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Best time to cut Douglas fir

Started by sawbuckacres, December 12, 2009, 05:30:14 PM

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sawbuckacres

Interesting !  So, the thickness of the sap layer is mostly a function of the tree's health, than of age, as I have been told.  You know how difficult it can be to find store-bought lumber that will remain straight if it is stored long - I always thought that was because much of today's commercial lumber was cut from young trees that were primarily sapwood.

I'll have to do some experimentation this summer when I fire up the mill.

SwampDonkey

Quote from: sawbuckacres on December 16, 2009, 05:53:01 PM
So, the thickness of the sap layer is mostly a function of the tree's health, than of age.

Age and health aren't exclusive, at least not over the long haul. Tree diameter, on the other hand, does not correlate well to it's age. Although, I must say that a 40 inch sugar maple up here, is very old. But, a 40 inch maple could be the same age as an 18" one. You can cut a large maple with less than 1/3rd heart, the next one similar in size could be 2/3rds. Heart in sugar maple is not desirable. Yellow birch on the other hand, makes no difference to veneer buyers, it's more stable. Generally, as a tree ages you would expect a greater proportion of heart wood in relation to sapwood. The system becomes less efficient over time like anything that grows old. ;)  Some tree species are just not as efficient in using carbohydrates as others. It's as much genetics as it is health. Take butternut, the sapwood is only as much as an inch wide. It is not a long lived tree, similar to aspen. Maybe 80 -90 years or so.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

WDH

Rocky, I am not insulted as I have licked some wood for wood ID purposes.  Us Georgia boys have a few other talents as well, but since this is not the "Restricted Board" I will refrain from other comment  :).
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Tom

QuoteThe system becomes less efficient over time like anything that grows old. 
ouch!! That hurt.  :D :D :D

SwampDonkey

Didn't plan it to.   :(   :-\


:D :D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

DouginUtah


It is usually a distinct transition from sapwood to heartwood. We see this as a distinct change of color. What is the reason for the very different coloring and why is it so abrupt?

-Doug
When you hang around with good people, good things happen. -Darrell Waltrip

There is no need to say 'unleaded regular gas'. It's all unleaded. Just say 'regular gas'. It's not the 70s anymore. (At least that's what my wife tells me.)

---

SwampDonkey

There is sometimes an intermediate zone between sap and heart. But the intermediate zone, still containing live cells, takes on the color of the heart. The coloring is caused by deposits of extractives, extraneous materials, and infiltrations. And in hardwood, accelerated tyloses formation in the pores. In pine, hemlock, spruce and aspen there is no easily distinguished heart/sap line, yet there is heartwood, because the wood is dead there. Stored substances like carbohydrates in parenchyma cells, located deeper in the sapwood, may exceed the tree's requirements. The substances become polymerized with residual oxygen in the parenchyma cells. Those cells lose efficiency, there is less oxygen, they form extractives. The extractives become lethal to the surrounding cells, respiration ceases, then they die. So, dead heart wood is a barrier to anything coming in from live parenchyma. Basically, stuff accumulates at the heart wood boundary and becomes lethal to living cells. They then become new dead heartwood. Parenchyma are usually at a boundary layer in a growth increment.

Don't ask me around a camp fire about this stuff, it's not from memory. You know the "saying, use it or lose it". :D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Rocky_Ranger

WDH, I wuz just a messin' with ya  ;D, I really expected to get clobbered by some good natured ribbing........
RETIRED!

DouginUtah

-Doug
When you hang around with good people, good things happen. -Darrell Waltrip

There is no need to say 'unleaded regular gas'. It's all unleaded. Just say 'regular gas'. It's not the 70s anymore. (At least that's what my wife tells me.)

---

Ianab

Quote from: sawbuckacres on December 16, 2009, 05:53:01 PM
Interesting !  So, the thickness of the sap layer is mostly a function of the tree's health, than of age, as I have been told.  You know how difficult it can be to find store-bought lumber that will remain straight if it is stored long - I always thought that was because much of today's commercial lumber was cut from young trees that were primarily sapwood.

