true quartersawn yield

[TomFromStLouis]

Anyone put some science to this question? Say I have a 40" sycamore and I quarter it by chainsaw. My thinking is that I would get my best true QS yield by then taking a board or two off each face of the quarter (first true the face and then why not grab a couple nice boards?) and then putting a flat on the outside face and ripping the remainder through and through with the flat against the dogs (somehow). All of this is on a bandsaw mill.

So Doyle says this 8' log should yield about 650bf. If quarterswing, how many total bf would you really expect under this method and how much true QS would you expect to get and how much rift? Let's let the ray flecks define the difference - if you see that nice fleck I call it true QS.

Can you suggest a better way to increase the amount of QS boards?

[Tom]

Instead of sawing the quarter through,  rotate it back and forth onto the two flat sides and each time, cut a board from the underside of the cant.  you will get all quartersawn boards that way.

[MemphisLogger]

I have to respectfully disagree Tom.

I've used both approaches to quarter sawing and found that the QS/rift ratio is about the same determined by the definition according to angle of rings.

Where I do see a difference is in the "balance" of the grain in the resulting boards. When a quarter is sawn through and through, the orientation of the grain in each board is more consistent across its width. When flipped back and forth, each board (after the first few) tends to be more and more "bastard sawn"--the rings start out more perpendicular at the "inside" and become shallower towards the "outside".

This has a large impact on the figure displayed by heavily ray-flecked species such as Oak and Sycamore. It will also have an impact on the stability of panel glue-ups as the tangental/radial shrinkage ratios change with grain orientation.  

Sawing through and through is also less labor intensive and I believe it results in more accurate thickness since you're not counting on the the quarter lying perfectly flat each time you flip it. It's also much easier to keep track of the bookmatching in each quarter--something the discerning woodworker will appreciate.  

[Tom]

I agree with the first sentence of your last paragraph.

I hate to get into these kinds of things from the standpoint of arguing the best way to do something, which tends to turn into the only way to do something.

Let me explain myself before anyone gets hurt feelings. Hopefully I can do so without writing a book.

I have said many times that saw milling is more art than science.  It's human nature, I suppose, for many of us to try to cubbyhole people, jobs, weather and politics.  We find that the "one-shoe-fits- all" philosophy actually fits very few situations.

The science of harvesting quarter-sawn (vertical grain) boards from all logs in one specific way would have to assume that all logs were alike.  The results would have to be repeatable over and over again.  Logs are living things and all are different one from the other. They aren't really round but only some facsimile there-of.  Their grain is not evenly spaced nor is it geometrically identical from one spot to another.  The center of the log isn't necessarily the geometric center.  You can read the content of the log from the opened end only to find that it changes two feet down the log.

It's all right to speak of the science of sawing if you assume it to be just a starting place.  

TomfromStLouis asks for the consideration of the science.  We have to start somewhere.  But, to speak of the way to get the greatest number of a particular shape of object from the division of another shape of object requires that the shapes be known.  Quartering a circular shape that contains concentric circular shapes, and taking a rectangular shape from each of its open faces, alternately, will produce the most rectangular shapes containing lines perpendicular to the wide faces of the rectangles.  That is the science.

Here is where the science doesn't work.

A log isn't perfectly round.  Its grain (imbedded concentric shapes) isn't concentric.  The pith (center of the log) isn't the geometric center.  The problem is three-dimensional rather than two-dimensional and must consider a cylinder, not just a circle.  The shape isn't static and allowances for its movement must be made.  To add the fourth dimension may require that the log be sawed through and through and limit the vertical grain to those boards in the center of the log that just happen to make it.

To obtain boards containing vertical grain requires that a decision be made upon cutting each and every board.  Using the  "science", described above as a model, would indicate that the starting point should be one open face or the other.  Here enters the art.

The number of boards removed from that face would depend on the shape of the log and the direction of the grain within.  In the case of a log that is very oval, the grain in one quarter may define that the majority of that quarter have boards removed from one face before it is turned.  There may be very few boards on the second face that would make vertical grain until the first face was used up.  The remaining second face may only produce vertical grain in very narrow boards.

The art of the problem is the decision to saw from one or the other of the two faces and how many boards to remove before the cant is turned.  It also involves the judgment of economics of time and marketability of the product.

The question asked to put some science to the problem as well as suggesting a better way to increase the amount of QS board feet.  The science was considered and the greatest quantity of board feet, in my opinion, would come from sawing each face alternately.

There is no harm in disagreeing.  I do it all of the time.  There is, and I've said this many times before,  "no one way to saw a log".  There may not even be a "best" way to saw a log, at least not a repeatable one.  This profession is an art not much different than if the sawyer were given a brush and pallet.  To produce the required products from a tree, the sawyer must understand its design and the end product.  

To approach a log as if it were a static shape from which other shapes will be removed is treating a living thing as if it were a piece of plastic.

