Just one excluder.
 
I used to run Consolidated Double-Queen brood nests when I was pushing the
bees into making section comb honey.  (This two-queen idea was covered by
John A. Hogg in ABJ a few years ago.)
 
In this system you have the usual two brood chambers, but have a queen
laying in EACH ONE.  This allowed me to super with comb honey supers easily
with great results.
 
1.  In spring a nuc is made up (2-3 brood combs, 2 of food) in a brood box
and set above the parent colony with a screen board between and small
entrance provided for upper unit, in back.  Queen is introduced to upper
unit. ( ~ April 15-20, NY)
 
2.  Make sure lower unit has plenty of food or feeder, then an
excluder&super later when needed.  Heat from lower unit will help
development of the upper one.  Some brood can also be raised up from below
to ease congestion.
 
3.  After upper unit's population starts expanding well  (say 7-8 frames of
bees and brood), the screen board is removed.   A full sheet of newspaper
is laid atop the lower brood chamber.  Than an excluder goes over this.
Then the upper brood chamber goes on the excluder, then is pushed forward
enough to supply a 3/8" opening along the top rear of the excluder for an
entrance to the upper colony.  Another sheet of newspaper goes on top of
that, and the excluder, super(s) from the lower colony.
 
You can tack a strip above the rear entrance to keep rain out.
 
Both queens remain and continue laying (ideally) all season, or at least
for a few weeks.  These colonies get really strong and can get quite
"swarmy" in certain seasons when run for comb honey.  But if you can keep
them home they'll really plug out the sections nicely, and the supers will
pile up.  I think it's easier in some ways than the usual Killion comb
honey management.   For extracted honey results could be spectacular,
considering all you're doing is adding a $6-10 queen.
 
It's quite a sight to see -- this is a real bee-machine;  lots of flight
from front and back at the same time  and bees bubbling out all over.   Got
to keep them supered up well.  They'll make use of every square inch of
those brood chamber combs
 
The lower queen will fill the combs with brood often clear across the hive;
the upper one won't have quite so much room because the bees will want to
store nectar in the outer combs.  This is not a major drawback;  this new
queen will likely be the one going into winter to start up the next season.
Either before or after the main honey flow you just take the excluder out
from between the brood chambers and that's that.  You end up with a high
population for wintering.
 
An advantage to this is that if you have a queen fail in a colony it
doesn't take it out of production, there being a second queen.  Plus you
can split the colony into two afterwards or take away the less
desirable/older queen - whatever.     Instead of a "boughten" queen you
could use your own queen cells to establish the upper colony.  Lots of
potential options.
----------------------------------------------------------------------------
--------------
 Note: Any plan like this should be used experimentally (at first), as its
success is likely to be dependent on timing and local conditions.   -  JWG