you have the patience and skill to do large open wing bays and turtle decks using nothing but Monokote and an iron, you are truly talented. For me, the "heat it till it almost bursts into flames with your heat gun" technique is all I can manage.

My gun is a super cheap Hobbico model and is slightly adjustable using a rotary vent on the back and comes with a flat pattern nozzle for the front. For monokote I do have the vent as closed as possible for more heat and I do use the flat nozzle as well, again to concentrate the heat. Again, more heat, solved any shrinking problem I had. Ultracote will catch on fire at the temps I used for shrinking monokote.