In article <002101c2843d$42c6ee00$3bac58d8@BusyBeeAcres>, Bob Harrison
<[log in to unmask]> writes
>I do see many problems with the poly hive in the application we use and do
>not believe the poly hive will ever be accepted by migratory beekeepers.

I can see that very well in your major league migratory situations where
the bees can be on the truck for what, to us, are extreme periods. They
would all overheat unless you had some remarkable ventilation system. We
only move them 150 miles at most and we NEED to do something about the
heat problem.

>
>Walter Kelley asked my opinion of his hard plastic beeware years ago. I said
>I would be afraid they would warp over time (yes I bought a few to try!).
>Took longer than I thought but the tops and bottoms did all warp after a
>long time.

Thats because, despite appearances, many things we see as solids are
actually fluids. May take 100 years to become apparent, but fluids they
are.  Glass is an example, as are many plastics. I have read of the
glass in very old windows (we are talking several hundred years here)
being thicker at the bottom than at the top due to the very slow sagging
which occurs. I would hazard that this may be the case too with
thermoplastics, where, given enough time, they will sag under their own
weight, rate varying only with temperature.

>   Would the poly hive last a 100 years as Murray suggested
>without warping? I do not know but have to wonder.

Given the above I would expect that in extreme time scales the answer is
probably yes. However, this material is mainly gaseous, is very light,
and just by the mechanics of it, one of the main forces acting on it to
make it sag is radically reduced, to no more than 10% of the force were
it solid plastic. With it being mainly bubbles it has a cellular
structure, not entirely unlike another cellular structure of a fluid
(but seemingly a solid) which we know very well.

Jorn has had his for 40 years without problems. I can see them lasting a
whole heap longer than that. Once you get beyond the length of one full
career  (say 50 years), just how much more do you want to say they are
as good as wood.





--
Murray McGregor