On 04 Dec 96  22:44:02 Roy McNeill typed to Bob Lawrence ....

Hi Roy

 > They vary from dead straight through simple curves to zigzags. A
 > depressing little paragraph in a "Furniture Making" book tells me
 > that proper drying out (60% water to <20% ) can take up to a year.
 > Bloody hell.

 The REAL figures are 1 year for every inch of thickness. I.E a 4x2 will
 take 2 years to dry out _properly_!  Using them at less than 20%
 moisture figure (used for kiln dried) will result in some further
 shrinkage after they are in situ which will leave noticable gaps.
 For a good finish you need them _fully_ dried.

 The above figures are for Tasmanian hardwood so I figure they would
 apply for most hardwoods.

For air drying, the timber needs to be stacked level and straight, with
at least a 1" gap beteween each board and each layer seperated by 1"
thick seperators.  If the seperators are laced about a foot apart and
the stack is of sufficient size, the weight of the timber itself will
reduce the warping and twisting to a minimum.

I found a rule of thumb figure was to get 30% more timber than required
and you will wnd up with enough straight stuff for the job.  TI was told
this figure by an old timer, and used it to purchase ALL the timber for
the house when green.  I racked and dried all the timber I required as
dressed timber such as barge & facia boards, door frames, mantel piece,
exterior wall cladding and also all the timber for the window frames
(Lounge windows were floor to ceiling).

The old guys estimate worked out to be pretty well spot on, with the
warped stuff being used as noggins etc.

I dressed the lot after after about 2.5 years and had NO movement or
gaps at all.  Dressed kiln dried was complete loss for anything except
the rafters and purlon for the 6 sqare carport.

I know that 2 years seems a lonf time but it is woth the wait if you are
doing something like laminated timber bench tops.

The only timber I bought already air dried was for the staircase I built
in a later house and some 3x2's that were Blue Gum railway sleeper
offcuts.  (The Blue Gum HAD to be drilled just to get a nail to go in)
:-)

Best of luck ;-)

Niels

* OLR 5.1 *  Cut your own firewood and it'll warm you twice.

--- FMail/386 0.98