Hello All,
I have never used creosote bottoms boards nor do I plan to in the future
but several beekeepers have wanted me to ask the list a question.
A large area beekeeper  had around 2000 bottom boards of his own design
coated with cresote at a local( out of business now) cresote plant. His
operation begain to experience trouble with hive death after he started
using the bottoms. The mites had hit so most figured the mites were the
primary problem.  After the beekeepers death many of  the boards were sold
and many other beekeepers have said bees don't thrive on those cresote
bottom boards he had made up. Most said once they remove the board and
replace with a non cresote board the hive condition improves. Dwindling and
not thriving are most often described.
question:
Was the cresote plant mix wrong and this is a isolated incident or have
others had or seen a similar problem?

From the dictionary:
Creosote- an oily liquid obtained by the distillation of wood tar and coal
tar, used as an antiseptic and preservative.
Sincerely,
Bob Harrison
Odessa, Missouri