Best log yield?

[Bullheaded]

Was there ever a book or brochure put out about best yield "hints and practices"?

I am relatively new to the circle sawmill and recently "knighted" new sawyer at out local summer fair. The longtime sawyer saw an easy target based on enthusiasm! Anyway, as I cut lumber with my circle mill, I feel like I am wasting opportunity's. I need to mill a dozen 2x8 12 footers out of a nice white spruce that I hauled home yesterday....dead/standing for about a year. If I am careful and use a 3/8 kerf, I think I should get (5) 2x8's and (2) 2x6's out of this butt log which is 14" at the small end of the first log.....butt is 17". Sound reasonable?

Sir Michael of the North

[Jeff]

It really depends on first experience, and second the log and it's quality, and third what you can use or market from the yielded lumber. Actually the order is interchangeable.

Yield means nothing if it can't be utilized in a way that meets your needs, be they material, or financial. No book is going to teach you those things, unless they write one about every log.

[Andries]

Bullheaded, there is a very good series of YouTube videos made by forum member Yellowhammer.
His latest one is about maximizing the yield out of a lower quality Cherry log.
I realize he uses a bandsaw and you're set up with a circle saw, but the principles are similar.
Keep in mind that YH is milling for high-grade woodworking lumber and not framing or construction lumber. That's why you see him getting a rash about bow in a board, as compared to crook. His customers want absolutely flat lumber.
I haven't seen a lay persons popular book on this topic, only technical research and academic/industrial kinds of publications.
YouTube can be your friend.
It all goes back to Jeff's comment:
"Yield means nothing if it can't be utilized in a way that meets your needs, be they material, or financial."

[beenthere]

Jeff summed it up very well. A new decision and result can happen after exposure following every saw cut. 

[barbender]

When I was in grade school, there was a bookseries called "Which Way Books". You'd read along in the story, and come to a spot where you had to make a decision. You turned to a specific page based on your decision, which led to more decisions. All of those decisions contributed to what ending you got. 

Sawing a log is much the same😊

If your cut list only includes wide 2x material, you're going to have more waste than if you can utilize some 1x or narrower 2x off the outside. 

[Magicman]

I realize that I am "bandmill" vs "circle mill" but I have often stated that the opening face is the most important cut that you make on a log.  What you get out of a log depends upon the quality of the log, your cut list, and your log rotation sequence.

The Opening Face

[longtime lurker]

I like to say that there are three basic ways to saw a log; the way that yields the most fibre, the way that yields the most value, and the way that yields what the order book requires today.
Those three options never align, and learning which to prioritise and when is an important part of running a sawmill business.
Sawing for orders gives cash flow and that's what keeps the doors open.
Stealing boards out of logs... forcing them to cut what they don't want to be... to fill an order is wasteful and never profitable because fibre recovery nose dives fast doing it.
Cutting high value boards that you have no orders for won't put food on the table this week.
Cutting high value boards is quite profitable in the long term.
Cutting sizes that don't move to increase fibre recovery results in mountains of undesirable stock.
Cutting stuff that sells fast at a low margin isn't viable unless you're big.

There's no absolute right answer here, it's just that choosing the wrong ones will send you broke.

[thecfarm]

I also feel 2-3-4 sawyers will get different results.

[Bullheaded]

Very interesting and informative answers. I have no intentions of ever sawing for a business. I want to keep it fun. I am enjoying the technical aspect of setting up the saw correctly and overcoming those challenges. Yesterday, I added a cable actuated foot throttle which turned out very well. I really like advancing the carriage at idle when setting to a pencil line. That Wisconsin VF4 is a thirsty little bugger at 2400rpm. Idle rpm at everything except feed and gig back should help a lot. I can make an 8" cut in softwoods at full feed on the Belsaw. Yesterday was very rewarding and netted (7) full 2x8 12 footers for rafters on the mill shed.

[NewYankeeSawmill]

When I was in grade school, there was a bookseries called "Which Way Books". You'd read along in the story, and come to a spot where you had to make a decision. You turned to a specific page based on your decision, which led to more decisions. All of those decisions contributed to what ending you got.

Man, thanks for jogging that brain cell back to life! I used to LOVE those books! Would re-read them over and over to get to a different story. Good stuff.

[barbender]

They were cool books, NYS! They were actually kind of dark, I remember the one I ended up dying alone on an alien planet after running out if oxygen. Kind of a lot for an 8 year old😊

[jpassardi]

Sounds like you're still bearing the scars BB! 

