What do you mean it never fully burns the image? Do you mean when you go to wash it out, that only part of your image is washing out? If so, then that is overexposure. That could be due to too much time with your set up, exposing your screens to UV light for too long or your films not being dense enough. It could also be bad emulsion, but my guess is, this is a new setup and if I'm not mistaken, Yudu uses capillary film.