I have 1 very strong hive that will need to be split at least in half soon and 1 small hive. The small hive (= 5 frame nuc) has been growing slow this spring. If I moved some bees from my strong hive to the small one do I have to keep them closed up for 24 hrs before blending them with newspaper or can I move them and use the paper as a blocker? What are the chances that the blending will work and there will not be fighting?
Just switch stands during the day and let the foragers from the strong hive return to the weak hive. Very easy, no fighting.
blending (as you call it) can work if the weather is cool and the worker bee's activity is slow enough. when I do this (which is fairly rare and only in cool weather) I add the frame at the outside edge of the box which allows the added bees to slowly moved to the center. moving live bees to another hives is a process highly subject to hazards so it is not something I normally suggest that a new bee keeper should attempt. certain scents (wintergreen I think is one???) added to syrup can mask the difference in smell and allow you to 'dump' live bees right into an existing hive. most time if I need to boost I do so by moving a frame of sealed brood after shaking off the clinging brood bees. this takes a bit more time but the hazards are minimal and the results almost certain. if taken from a very robust hive the cost to the robust hive is almost unnoticeable.