I do full volume BiaB currently and was entertaining the idea of doing 2 batches parti-gyle style (I'd use my old 40qt kettle for the first boil). I've read various things online with different percentages (60-40, 56-44, etc) but I'm sure they apply to doing traditional mashing with less than a full volume of water.
Has anyone done this? Is it a horrible idea? If you have, what were the approximate percentages?
Before anyone asks, I'm doing this because I want to start keeping a strong and a session on tap at all times, and this seems like an ideal way to do that.