Wood Drying

[gordon stelter]

Would there be anything wrong with building a sealed
room with a dehumidifier running in it to dry lumber?
     Thump

--- Ron Overs <sec@overspianos.com.au> wrote:
> >Terry,
> >
> >Your most immediate danger is too rapid drying
> through the end grain.  THe
> >dimensioinal change from differential drying
> through the end can create
> >checking that will make large sections of wood
> unusable.  Don't waste a
> >second getting some form of moisture-impervious
> sealant into the end of
> >every piece.  Melted parafin wax works best, IMHO.
> 
> Or, if you have any wood glue (out of date Titebond
> or rubbish PVA)
> lying about, that works very well also. When
> sourcing local logs, we
> specify that the log is end-sealed as soon as it is
> cut.
> 
> Your idea of breaking the log down into 1/2" boards
> is a good one.
> Such boards will be ready to use in one year with
> just air drying
> (ie. for the panel, rib stock will take at least two
> years, unless
> you plan to make laminated ribs out of the 1/2"
> boards). When we
> break down a log for sound board material, after the
> large boards (2"
> thick) have been cut out, we break down all the
> small triangular
> flitchs into 1/2" wide boards, so as to obtain the
> maximum of useable
> spruce from the log (you will need a resaw with a
> tilting table for
> this purpose). The danger with drying is moisture
> gradients.
> Therefore, the thinner cut boards will tend to have
> less of a
> gradient problem, but they will be more prone to
> warpage. As soon as
> you have cut your boards, they should be stacked
> with spacing sticks
> (of say 25 mm by 25 mm section) between each layer
> of boards, spaced
> at about 300 mm (1') for boards 1" or thicker. I
> would recommend that
> the spacing sticks be set somewhat closer together
> for 1/2" boards to
> reduce warpage. The entire stack should be covered
> with some kind of
> roofing material and weighted on top (house bricks
> will do) to ensure
> that the upper boards in the stack are held down to
> prevent them from
> warping. Don't make the stack too high or the
> overall weight will
> cause the lower boards to sustain crush damage
> adjacent to the spacer
> sticks.
> 
> I'll photograph the drying stack I have at the house
> and send you a
> jpeg. Looking at your location Terry (27 degress N,
> - I notice that
> you have another Sydney a few miles east), I would
> recommend that you
> commence the drying process during the winter
> months, since the
> summer heat will be very risky for freshly sawn
> boards. It is the
> initial drying phase during which degrade from
> moisture gradients is
> more likely to occur. Furthermore, quarter cut
> boards will tend to
> lose moisture faster through the edge of the board
> compared to the
> quartered face. This will occur with a quarter cut
> board since the
> medullary rays will be perpendicular to the edge and
> parallel to the
> board face. We seal the edges of quarter cut boards
> as soon as they
> come off the saw. This will greatly reduce the risk
> of stress damage
> at the edge of a quarter cut board during the drying
> process. I have
> noticed a tendency for belly wood to be more prone
> to compression set
> damage adjacent to the board joints. While there may
> be a multitude
> of reasons why this might be so, I have long
> suspected that the
> tendency for quarter cut boards to lose moisture
> faster through the
> edge, particularly during the initial drying phase,
> to be a factor
> here.
> 
> By the way folks, our new sound board conditioning
> box is coming
> along nicely (the new box is big enough to
> accommodate a Bösendorfer
> Imperial board). If anyone is interested I'll be
> taking a photo of
> the assembly prior to fixing the last side of the
> box, so that you
> can view the layout of the air ducting. I'll put in
> on the web site
> and let you know when it is up.
> 
> Best,
> Ron O.
> --
> _______________________
> 
> OVERS PIANOS - SYDNEY
> Grand Piano Manufacturers
> 
> Web: http://overspianos.com.au
> mailto:info@overspianos.com.au
> _______________________


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