[Lauri]

3" hole with screen attached on top lets you invert a wide mouth mason jar on the hole, yet slightly cover the edges to keep light rain out, warmth in and those few foragers that want a free lunch on the edges away. Cover it or not, depending on the temps and weather.

No room inside a nuc for feeding, this works for me.
Make sure you punch your holes in the lid, then flip the lid and screw on the bands or they can't reach the feed through the screen if lid is concave.

 

[Lauri]

I use frame feeders in any hive with standard frames, but use mason jar feeders for almost all my mini frame nucs. So that's what I'll comment on here.

Those screened holes in my mating nucs also double as vent holes when they are first made up so I can confine the bees for a while until the cell emerges.

Crack the lid when confined, maybe not this much unless temps are hot, a small shim would do but you get the idea

I use FRP for my inner covers, you can use the cut out plug for a nuc closure if you want.

Ditto for my nuc transport boxes. Cut a 3-4" hole in the lid, screen it so I can top off the bees with a quart of syrup before I send them off, good extra ventilation while they are confined. Use hot melt to attach screen to waxed cardboard.


Here's the difference in take up between a wide mouth lid and a small mouth. All these jars were filled when placed on the table. Larger surface area, a few more access holes in the larger lid.
Anything smaller would likely be a very slow intake.

My mating nucs will usually take up a quart of syrup in one day. I wouldn't want the jar to sit on there for a longer period,exposed to bad weather, getting sour or attracting robbers.