This is a touchy subject, judging by all the replys. I have been on both sides, doing work for a so called friend for nothing, and refusing to do the work for little or nothing. The guy is a user as Denny said; folks like that will run you into the ground if you let them. Take care of your grandkids, and your own wants. He can look elsewhere, or maybe already has. Either way, you're better off, you will be sorry if you take that job on.