Last year I had a hive in two deeps which the bees had stuck together.
In late summer, I told myself I would use a trick I had read about - use
piano wire to separate the burr/bridge comb.
   Well - I never did.
   Sunday - we finally had weather warm and dry enough to get out to
reverse the (now three deeps) colony and figuring that the bees were mostly
in the top, I thought I'd just gently lift and turn the deeps to separate
them.
   Long Story Shortened: NEVER have I killed so many bees and brood!  The
top box came off ok, full of bees but light on stores left a clump of mixed
honey and brood which had formed between the boxes.  Cleaned that up and
confidently attacked the bottom 2 deeps - it's Spring right? the bees will
all be up in the top - right?  Wrong - most were down at the Junction
between the two boxes where at least six frames were joined by comb
containing brood and a couple more frames held reddish honey and some
pollen.
   Again, I "gently" twisted the boxes apart - but - fast or slow -
crushing bees is crushing bees.  I hope I didn't kill the queen -from her
laying pattern - spotty, lots of early drones - she needs to be replaced -
yet she brought the hive through the winter with lots of bees.  I scraped
hundreds of brood in all stages from the Pierco frame (I blame my box brand
mixing for the original problem, BTW) tops and bottoms and the one good
thing I saw was no mites on any of them.
   Bottom board was loaded with black "stuff" mixed with wax scales to the
point that the colony only had a very small entrance and slugs had found
their way to the stuff and apparently liked it cause they stayed.
   Anyway - learn from my mistakes - Keep the burr comb under control from
the get go.  The bees will tell you right away if your boxes have too
much "bee-space" by building lots of comb - fix the boxes right away!  If I
had been able to quickly check this hive in late winter I would have known
it was a hive I could split.  Well, this BeeHaver keeps learning - but -
the poor bees!