Hey Baz,
The current method is to simply draw the heated air from the top/back and blow it in at the bottom/back. I noticed that on a large tank I was trying to coat the ends were not curing at the same rate. It was obvious there were "cold" spots in the oven.
A better way may be to create a motion of air/heat movement in the oven using a different method. The idea involves a design I'm not quite ready to make public just yet. It may be patentable.