[barbender]

I carry a lot😂

[Ianab]

Adding to what LongtimeLurker has said, on the IT side, a modern mill will be scanning logs and comparing that data to market prices, stock levels, and current orders. 

So sure good 12x2s are worth more than two 6x2s, but if you have a large order of 6x2 to fill This Week, then you can adjust the sawing patterns. Get paid this week vs maybe a little more sometime in the future?

It's that juggling the various factors that keeps sawmilling interesting. On a commercial scale it's success or failure. But even on a hobby level, it's still about getting the best results, even if the weeks payroll doesn't depend on it. No point cutting 2z12s that won't do the job, and fall apart because of some heart check or rot. But you don't that for sure until you open the log up. 

As other have said, be prepared to adjust your plan once you see inside the log. You can load up a log and think "Yeah that will make some sweet 2 x 12". Then you find a defect in the log. OK, maybe two 2 x 4 and a piece of firewood. 

[longtime lurker]

Several years ago I read the results of a national survey into the hardwood sector here in Australia. There were no real surprises... mills running on Mk1 eyeball scanning systems significantly outperformed mills running on any modern scanner for yield. The big guys however had a consideeably cheaper cost of production. As I said... no surprises there at all. When I see a computer that can outperform me I'm going to retire.

Thing with yield is its a deceptive number.... it can mean what you want it to mean depending on what you count in or out.  Does total yield include landscape timbers and stakes? Do we factor in grade to our yield numbers? I tend to have a lower yield percentage than a lot of my peers but my target size on grade yield tends to be high... I've got poor logs and skilled sawyers. But because my log quality is low I struggle to cut some sizes and logs that will cut them get cut for those regardless of orders. 12x2 or heart free 6x6's are a whole lot harder to find than 6x2's for instance.

Log quality is the major factor all other things being equal, it's easy to get good numbers in veneer logs and impossible if you're sawing didgeridoos. But it doesn't mean didgeridoos can't be profitable if you're buying them at the right price. 

One of my things is the amount of time I've invested into finding cost neutral long term markets for crap... stakes and pegs and dunnage mostly.  Having steady demand for 1x1 or 2x1¹/2 at cost of production gives me a lot of options to keep my overall yield up while sawing for orders. So I guess my priority list looks like  hard to get but easy to sell sizes, today's order book sizes, stuff that sells so I carry stock sizes, and my downgrade sizes like stakes and garden sleepers. As we grow larger I depend more and more on holding stock... I try and fill orders from stock and saw to replace the stock. But I am transitioning to being a lumber yard with a sawmill, and being the guy who can fill orders fast is a handy competitive edge in any business.

[YellowHammer]

My friendly advice is forget about yield, concentrate on learning how to make straight, stress free, usable wood.  After that, yield will come. 

 I've never heard any backyard grill master brag about how many hamburgers or ribs he could grill per pound of meet, the bragging rights are in how well they taste! 

If you cut a bunch of warped and twisted boards and have to fight them to build something straight and plumb, what's the point?  Sawing wood isn't like slicing cheese, it's much more like slicing a carrot and how to get the peel to come off straight, instead of curved. 

If you sell lumber, and you probably will at some time, then your reputation as a Sawyer and sales levels are proportional to how well the customer likes your lumber.

If you buy logs to scale, such as Doyle, then all you have to do is beat scale, and you are doing fine.  If you get them for free, who cares what the yield is if half of them turn out nasty, and you eventually throw them into the burn pile, or let them rot because you don't want to use them?

I sawed up some rafters one time, I just whacked em out, I kind of dried them, and slapped them up for a shed roof.  A few months later, they had moved and twisted so much, some had ripped holes in the sheet metal where the roofing screws went in.  What value was that, when I had to then strip the metal off, make new rafters that were sawn right, and repair the whole mess?  I sure didn't care about yield then, I learned a very valuable lesson.

Everyone complains about the low quality of big box store wood, and rightfully so.  Use your sawmill to produce the kind of straight and high quality wood you wish you could buy, and enjoy learning how to make lumber you can be proud of, and not just a big wad of twisted carrot peels.
   

 

[Magicman]

Absolutely. 

I only custom saw but as is well known here, I will not split a pith which could/will produce crooked lumber.  A flitch may make one 1X4 & one 1X6, etc. which could crook but I will always settle for one board per flitch which will remain straight.

