2nd runnings beer

This coming weekend a buddy and me wil be brewing side by side brews. He is brewing more or less a belgian strong and i'm doing an imperial porter. Both should weigh in somewhere close to 1.10. Both beers will be 3 gal batches. Our plan is to no sparge our beers and collect first runnings for our individual boils, then combine the 2nd runnings from each and put together to make a belgian/frankenbrew/porter of sorts. Almost partigyle just with two sets of 2nd runnings, so i assume our gravity should be up there. Any clue how big this 2nd beer is going to be?

I have no idea. But how do you get second runnings from a no-sparge mash?

I guess he meant they will just use first runnings with no sparge for their individual beers and then batch sparge once and use that to make the frankenbeer. That's how I understood it. I have no clue what the OG will be. I only take gravity readings after I boil, so I'm not much help on this topic. I just wanted to say I like the idea and it's very clever. Good thinking! I might steal that idea from you and do that in the near future!

What mike said. Sorry very confusing explanation. Guess we'll wing it. I'll report back after the weekend.