Taper sawing questions

[grweldon]

I was just reading an article on opening the face of a log and I'm confused on the term "taper sawing".  I was under the impression that when sawing softwood, it was important to get the pith of the log equal height from the bed of the mill in order to try to contain it to one board's thickness, usually a 2-by. 

If I'm not mistaken, the article said to make your opening face parallel to the bark OR don't elevate the log at all and make sure the upper face will be at least as wide as the narrowest board you wish to sell.  Then when you rotate the log 180 degrees, the subsequent cuts will automatically be parallel to the bark (or bed as is the case).  I'm thinking that this would give tapered grain and result in lumber that was not as strong as if it would have been more parallel to the pith.

I'm confused and the article is unclear.  Will somebody please shed some light on this situation?

[Chuck White]

I think what you're describing is what is referred to as "flat sawing", as opposed to "quarter sawing".

I've actually never heard the term "taper sawing"!

Interesting!   :P

[Delawhere Jack]

When you have a log with a considerable amount of taper, if you were to level the pith, then the initial boards to come off will be tapered in width over the length of the board, and you would lose a lot of material in edging. You would also lose a lot of material as you remove the taper, ie your first several boards will not be the full length of log.

In a log with taper, the growth rings in the outer layers are more parallel to the bark than to the pith, so taper sawing the outer portion of the log will keep the grain more uniformly centered in the thickness of the boards.

The big question is, how did you get a copy of The Wood-Mizer Way Spring-Summer 2012 edition? ;D

[Ianab]

It is possible to saw a log as you describe.

Instead of levelling the pith and taking off the taper in the outside slab, you level the top of the log, and start taking boards parallel to the bark, on a taper. When you get to the pith, you adjust the angle of the log (or mill) to now match the bottom of the log, and remove the taper by taking a wedge shaped board containing the pith. Then saw the rest of the log to the bottom.

Often your most valuable clear boards are on the outside of the log, and the boards around the pith are the junk. So this can maximise the quality of the boards recovered, and the taper is removed in the low grade wood around the pith.

Works well on a swingblade mill that allows the ends of the rails to be adjusted separately, or can be done using toe boards on a band mill.

Ian

[dgdrls]

This is how Mahoe sawmills describes it   I started saving my pennies for one of these,  ;)

Cut to Taper —"Using the Cut to Taper facility, cut the good wood from the first side of the log then cut a wedged board from the pruning knots or core wood which is a lower grade in the middle. This brings you parallel to the outside of the log, where you can retrieve long lengths of good wood again. This feature is usually associated with much larger mills. The Cut to Taper facility decreases the time spent docking and stacking short boards and increases the quality and value of the sawn board. When you have bought the log, you must get the best out of it to put the money in your pocket. The Cut to Taper facility also makes it faster to load logs onto the sawmill as the final adjustments of lining up the log to the beam can be done at the turn of a handle."

DGDrls



 

[Chuck White]

Hhhhmmmm!

Learn something new every day!  ;)

[beenthere]

Which article on "taper sawing" were you reading?

By Fred Malcom or Hiram Hallock, by chance?

[Ianab]

That picture is a good illustration of the idea. You can see the big defect in the centre of the log. Makes much more sense taking out the taper in there, and recovering the better boards from the outside, parallel to the bark.

The Mahoe is quite clever in that respect. Not only can you adjust the height of the each end individually, you can adjust the horizontal position of the beam independently as well.

Ian

[drobertson]

I think the article in wmz way was discussing taper sawing using the toe rollers to maximize the useable short boards that come with a swelled butt end. I use the toe rollers practically on every log.  The longer the log the more useable lumber you can get.  A 10 foot log will yield some 8 foot boards/ 12 footers 10' boards and so on. I never did worry about the pith parallel thing and bark parallel thing that much.  there has to be give and take with anything that deals with logs and lumber. 

[grweldon]

The big question is, how did you get a copy of The Wood-Mizer Way Spring-Summer 2012 edition? ;D

I was reading a back issue of "Independant Sawmill and Woodlot"... can't remember which one.  If interested, I can look for it and let everyone know...

