First All Grain help.

I am setting up to do my first all grain 5 gallon batch. I have been using Beersmith to develop the recipe and figure out mash water/grain ratio. Currently, with 9.2# of grain, it is calling for me to mash in with 11.12 qts of water. I am mashing with a 10 gallon picnic cooler tun, on my last go around, (partial mash) i had an issue keeping the mash temp due to the deadspace. Any thoughts, or ideas on how to overcome this?

Also, I will be Batch Sparging this time around, any hints or tips?

#1: Preheat the cooler with hot water.

#2: Insulate. Wrap it up in a blanket or towels (or both). This, by itself, got me from losing 4 deg. F over an hour to being able to hold the same temp over 75 minutes.

Ditto to #1. Dump in your strike water about 3-5 degrees over what beer smith says. Close the lid and let it sit for 10-20 min to preheat. Then mash in.

Mash in quick, stir well and seal it up. I usually give it a stir 1-2 time during the mash. I find I get a temp gradient during the mash.

Towels, blankets or insulation around the tun like reflectix helps too.

Def going to be insulating this time around. I think a big mistake I made the last time was to preheat the tun, then dump the water, and put the grain in, which I think is what helped kill the mash efficiency.

I agree about pre heating the mash tun. That's the first thing to do. I simply heat my strike water a few degrees hotter, fill the mash tun, and then let it sit until the strike water reaches the desired dough in temperature.

One thing I noticed is your water to grist ratio is a little low, only 1.2 quarts per pound of grain. You can adjust this in beersmith if desired. The default in beersmith is 1.25 quarts per pound. A typical ratio is usally between 1.25 and 2 quarts per pound.
On my system, I prefer a slightly thinner mash (between 1.5 and 2 quarts per pound). This reduces the deadspace and should help maintain mash temperature better.

Also, in beersmith, I check the box to drain the mash tun entirely before sparging which may clean up the mash and sparge volumes you're getting in beersmith.

Thanks for the info, still trying to work through all the nuances of beersmith. Including overcoming the difference between my system and the standards (i.e. 10 gallong cooler, and 7 gallon pot, vs. 10 gallon cooler and 15 gallon pot.