In this situation the science requires a perfect geometrical shape.  If we have no perfect geometrical shape, then we have an art.  If it is an art then the object is the creation of the end product; not a repeatable procedure but rather a method containing choices.

There is, perhaps, no right or wrong, nor better or worse but rather a direction (suggestion)

[GHRoberts]

Tom ---

I believe that starting with a round log that is quartered, as you flip the log from face to face the first board grain is 90 degrees (quarter sawn) and the last is 45 degrees (rift sawn).

Some people consider 90 degrees to 45 degrees to be quarter sawn. The remained is considered flat sawn.

Other people consider 90 degrees to 60 degrees to be quarter sawn and 60 degrees to 45 degrees to be rift sawn.

[Tom]

[Brian_Bailey]

Tom,

Did you take into consideration the conical congruence of the annual rings before the radial plane was severed from the tangential one to achieve full quartersawn  :P ?

[MemphisLogger]

GHRoberts,

I think you picked out the difference between apples and oranges.

I appreciate that, as I am a picky woodworker  ;D :D

[MemphisLogger]

Tom,

You wrote,

"There is, and I've said this many times before,  "no one way to saw a log".  There may not even be a "best" way to saw a log, at least not a repeatable one.  This profession is an art not much different than if the sawyer were given a brush and pallet.  To produce the required products from a tree, the sawyer must understand its design and the end product."

I couldn't agree with this more. The only thing about sawing logs that I've found consistent is that they are heavy.  :D

But on to the debate . . .

When I first started sawing, I used the flip-back-and-forth method exclusively because A) It was in the Woodmizer materials, B) It was what other sawers I knew did, and C) The thought of clamping the point of a pie to my uprights didn't occur to me.

I would carefully study each quarter as I sawed it to get the most vertical grain. Sometimes I would take 2 or more off a face before flipping if that's the way the rings read. I was thrilled by the wide highly figured boards and I didn't mind that I had to saw "plump" (Thanks for the new word Ron) to take into account the cant spring that seemed to materialize with each flip.

I was so excited to get those boards into my shop when they got back from the kiln but upon standing them up along the walls of my shop, my joy turned to frustration. It took hours to figure out where bookmatching pieces occured in boards of different widths and when I did figure it out, I found that I often had to waste several inches to get to that magical line of bookmatch symmetry.

Then I discovered the through-and-through method of QS and the resulting ease of matching figure. IT IS more wasteful, but the resulting lumber is much easier to work with from a design standpoint. I've printed some diagrams and demonstrated both methods for my woodworker clients and all of them have opted for the thorough-and-through.

You're absolutely right that there is no "best way" but my way works for me, for my reasons and I will always be sure to share what I've learned with others.

     
          

[MemphisLogger]

Tomfrom St.Louis,

What the end market for that Sycamore?

If it's for drawers, I just did a bunch last year that I sawed 5/8" and he strapped them up with stickers and airdried it in his barn/shop in a little over 4 months. It all came out nice and straight and made 1/2" no problem.


  

[Tom]

I don't use the method I described either and wouldn't have mentioned it but for the "most quartersawed" comment".  The only other "better" way is to cut each board as a piece of the pie and I've never been able to figure out how to do that.

Woodmizer didn't use this method when I started either. I learned their modified quarter sawing method which I have described somewhere on this forum.  It works too.

That's good that you have found a procedure that provides a good product for you.  You should tell everybody.  That's how folks learn.  Keep it a secret and that's what it'll be.

[TomFromStLouis]

It is this very disagreement which has suggested to me my modified method: take a board from each flat side of the quarter (as Tom would do), then through and through the remainder. Reason I suggest it is because the first two boards are clearly true quartersawn and will be large and nice in every way. If you kept flipping from here you would end up with zero more true QS. Given ideal geometry, and these sycamores are pretty darn regular, it seems that the through and through next will give a  least two or three more ideal boards. If absolute QS is my top priority (and with sycamore nobody seems to want less), I cannot think of a better way short of taking a board out of the center of each shrinking wedge shape.

Hey, does that work?

And yes Scott, these are drawer stock - he has us sawing 3/4", a little more on ones >12" wide.

Tom - your drawing shows me two very nice wide QS boards, and then maybe only two more that I can sell as QS. The other 6 just don't qualify to my eye and that is why I am trying to find a better way. Now draw us one through and through after taking those first two boards. Since bookmatching is not important here, bet we get better QS yield.

[MemphisLogger]

Tom(fromSt.Louis),

I do something sometimes on logs that are right at 32" that looks something like this:



It would give you the same result doing it the way you're thinking.

The only thing I'd be concerned about is how much those corner-quarters are going to bow being that they're on the outsides of the log.
  

[TomFromStLouis]

Nice drawing Scott. How do you guys do that?!

