syrup pan- evaporate after shut down?

[SevenCreeksSap]

Okay I did my first boil with about 60 gal sap, and when I shut down had a little panic attack. Its a 2x8 with 2x2 front pan. I understand shutting the valve between the pans so you dont get mixing back so I did that at first.
I was out of sap in the feed tank, and I have a 2x8 tin sheet that fits right down on the pans for a cover. Got the fire put out but there were still coals so I knocked them down through the grate. I had about 1 inch of sweet in both pans. Then I started worrying the front pan would dry up and I'd have a pan of burnt sugar this morning. So I figured I'd rather have a little mixing and opened the valve to at least keep some sap in both pans. I'm pretty sure it wouldnt all evaporate with no fire.

So, my question is for anyone with 2x2 syrup pan or close. About how deep does the sweet need to be without evaporating after shut down, not adding wood?

The top of my draw off outlet is about 1 1/8 inches above the bottom of the pan. If I keep it there would that be deep enough?

I know eventually I dont want it to mix back but I figured for the first real boil I'd rather reboil to get the gradient back until I figure it out.

[red maples]

you want it fairly deep. I ALWAYS ALWAYS ALWAYS have reserved sap on hand. I always leave at least 15-25 gallons of sap in the feed tank after I shut down.

after the fire is out an evap can hold heat for long time and you can actually evap 5-10 gallons of sap after the fire is out. if you want it to cool quickly open the doors and open the door to your sugarhouse hte bricks will cool off much quicker. When its predicted to be a very cold night as soon as I shut down I close the doors tight to hold the temp higher.

I have stainless 2x2 syrup pans and I like to (depending how long I am boiling) do a vinegar soak every or every other night so I don't get hot spots in the pan which can scotch the syrup but usually don't do that with tin.

But again the key is never run out of sap!!!

[heus]

I flood my 2x6 with the last 10 gal or so of sap. I also drain my preheater after I'm sure its not still hot enough to scorch the inside of the tubes.