I am doing some solid kitchen doors (no frame). When the boards was dried after resawing there was one end check, sadly a bit longer than I can afford. As I don't have any more similar boards, I tried to penetrate glue in the check (I dilute the glue with a thad of water to decrease viscosity) and apply heavy pressure with clamps for a couple of days.
I have done this a couple of times over the years and so far the cracks have been healed and stayed that way - but I am always worried thath the check will open again....
Has anybody a better process or recommend another glue?