I think that is pretty much what I am after - too bad most of my material is too big for the mill as is.

I appreciate y'alls input - I don't know about bowing on the saw and stuff like that since I have no experience running a bandmill myself. I am just trying to help a newbie give me what I want.

Any ideas on how to sell the rift and even flat sawn sycamore sitting around from our first attempts?

[MemphisLogger]

I don't know of many uses for flatsawn Sycamore and it's really hard to keep it flat.

The rift should be good for drawer sides or interior furniture parts.

[Stanisas]

There is another way to get 100% QS--radially sawing.  The product is not boards but long wedge shaped pieces. We do this to get blanks for musical instruments from curly maple.  The simple, primitive way we do it is to quarter the log and then keep cutting each quarter in half--you end up with long wedge shaped pieces.  We do this with a chain saw with a verticle milling attachment or free hand.

[Tom]

Tom
If you look at the horizontal  boards in Urban sawyers diagram you will notice that they are intact from one side of the log to the other.  What that does is allow the internal stresses on either side of the pith to counter act each other and the board remains straight.

If you were to split that board down the middle, you  would experience side bend (crook) in each piece.  A rule of thumb is to remember that boards will tend to bend toward the bark. Now, that's just a saying to make you think before you make your cut and not a rule to make you avoid making the cut.  

Crook is a standard hazard of quarter-sawing  the same as Bow and cup are hazards of flat sawing.  they may not even show up until after the wood is dried.  They may not show up at all.  But, the risk is there.

If your rift sawn wood is thick enough you might market it as legs.  When used as table legs, rift sawn produces the same grain pattern on all four sides of the leg.  It is also favored by some who want stability but don't want the medullary rays to show on the surface.

Flat sawn Sycamore isn't prized by any of the woodworkers I know.  It is pretty because of its color but its grain pattern is rather plain.  You would probably be best off marketing its color. The creamy color with pink overtones will sell.

Sycamore is enjoyed by bowl turners because of its locked grain.  That may be a market.  Your boards could be used for turners to glue up bowl stock.  There is a market for small items like pen and pencil sets, carved spoons and items of that nature.  I have one customer who uses Sycamore in musical instruments.  It is also used for pallets, flooring, small boxes, butcher blocks as well as cross ties and fuel.

You may find one of those a markets.

[MemphisLogger]

TomFromStLouis,

That diagram I posted above is part of a PDF I made up on that method. In the document it tells you to saw the pith outta them wide boards after the log is done.

If you want a copy, send me an email with your email  ;)    

[MemphisLogger]

Tom's right about the legs--if you pull boards off each face of the quarter, you can leave that outside corner as a 4x4 or 3x3 and stash it away in your legs/turning blanks bin.

[Larry]

Ok guys this shot of white oak end grain shows quarter sawn by the technical definition.



By Tom in St Louie's definition it is not quarter sawn because it won't show any fleck.

Let's let the ray flecks define the difference - if you see that nice fleck I call it true QS.  

Rays are not parallel to the board surface for the fleck to show.

I have found I can get the most fleck using a method similar to Scott's but sure can't saw 6 boards with fleck.  Think that is where the art comes in.  Sure wish I could do a lot better in the art department as good fleck seems to boost the price a bunch.

[Bro. Noble]

The Arkansawyer was showing me how to predict the quality of the 'flame' in white logs so you would know if they were worth the extra effort to Q-saw.  I believe he learned how from Electric Al.  This would be a good time for one of them (or someone else in the know) to share their knowledge.

[TomFromStLouis]

Tom ---

I believe that starting with a round log that is quartered, as you flip the log from face to face the first board grain is 90 degrees (quarter sawn) and the last is 45 degrees (rift sawn).

Some people consider 90 degrees to 45 degrees to be quarter sawn. The remained is considered flat sawn.

Other people consider 90 degrees to 60 degrees to be quarter sawn and 60 degrees to 45 degrees to be rift sawn.

This is curious geometry. You would think that if 15 degrees one way of 45 degrees is okay for rift (i.e. 60 degrees), then 15 degrees the other side would work too (why not 30 degrees?) So much for technical definitions. If the buyer needs to see fleck to pay more, that's my definition too.

[ARKANSAWYER]

ANY QUESTIONS?
ARKANSAWYER

[Steve]

I got to this late as I was working away and haven't been near the computer.
I have a MD and quartersaw, the way Tom does, all the logs I saw.
It isn't perfect but does an acceptable job. Most grading rules allow up to 45º from perfect quartersawn although my luthier customers are more comfortable with less.
The curl or figure in Koa shows up much more when quartersawn and since it sells for twice the price it its well worth the effort..

[GHRoberts]

Tom ---

You are correct.

90-60 degrees is quarter sawn.
60-30 is rift sawn
30-0  is flat sawn

(I was looking at the quarter sawn picture where all the lumber is 90-45.)