Log centering techniques

[dogbo2013]

Got it. Thank you for the explanation. That makes good sense. Cant wait to try this!

[YellowHammer]

This is the kind of cherry I get from parallel bark sawing.  These were put on the sales rack yesterday.  Notice how the grain is generally centered and parallel to the face of the boards.  This keeps them flat and more well behaved and gives them a nice, uniform look.  Also, you might notice how there is no sapwood on these boards, which is a benefit from parallel bark sawing, the sapwood borders are even on both sides and ends so edging is easy and not too wasteful.  Looking closely at the board on the left, you can see a very parallel sawn face, basically tracking one growth ring, but on the right was a log with lots of sweep, and you can see that I had to play games with it, basically milling it with the sweep to the side so the stress in the log cause the board to curve, not bow.  It also has a very distinctive look, but results in a very flat board.  

The reality of it, I'll saw any log, any way, to get the flattest, prettiest, widest boards.  I'm not a purist, but more of a free styler.  However, there is a reason behind every cut I take, unless I hit a backstop. :D

 

[longtime lurker]

I'll make a video, but the best analogy I have is peeling a carrot with a carrot peeler.  It doesn't matter how tapered the carrot is, the carrot peeler will only make a cut or peel parallel to the side or face of the carrot being peeled.  So that is parallel carrot peeling, which is the same as parallel bark sawing.  As the carrot is rotated, the peels keep coming off parallel to the surface being peeled, and when done, the remaining part of the carrot is still tapered, but the peels are all parallel to the surface.  

In real life, most times cherry and walnut has some good and bad faces, and so in those cases, to make the technique more practical, I'll parallel bark saw the two best faces, so I don't have to always fiddle with my toe boards in every rotation.  It also helps to be aware of any knots and put them in the non parallel bark sawn boards so they can be edged off later, without losing the value of the better pieces.  It's hard to explain, but pretty easy to do.  

It's all about getting the best, most parallel sapwood and heartwood boards from the best faces, to get the widest, highest grade boards.

That carrot analogy is about the best explanation of taper sawing ever Robert. Really well put.

[Magicman]

Always be very aware of the orientation of the pith check when sawing both Cherry and Walnut and yes, they both always have one, some just more distinct than others. 




Not paying attention to it when opening faces will ruin both your lumber and your day. 

[WV Sawmiller]

Lynn/Robert,

 My biggest challenge comes when I look at a log like you just showed with a distinct heart check telling me "Saw parallel to me so the split is not in every board" and serious conflicting sweep that says saw opposite the normal crack so the board curve face in instead of to the side. Any thoughts and wisdom to share there?

[Magicman]

Every log is an individual unto itself, and every rule has an exception.  :  (Chapter 3, paragraph 7, in Sawmilling 101.)  :P

[YellowHammer]

This is a typical high grade, big money cherry log, big and sweet and well marked. It looks like it has an unworkable heart check but not really. It's really 2 logs in one and needs to be sawn with two patterns, as if it was two logs. If you look closely, you can see a distinct boundary of money heartwood and junk heartwood.  The actual core pith check is an even smaller inner circle between the innermost red lines only and can be seen to have a little shake at the center of the log.   I circled low grade/high grade heartwood boundary in the photo and can be seen in MM picture.  The wood inside the circle isn't all pith, there is some amount of good wood in there. You can clearly see a distinct boundary where the log is badly checked and appears to run to the outside heartwood but in actuality the major check, originating at the much smaller pith ring at the center of the log, stops at the hand drawn circle.  So there are several distinct boundaries in this log and they are the sapwood/high grade heartwood/low grade heartwood/pith.  However, the check that originates deep in the pith looks like it's running out of the low grade heartwood circle but that part of the check outside the circle is really a drying check that is being forced open by the stress of the pith check. There are other drying checks in a radial pattern in the heartwood outside the circle I drew. So the outside of the circle is a different sawing pattern than inside the circle. To reduce bow and induce curve or slip I would saw perpendicular to the check as indicated by the lines and get the good wood, and big boards. They won't have much of a drying crack in the end once the stress is removed and if they do, I would pack saw the ends off later because I cut the log with some trim left on. These big wide boards would be the best on the log. So only after I got all the cuts perpendicular to the check but not crossing the boundary circle would I then rotate the cant and get narrower and bowed boards parallel to the pith check but still outside the circular boundary.  These will all be excellent quality, high grade and probably clear boards but less so as I get closer to the circle.  However, these narrower ones will have a tendency to bow because they are sawn parallel to the major check.

Once the cant is about the size of the circle, I consider it another log and how I saw it depends on how big it is. If it's only about 6 inches or so wide I'd just saw parallel to the pith, until I get to the pith, and whatever get the boards I could, knowing any of these will be lower quality with some pin knots, bow, and some possible pith checks.  However, this wood inside the circle would be bonus wood, because I've already got the high grade filleted off.

