Quarter-Sawing Technique on a Large Mill
Sawmillers discuss how to go about quarter-sawing logs on a large mill. August 30, 2007
Question
Does anyone know of the best way to quartersaw oak logs on a commercial mill? (Best being highest yield of quartersawn and rift versus time.) There are several entries in the archives about doing this on the smaller mills, but none on larger mills that I can find. The mill would be a commercial band headsaw, with secondary "run-around" bandsaw for breaking down the cants. Logs would be about 18" and larger in diameter.
Forum Resposes
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
Quarter the log and then saw from the face of each quartered piece, alternating from one face to the other.
From the original questioner:
Okay, Doc! I assume that the alternate faces would be cut on the secondary bandsaw. It seems to me that after taking a board off the first face, there would be problems indexing the second face because the first face would not be running on the bed; it would be in the air. Or would the hold-ins be able to accommodate the irregular shape of the outside of the log, holding the second face to the fence?
The only commercial mill that I've seen in operation quartered the log, then dogged the point of the quarter in the air, and sawed the remainder side-to-side, flipping 180D once, I think.
From Professor Gene Wengert, forum technical advisor:
With the "merry-go-round," you have to turn the quarter log around, end for end.
From contributor E:
If you put the face of the quartered log on the bed of the saw and saw the thickness you want from the bed up, you don't need to end for end the log. You also can square the log before you quarter it, then each quarter has four faces. Just saw the two faces that will give you quarter sawn boards.
From Professor Gene Wengert, forum technical advisor:
You can find a saw like contributor E mentions supplied by Baker, and there may be other suppliers too. Contributor E is correct on squaring the log first, but you will lose a lot of yield with that technique of squaring the log, even if you get a flatsawn piece of lumber from the outside. Also, the best part of a q-sawn piece is the outer section, and using his technique, you remove that outer section, so the overall grade of the q-sawn pieces will be lower.
From contributor K:
I am probably one of the smallest operators here, so I don't qualify to be advising a large mill. I wonder if your question should have been worded something like, "What is the smallest diameter that is feasible to QS?" I think for my small mill, it would be somewhere over 30". I am doubtful that it would be worthwhile on larger mills in smaller diameters as well.
From the original questioner:
Hey Doc, how in the world do you turn the log end for end on the merry-go-round? Seems a very cumbersome task to me. Thanks.
From Professor Gene Wengert, forum technical advisor:
The cant exits the saw, is slowly conveyed with the conveyor making a 180 turn, and then is fed back to the infeed and moved into position sideways. Second option is to feed it onto a table that is rotating and pull it off the table after 180 rotation. This works best with shorter material.
From contributor T:
I quartered a 20" box elder today because I had to in order to fill an order. My flame box elder is prolifically red, but does not look much different quartered than flat sawn. The rings look different, yes, but the rings on box elder are wide anyway and it takes close inspection to notice for a novice. The order was for a guitar maker who wanted it as stable as he could get it. I can tell you, quartersawing a 20" fairly crooked log does not leave much. He wanted it bad. I priced it accordingly.
