Hi --
 
Sorry to add to the confusion.  See, foundation is not particularly
attractive to the bees, at least not like drawn comb.  So *sometimes* they
can be slow to go up through and excluder to get to work in a new super.
 
The usual recommendation, if you are going for comb-honey, is to add the
super first without the excluder.  Then go back in a few days, and put the
excluder underneath it, once the bees have begun drawing the combs up there.
 
The only hitch is that you DON'T want to trap the queen in the honey super,
above the excluder.  She *might* be up there.  So you open the hive, remove
the honey-super and put the excluder on the hive, above your three
brood-chambers.
Then just remove each frame from the honey-super and give it a good look,
making sure your queen is not to be seen.  If you do find her, you can
gently brush her off the comb back beneath the excluder.  Then replace the
honey-super, and, if the bees have been working in it (not just loitering,
but actually have begun drawing the combs) they will continue to do so,
despite the excluder.
 
Then all you have to do is keep an eye on that honey super, checking
beneath the lid about once a week or so.  Once the super is 1/2-2/3 full,
lift it off and put a second honey-super of foundation onto the excluder,
and replace the first honey-super *on top*.  By now the bees will be
working full blast through the excluder, so they won't be dissuaded by it
at all.
 
For comb-honey, you should use an excluder, by all means.  If even a few
eggs are laid in your honey-combs, they will end up darkened somewhat, and
you don't want comb honey that has had brood in it before.  By using the
excluder you keep everything pure and clean, and the comb honey will be
exquisite.
 
The honey-barrier idea is often used when going for extracted-honey.  The
principle is, that if there is a layer of honey stored at the upper edge of
the brood-combs, the queen will not venture across it to lay eggs in the
stories above.  In that case you don't need an excluder beneath the
honey-supers (which some say unduly impedes the bees).
 
Some comb-honey producers put a super of drawn (extracting) combs on as the
first super, over an excluder.  The colonies start storing in the combs
early on in the season.  Then the subsequent supers added are all
comb-honey foundation, and each new one added gets set right above the
excluder, the previous supers getting raised up.
 
You probably won't have to worry about a 1st-year colony, as they are in
"growth mode" with a new queen, and not apt to become congested to the
point of swarming like an overwintered colony might.
 
Hope this helps --
 
Regards,
 
JG