I would guess that the main reason for linseed oil not forming a hard surface coating on wood is that it doesn't form a surface coating at all. It soaks in. Ma

I would guess that the main reason for linseed oil not forming a hard surface coating on wood is that it doesn't form a surface coating at all. It soaks in. Maybe if you saturate the wood, let it dry, and then keep adding additional coats, you'd start to get one. But, in a world where varnish exists, I'm not sure why you'd do that unless you were trying to reproduce a period technique or something.