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You could also use MDF 3/4 thick sealing all exposed areas, the whole thing, with a good furniture past wax most use Johnson's Past wax. MDF tends to stay flat unless it gets wet then it just explodes to say the least. The one I have is what I had on hand but I'm not happy with it and will go the MDF route as soon as possible.
Wisdom: Where experience and knowledge combine and become one.
"We are all one decision away from Stupid!!"
"How often we sacrifice the permanent plans of God on the altar of immediate solutions"
I have a very good memory, just short is all.