I asked Eva Holiman (the boardlady.com) about safe vacuum values to dry boards.
It seems to depend alot on the construction and how old the board is.
Older Mistrals are only safe to about 6 inHG.
Newer Starboards (Technora construction) can handle almost 12 inHG.
Most modern Cobra Sandwich construction (Technora/Wood/Dram) can take 10 inHg safely.
So, the suggestion is start at 6 inHG (152.4 torr....20.318 Kilopascal) and if you hear the water gurgling, don't increase it more until the gurgle stops.
Add a little more vacuum and if it gurgles some more, leave the vacuum at that level until the gurgling stops.
When you get to about 8-10 in HG with no gurgles, your board is as dry inside as vacuum is going to make it.
Keep a close look at any "soft spots" on the deck and bottom as if you go too high they may "cave in".
Hope this helps, and Thanks again Eva!
Last edited by Roger; 16th August 2008 at 11:28 AM.