I got a friend that want's me to make a wooden head piece for his parents grave out of a 24x18x3" Hawaiian Milo slab. Instead of setting on a slab on cement like a headstone he plans to hang it from frame like a sign so he can easily take it off to maintain the finish. I do some CNC work and know little about finishes but even less about outdoor finishes. Paint is not an option and he is not a woodworker so I want to set him up with a finish than isn't too had for him to maintain but looks beautiful and hope fully protects the Milo color which tends to turn gray in the sun.
I don't think