[GeneWengert-WoodDoc]

I believe I wrote the article.  It applies especially to hardwoods so that you maximize long, high grade pieces, which is the money making part of a sawing.  Sawing time may be extended, but profit will increase greatly.  I always ask if the objective of SAWMILLING is producing lumber or making money.

For softwoods, the strength drops dramatically if there is any slope of grain (SOG).  So, sawing parallel to the bark will reduce SOG.

For softwoods and hardwoods, warp in drying will be less with
"full taper sawing" which means parallel to the bark on all good faces.

[1woodguy]

Taper sawing  always seemed right to me when I thought about it
For me it's better lumber and makes better trim on my router table

[old joe]

Gene.  I just want to welcome you to our forum.  You were one of the first people whose posts I read that helped me learn the little I know.  Thyat was on a different site.  Glad you're here.

Joe

[Ga Mtn Man]

I'm struggling to understand how this works from a practical standpoint. ???  Using this  method, won't every board need to be edged?  Can someone point me to an on-line article on the subject?

[grweldon]

For softwoods, the strength drops dramatically if there is any slope of grain (SOG).  So, sawing parallel to the bark will reduce SOG.

Thank you Gene... although I didn't state such, that is exactly why I was confused.  I didn't realize that slope of grain was not an issue in hardwoods.  I've only milled one hardwood, Pecan, and I was literally ignorant because it was the very first species I had ever milled.  I have much more Pecan to mill and now that I know this, my usable yield will be greater due to the knowledge you have shared.  Thank you so much and welcome to the Forum!

[GeneWengert-WoodDoc]

Not every piece needs to be edged.  After cutting the high grade, then you have a tapered cant.  Square this cant up in the low grade and then any lumber sawn will not need edging.  Note that tapered in width hardwood lumber is legal, but the width is determined 1/3 from the narrow end.

[Okrafarmer]

Not every piece needs to be edged.  After cutting the high grade, then you have a tapered cant.  Square this cant up in the low grade and then any lumber sawn will not need edging.  Note that tapered in width hardwood lumber is legal, but the width is determined 1/3 from the narrow end.

Wheeew. Good to know I won't go to jail!  :D

I have used the taper sawing method on conical shaped walnut and baldcypress logs. Nice results. In my case, I went ahead and cut the cant square in one direction, and tapered it in the other, if that makes sense. So there was no edging to do. When doing that, you do have to remember what you are doing as you turn that log over squaring the cant in one direction, and tapering in the other. If you get distracted, you can forget what you are doing, and end up with some kind of weird rhombus or something.  :-\

Don't ask me how I know that. . . .  :-[

[opticsguy]

I completely do not understand.

Seems you would need to re-level the log for every cut? 

[pineywoods]

I completely do not understand.

Seems you would need to re-level the log for every cut?

Nothing to it IF you have hydraulics  :

[hackberry jake]

Couldn't you just have two opposing sides tapered and two parrellel? You would get straighter grain and if you took them just off th two tapered sides they wouldn't need to be edged.

[Ga Mtn Man]

Couldn't you just have two opposing sides tapered and two parrellel? You would get straighter grain and if you took them just off th two tapered sides they wouldn't need to be edged.

That's exactly what I was thinking.

[beenthere]

I completely do not understand.

Seems you would need to re-level the log for every cut?

Maybe after a board but not every cut, as I see it.

[grweldon]

Couldn't you just have two opposing sides tapered and two parrellel? You would get straighter grain and if you took them just off th two tapered sides they wouldn't need to be edged.

This was exactly what I was thinking.

[grweldon]

I completely do not understand.

Seems you would need to re-level the log for every cut?

Not EVERY cut but you would have to level up the log with toe-boards (or some alternate method) to align the bark parallel to the bed.  You then slice up the log until you get to the desired point.  Turn the log and do the other sides...

[Magicman]

You would use your toe boards on two face openings.  The waste will be a wedge containing the pith.