I have one of these machines. When using it with MEK in the atomiser and distilled water and Potassium Nitrate in the cell, the Torch tip, a no 18 goes red hot with flame going out and backfiring. Any ideas what is happening? I tried it with meths and Acetone in the atomiser and it did not do this, but the flame was a little whisper, with not a lot of heat power. I have read the manual.