The caveat is that wood glue is stronger than wood if used correctly. Wood glue works best gluing grain to grain. It’s easy to split wood along the grain because the natural bond between the fibers is not that strong and it’s that bond that the wood glue is great at replicating. In your example the wood glue is being tested against the strength of the fibers rather than the bond between them
potent01 t1_iuar6bn wrote
Reply to comment by Sh36fjk374fjc in Is no more nails glue acceptable for attaching wood together for shelving? by ThatCraftyDragon
The caveat is that wood glue is stronger than wood if used correctly. Wood glue works best gluing grain to grain. It’s easy to split wood along the grain because the natural bond between the fibers is not that strong and it’s that bond that the wood glue is great at replicating. In your example the wood glue is being tested against the strength of the fibers rather than the bond between them