I just received an oxalic acid vaporizer from Heilyser Tech. in Canada.
I'll be trying it out within a week. This model uses an air mattress pump
to deliver vapor, rather than directly heating in the hive. Heat source is
a torch. Looks very simple to use - the manufacturer insists on about 2-3
minutes per hive, with no risk of heat damage within hive, eliminating the
need for extra hardware for polystyrene hives. I'll provide pics and
observations after I try it.
Todd.