I live in Louisiana and I am contemplating building a solar kiln. I was wondering if you have to use 3/4 plywood on the sides?
Any covering material is O.K. for your kiln. We suggest 3/4 because it provides ridigity and will last a long time. You could use 5/8 CDX.
The total cost of drying the quantity you cite is about $125 per MBF. If someone does it for you, expect to pay about $250 or more, or about $30 per day of kiln drying.
As to coating the ends of your lumber, I suggest a commercial coating such as Anchor Seal. (Did you use 3 coats of spar varnish? Does it adhere to wet lumber well?) Any coating must be applied within hours of cutting the ends if it is to be most effective.
Gene Wengert, forum moderator