Brower 845 hatching only along edges?

[PostCarbonPioneer]

Hi. I've got an old galvanized Brower incubator, and it's now Day 21.5. These are Black Rock eggs, so sex-linked. I've hatched out 6 chicks of 45 eggs and they've all hatched only along the edges??!!?

I've had trouble with humidity in this incubator in the past, and so have altered it by putting down terrycloth in the very bottom for lockdown (the bottom board was moldy so I've discarded it.) I also put terry strips around the inside edge on top of the screen and worked out a tube system that can be filled from outside to soak the strip. I've managed to keep the humidity between 65-70% for lockdown.

But it seems that the only eggs hatching are those that were slightly touching the terrycloth strips. The center eggs are just sitting there and I see no pips. Eggs were turned regularly by hand, 3x daily, and rotated around the incubator so no egg was always in the same spot during the 2.5 weeks prior.

All 6 eggs so far have been roosters too, frustrating!

Anyone have this center eggs no hatch problem before? It just seems weird.

PCP

 

[BullChick]

I don’t know if you ever found any answers.

Despite rotating the eggs, maybe it’s not enough in your incubator.
First be sure your thermometer and hydrometer are calibrated.
Add heat sinks to keep the temperature steady throughout the Incubator.
Lastly, if you are turning by hand, be sure the rooom isn’t too chilly.