Had another 360-degree zipper (but towards the end of the egg, so a perfect spot for zipping), but he didn't make it
Seems like it failed to pip and went straight to zip (but only crushing the shell, not penetrating the membrane - I saw the cracking, but didn't realize it hadn't penetrated). After an hour or so the exposed membrane turned yellow, so I pinched two holes in it, but the chick was silent. I put it back since it might have been resting, but when I came back a few hours later there had been no progress. I removed the shell and the chick was dry (no blood, no yolk). I guess it suffocated in the shell from failing to pip
The weird thing is that humidity was rather high. I'm struggling with my bator temperature-wise, so RH fluctuates quite a lot inside the bator (from spot to spot that is). For lock-down I aimed for 60%, but had to settle for 62-69% (depending on the spot - other parts of the bator, where no eggs were, must have been dry because of insane temperature-variations inside the bator; 8C/14F to begin with, which I managed to get "down" to 4C/7F...).
Once hatching started the humidity went up a lot for some spots - while the temperature on those spots fell - and stayed up (which is why I allowed myself to snatch those two that needed assistance). Part of the eggs remained at 61-65%, but temperature jumping to 38.5-39.5C/101-103F (!). At the same time other eggs had 70-80% (!) (but temperature dropping to 36-36.5C/97-98F) *crapubator*


This was on a very small area as well
When grabbing eggs RH didn't fall below 58% (for the lowest RH - other spots remained above 65% the whole time), and jumped straight back up (I mainly did this when another chick had hatched, and/or when RH had remained way too high).
This leads me to believe that humidity wasn't really the issue here, but temperature. Can that be correct? (too high temperature that is) Can it be that 39C/102F with 65% is actually "dry"?
I have five more eggs in the bator; no cracks/pips, no chirping (I tapped on the shells, but no reaction), but I'll leave them (we're still very early; day 18 starts in 10 min!). I don't have much hope for them though, but I'm still very happy with a 61% hatch-rate (11 (incl 2 assist) out of 18) for a first-time hatch with a horrible, horrible crapubator. If I had been more paranoid (or maybe sticked to not opening the bator???) I might have saved this one, giving 12/18.
The question is; What should I have done different? (besides using a better bator...) Need to learn from this till next time