[log in to unmask] asked:

> Has anyone ever heard of putting paraffin on the end of top bars?

Sounds like a mess.  I would hesitate to introduce a foreign
substance into the hive on an ongoing basis.  No telling what the
bees might do with it.

As bees will remove wax from Plasticell in late summer, or scavenge
from drawn comb (seemingly at random), I would suspect that the
paraffin would also be "scavenged", and incorporated into wax for
cappings or other purposes.  While this may be harmless, I wonder
how you would isolate the paraffin from the wax when rendering your
wax to recycle it.

I use the plain metal frame rests in brood chambers (sold by Dadant,
and I am sure also sold by others) and I use Strollers 9-frame spacers
in the honey supers. The metal surfaces keep the propolized-frame
problem under control.  Propolis does not glue metal to wood as well
as it glues wood to wood.

There are also the "ridged" frame rests, which reduce the surface
upon which the frame ear rests to a double-thickness of sheet metal.
I do not use these, as one would need to cut a deeper-cut frame rest
"shoulder" in the wood to preserve a consistent bee space.

Another trick I use in dealing with propolis is one that was demonstrated
by Jerry Hayes in one of his entertaining "bee gadgets" presentations.
One takes thin some piano wire, guitar string, or other high-strength wire,
and attaches it to two handles.

The wire is then slowly pulled between two supers to break any propolis
bonds created by the bees.  This eliminates the prying required to break
supers apart, and thereby reduces wear and tear on the corners of supers.

I would not pull too fast, or one might kill bees on top bars with the wire.

I did not jot down the name of the inventor of this technique, but I owe him
a "thank you".