ah-ha not true with regards to home made stands and hoods. its where the good old PVA glue comes in very very handy. three coats - acts like a varnish but creating a plastic like water tight seal. I suppose for the home made it all comes down to the skills and knowledge at hand. a master craftsman will produce something far superior to that of a jewel stand.
sadly though, im not a master craftsman and so my first attempt hood is functional, but alas, the design of a replacement is underway and it will be built in my fathers workshop with the care and skill to make it a piece to envy.