Heart

[Paul_H]

I have a building contractor that wants some Douglas Fir posts and beams milled for an outside arboretum(sp).He asked that the beams be heart wood(boxed) so they don't twist or open up.

Does this make sense? I thought that the heart tends to move a little more than a beam that was F.O.H.


But, I've been wrong many times before  

[ohsoloco]

From my understanding, a boxed heart has less of a tendency to twist or bow; however, it does have a greater tendency to check.  

What is his definition of "open up?"  That sounds like checking to me...I've heard of kerfing an unseen face of a timber to isolate checking, but have never tried it myself.  

[Paul_H]

Yes,he meant checking.But I think twisting is his biggest concern.

[ARKANSAWYER]

Paul,
  If the tree was straight and you center the pith in the timber it will stay straignter.  It will how ever check worse.  You can take a skill saw and make a cut in the unseen face and most of the checking will be there.  A FOH timber is more likely to bow but less checking.  If it is an outside project then I bet he  wants the heart wood to help with decay.
ARKANSAWYER

[Mark M]

How deep of a cut do you have to make Arky?

Mark

[ARKANSAWYER]

  I try to get the cut about 1 to 1 1/2 inches deep and start 3 inches from the end and stop about 3 inches from the other end.  That way the check goes to the end and looks better then the saw cut.   This works best on timbers that are square or almost square.  Cutting the groove on a 4x10 on the top of the 10 may not do you much good since it is just 2 inches from the sides to the pith.  But it does not hurt to try.
  
ARKANSAWYER