"Premature failure" when compared with what? For index and test purposes, not an impossible joint to break at some weight with a bucket of water.
I'll bet that he left his 20,000lb shearing press at school.
Tom, when you make the glue joint,
1. Make certain that the surfaces are all covered = no air spaces inside that are surrounded by glue.
2. When you clamp(?) them together, that has to be the same each time.
3. The thickness of the glue layer between the two boards needs to be the same each time.