As I said earlier, this is a money log and I'd buy it in an instant.  I don't know if this makes sense but look for the outer log and then the inner log and attack them differently. Also look for the distinctive boundary between pith a check and drying check, even if it looks like it's all the same.  Also look for areas of shake and heartwood discontinuities and saw it up accordingly.
  

[Magicman]

Robert's example above is very accurate but in my instance, an exception.  I am not in the lumber selling market.  I custom saw to the customer's specification, and in this instance he wanted the most and widest boards possible.  Here is a link: Log Setup in Sawmills and Milling  showing me sawing that log.  Also scroll down to Reply#11 and see another 31" Cherry log that I sawed the next day.

The cut list is what is important.  If it is yours you may saw it one way but if it is the customer's cut list, you saw it his way.

[Florida boy]

Ok we have gone over how and when to saw grade vs center . But how do you guys decide when to live edge slab or saw "straight through"? 
 Ive got a few walnut that are 18'long with bit of taper. Im thinking of sawing in half to maximize yeild but i could always just slab the whole log . Diameters start at 22" and go to about 16

Does anyone pull a live edge pith slab from center then cut the top and bottom halves for grade ? 

[doc henderson]

I would cut in half at least.  depends on if it takes a bend, or and abrupt diameter change.  also mostly, what are you or someone you might market to going to use it for.  Most wood workers do not want an 18 foot board.  although if I were building a huge bar and wanted a long dark strip...  what you describe would be fine.  It would be better if you already had each piece you plan to mill, sold or placed in a project.  I mill much of it 7/8th inch and can plane down to 3/4.  If you mill puts deep marks in the saw cut, you might go a full 1 inch to be able to plane down.  What you plan to do with the wood will help you decide how to mill it.

[YellowHammer]

Does anyone pull a live edge pith slab from center then cut the top and bottom halves for grade ?

I generally take my live edge slabs using the same sawing pattern, as the highest quality live edge are taken from the same places as the where the highest quality 4/4 is.  Notice in my drawing that those first cuts go bark to bark.  So I would cut the bark to bark lines in the drawing to 2 3/8" for live edge slabs, and go all the way down to where the pith just starts and shows on only one face of the last live edge board toward the center.  

Then rotate 180 and take live edge slabs down to were the pith crack is just showing in one face of the last live edge piece.  These are the widest possible live edge from the log without a two face pith crack.  

I almost never cut through the direct pith for a live edge slab as it will crack anyway when it dries and also will develop a lot of cup.  

Once I have cut down to the visible pith in both sides of the cant, I rotate 90 and take edged 8/4 or 4/4 from the remaining cant. So I normally get live edge and edged boards from the same log, and remain with the pithy center cant.

Sometimes I will go edge to edge and through saw the entire log, but rarely on cherry or walnut.

[redbeard]

@Florida boy the 22" walnut log your mentioning sounds like you may want too go for live edge slabs.
Here's a idea we do alot with logs that size, we go for glue up packages.
2-1/2" thick slabs will be the yield,
Keep the center slab with pith centered in the 2-1/2" and that will give you the best 90° cambium layer live edge and the other two 2-1/2" slabs are on each side of the pith.
This gives you some nice options for a nice 40"-42" wide glue up table top

 

[Florida boy]

Thanks guys seems like there plenty of ways to skin the cat and each one has a place . 
  Well i cut a walnut last weekend not the bigger one though.
 
It was 17'7" not sure  on the diamater now. I cut it in half lengthwise
Each piece had a little sweep to it so i orented those so that the curve would become crook instead of bow. Made some nice 5/4 10.5" wide stock. 
The pith oli left in a 3.5x3.5 maybe it can be cut down for table legs we will see how it dries

[Walnut Beast]

This is a typical high grade, big money cherry log, big and sweet and well marked. It looks like it has an unworkable heart check but not really. It's really 2 logs in one and needs to be sawn with two patterns, as if it was two logs. If you look closely, you can see a distinct boundary of money heartwood and junk heartwood.  The actual core pith check is an even smaller inner circle between the innermost red lines only and can be seen to have a little shake at the center of the log.   I circled low grade/high grade heartwood boundary in the photo and can be seen in MM picture.  The wood inside the circle isn't all pith, there is some amount of good wood in there. You can clearly see a distinct boundary where the log is badly checked and appears to run to the outside heartwood but in actuality the major check, originating at the much smaller pith ring at the center of the log, stops at the hand drawn circle.  So there are several distinct boundaries in this log and they are the sapwood/high grade heartwood/low grade heartwood/pith.  However, the check that originates deep in the pith looks like it's running out of the low grade heartwood circle but that part of the check outside the circle is really a drying check that is being forced open by the stress of the pith check. There are other drying checks in a radial pattern in the heartwood outside the circle I drew. So the outside of the circle is a different sawing pattern than inside the circle. To reduce bow and induce curve or slip I would saw perpendicular to the check as indicated by the lines and get the good wood, and big boards. They won't have much of a drying crack in the end once the stress is removed and if they do, I would pack saw the ends off later because I cut the log with some trim left on. These big wide boards would be the best on the log. So only after I got all the cuts perpendicular to the check but not crossing the boundary circle would I then rotate the cant and get narrower and bowed boards parallel to the pith check but still outside the circular boundary.  These will all be excellent quality, high grade and probably clear boards but less so as I get closer to the circle.  However, these narrower ones will have a tendency to bow because they are sawn parallel to the major check.