Quality always trumps quantity.

[longtime lurker]

I like having a quality product, and I've worked hard to get a reputation for it. But...

My business changed over time. I went from dealing in high grade cabinet and joinery species to dealing in eucalypt hardwoods used for construction purposes. That's about the log resource thats available right, but also about cash flow and customer demand, the regional and domestic economies, exchange rate fluctuations around imported alternatives etc etc etc. Not every household wants or can afford a high end timber kitchen and fancy mouldings, but the verandahs done in strong, extremely durable eucalypt type hardwoods are a staple factor of the northern Australian lifestyle.

So my product line is strong on square posts, bearers, joists, rafters etc as green off saw graded structural products  and decking, flooring and cladding as KD finished articles; and I hit the same cross section x length combinations over and over because that's what the span tables dictate be used.

To use Lynn's example of the flitch( and I completely agree with him) I might shift a thousand feet of 8x1 a year - I don't want 8x1, it doesn't make me money.
8 x 1 ¹/₄ for fascia if I can squeak out a little more thickness is a fascia size and we do shift a bit of it although the majority of houses here today are built with cheap finger jointed pine in that application. Builders like the pine... its easy to install and it's a non critical non structural application per code so they can.

But 4x1 or 6x1 are the two most commonly used feedstock sizes for flooring, decking and cladding and I can sell those by the mile. Today i have around 40mBf of stock piled up here in those 2 sizes and it's still not enough so we'll make more tomorrow or buy some in.

Now I'm not going to split that flitch for a pair of 4's, too much spring. I'm going to take a 6, with an inch by inch either side of it and turn the whole lot into money. I won't make any profit on the 1x1 but I will cover cost... and by keeping my total yield up I keep my average cost of production down.

Yield does matter, that's why the big boys pay so much attention to it. But the number I track is yield that meets grade in sizes that sell . That's the one that matters because it's what determines whether we make money or starve, and I'm skinny enough now

To throw some numbers at it based on a 12' length I'd get, ( based on durability class 1 hardwood, F17 or better structural grade, Standard and Better appearance class)... and these are Australian Dollar numbers so don't translate to USD but the methodology of the thought process does

8x1x12 $54.18 + GST, sometime in the next year when somebody orders some, it just doesn't move from stock and neither I nor any wholesaler wants it
4x1x12 ( two of) ... sold green off saw at wholesale $30.60 
                         ... finished as a pair  of 3⁷/₁₆ x 3/4 decking board which is a standard dimension here... $61.20 + tax. Now maybe I can get those two boards out straight out of those crooked 4x1 and maybe I cant and have to dock them. I don't really want lengths under 8' in my decking packs though, and I have to machine two boards not one so it's more expensive in the drymill.
6 x 1 x 12... sold green off saw at wholesale $24.30
               ... finished as 5 ⁷/₁₆ x 3/4 decking board which is the standard dimension here... $59.40
               And I also get 4 of 5' inch by inch stakes ( unpointed) which will give me a whopping $6.56 but they shift out the door as quick as we can make them. There ain't no profit in it, it's cost recovery only but it does bring the recovery up.

Any which way there you get pretty much the total available fibre recovery from that flitch. But one way doesn't sell, the 4x1 option is better at wholesale which is around cost + 5%, because as a finished product it costs effectively twice as much to machine. The 6x1 option with the added stakes however wins hands down whether you sell it green in a block stack or sell it finished. Throw the stakes out with the edgings though and it is the least viable alternative.

Yield matters because it determines cost of production... the more saleable fibre you get out of a log the lower the unit cost to buy and process it. Downgrade and byproduct are a PITA and none of us like them but the money from them brings the cost of producing the good stuff thats got market demand lower.  Quality of product matters, and I'm not talking about the sale of bent and twisted stuff that should be sent for firewood. But I am ever mindful of something an old farmer I once worked for told me, that there was less profit in selling the 100% perfect banana than in selling the 80% perfect banana because either way sells but one costs too much to produce. One perfect board in my business is never as profitable as an acceptable one, and I have to fight my OCD tendencies about it all the time.

Everyone's numbers are different of course. Every log is different and we all have different species and markets and alla that stuff. But there surely is a reason those big mills track recovery to three decimal places, and it's not because they've got a guy sitting in an office with nothing better to do. It's all about the money.