I have often found myself with nothing but foundation to put on hives.  If
you put  the excluder on right away, the bees are reluctant to go through
it.  If you leave it out they will usually move up and start drawing the
foundation.  once they have started drawing,  then the excluder can be added
and the bees will continue to draw the comb.  However when using only one
brood chamber, the excluder must be added as soon as the bees have started
shaping cells.  If they get them to half depth, the queen sometimes moves up
to lay in them.
 
 Frank Humphrey
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