Q: I have heard that vacuum drying produces whiter wood (especially hard maple) than any other drying process. Is this true?
A: There is truth to your statement, but the correct answer is "sometimes." If the logs or lumber have been mishandled before drying, then the color will be equally bad in a vacuum system, dehumidification system, or steam system. Likewise, if a drying system, vacuum or conventional, isn't run correctly, the color will be bad.
However, in a system with good lumber and with excellent operating procedures, the lumber will be equally white. But overall, a vacuum system will have a higher chance of whiter lumber due to the fast drying. It is also my experience that most vacuum systems are run very well, but that many conventional systems leave something to be desired.
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