Once the cant is about the size of the circle, I consider it another log and how I saw it depends on how big it is. If it's only about 6 inches or so wide I'd just saw parallel to the pith, until I get to the pith, and whatever get the boards I could, knowing any of these will be lower quality with some pin knots, bow, and some possible pith checks.  However, this wood inside the circle would be bonus wood, because I've already got the high grade filleted off.

As I said earlier, this is a money log and I'd buy it in an instant.  I don't know if this makes sense but look for the outer log and then the inner log and attack them differently. Also look for the distinctive boundary between pith a check and drying check, even if it looks like it's all the same.  Also look for areas of shake and heartwood discontinuities and saw it up accordingly.
 

Some really good older reads by some really good people. Thanks to all you guys that take the time to post thorough examples 

[arky217]

I mill SYP for construction lumber only, such as 2x's and boards for floors, roofs, and board & batten.
I have always milled parallel to the pith and try to enclose the pith within one board, then
cut the pith out of that board to make 2 narrow boards.

Though I understand the concept of milling parallel to the bark,
in my instance, it doesn't seem too practical because my trees nearly always have a huge bell
at the stump end that extends usually about 4 feet up the log.

So, with that being the case, should I continue milling with the pith centered,
or should I level the portion of the log beyond the bell, cut the bell off first, then
cut parallel to the remaining bark ?

[btulloh]

For construction lumber I level the pith like you're doing.  I cut parallel to the bark for grade sawing furniture lumber, mainly in hardwood.  

[Lasershark]

  I have a different kind of mill but the principle you describe with the jack sounds the same as me using my hydraulic toe boards where I lift the small end to the point, hopefully, the center of the pith is parallel to my rails/bed on my mill and I am sawing parallel to the centered pith.

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

[Old Greenhorn]

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

Put my name on that list too! Maybe a beeper would also be helpful on certain days.

[YellowHammer]

As I was looking again at the picture of the money cherry log, it just jumps out that I would mill it as two distinct logs, because of the clearly visible shake.  For such a log, the alignment is really to the inside boundary of the shake, or parallel to the inner shake, as any board sawn that crosses the shake boundary on its board face will be ruined.  So it takes some Kentucky Windage to try to get that alignment.

That log is a great example, because if I was just doing a conventional through sawing technique, many of the boards would cross the shake boundary, in a couple places, and be trash by the time they came out of the kiln.    

[Stephen1]

And, hopefully you remember to lower the toe boards! Honestly, I have been wishing the hydraulic toe boards came with the same flashing lights system as the debarker!  

Put my name on that list too! Maybe a beeper would also be helpful on certain days.

Put my name on the list. I have found I tell myself outloud that the toe boards are up and need to be lowered. :D

[trimguy]

☝️ And that doesn't always help !

[Bruno of NH]

Them dang toe boards  :D
I'm with ya folks 

[Walnut Beast]

As I was looking again at the picture of the money cherry log, it just jumps out that I would mill it as two distinct logs, because of the clearly visible shake.  For such a log, the alignment is really to the inside boundary of the shake, or parallel to the inner shake, as any board sawn that crosses the shake boundary on its board face will be ruined.  So it takes some Kentucky Windage to try to get that alignment.

That log is a great example, because if I was just doing a conventional through sawing technique, many of the boards would cross the shake boundary, in a couple places, and be trash by the time they came out of the kiln.    

Would it only be the bottom boards or would the top ones be affected? 

[YellowHammer]

The 12 o'clock position of the log as it sits has a clear double shake boundary, and it goes down to the 3 and 9 o clock position.  There is an indication of shake at the 6 o'clock position, but it hasn't started to de laminate yet, but I suspect it will.

Generally, most people will mill this log by rotating it 90° so that the major check is now horizontal and parallel to the mill deck, but this would put shake in almost every single wide board, especially on the shaken side.  There would be few usable to the shake boundary, but others would be dead boards off the mill.