I'll have to do some experimentation this summer when I fire up the mill.

The width of the sapwood gives you an indication of how fast the tree was growing. The sapwood will generally be the same number of annual growth rings. Exact amount depends on the species, but say it's 10 years. If the tree is only growing 1/10th" per year then the sapwood is about 1". If it's growing 1/2" per year, then you have about 5" of sapwood.

An old tree growing in an established canopy will have the slow growth, while a youing vigorous open growing tree will be growing fast.

The unstable timber cut from small logs is true. But it's not the sapwood, it's the juvenile wood from near the heart. With a small log every board will from near the heart, but wont have the heart centred, so it's likely to be unstable.

Our local pine trees are harvested on about a 25 year cycle and dont get old enough to form heartwood at all, it's basically all sapwood. But the logs are up in the 24-36" range and you can saw nice stable timber from them, and chemical treatment covers the durability issues.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

sawbuckacres

Great stuff ! Thank you all so much.

;D ;D ;D

SwampDonkey

Quote from: Ianab on December 16, 2009, 10:56:47 PM
The sapwood will generally be the same number of annual growth rings. Exact amount depends on the species, but say it's 10 years.

I don't quite agree there, since it's been shown that sapwood ring counts can be from 10-30 rings difference in many species. There are some species however it may correlate better with that have under 5 rings of sapwood, like black locust. Sugar maple and beech aren't a wide variance, maybe 10 rings difference on average. Ours grow slow here, so them rings are mighty tight unless your growing a yard tree, even then a beech seems slow to grow compared to a maple.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Ianab

Quote from: SwampDonkey on December 18, 2009, 02:51:44 AM
Quote from: Ianab on December 16, 2009, 10:56:47 PM
The sapwood will generally be the same number of annual growth rings. Exact amount depends on the species, but say it's 10 years.

I don't quite agree there, since it's been shown that sapwood ring counts can be from 10-30 rings difference in many species. There are some species however it may correlate better with that have under 5 rings of sapwood, like black locust. Sugar maple and beech aren't a wide variance, maybe 10 rings difference on average. Ours grow slow here, so them rings are mighty tight unless your growing a yard tree, even then a beech seems slow to grow compared to a maple.

Yes, you are probably correct. I would guess there is also a correlation between age of the tree and the number of sapwood growth rings?

Seems that a 20? year old tree that is just starting to form heartwood would have 19 rings of sapwood, where an older mature tree might be down to 10 or less, so it's not exatly related to years of growth. Probably all sorts of enviromental things come into it as well.

But you can still judge how vigourus the trees growth was by the width of the sapwood.

Just an example of one of our big cypress logs. The heart/sap is very defined and about 8 years growth. (2-3")


Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

SwampDonkey

Thusly, tree health and vigour. I can half except age, but knowing it's tied to health. Although, health and vigour are the underlying factors some species no matter how healthy they are, are not efficient users of carbohydrates. Too much produced, that is stored and unused and becomes lethal to the parenchyma cell after being polymerized also killing adjacent cells.

"But you can still judge how vigourus the trees growth was by the width of the sapwood."

Ring width of the sapwood in inherently narrow sapwood species, since the number of rings don't vary by more than a couple rings. Ring width, along with sapwood/heartwood ratio in wide sapwood species with many rings. Like I explained about sugar maple heartwood being a large percentage in some trees and others it's tiny around the juvenile wood. But what looks like sapwood can also be heart not yet oxidized in some species or may never change dark at all. They classify them into 4 groups of sapwood: 1) sapwood trees - alders unless over mature, 2) ripewood - fir, pine, spruce (no pigmentation in the heart), 3) regular heartwood - oak, walnut, cherry, 4) irregular heartwood- ash (parenchyma cells only are pigmented, surrounding ones aren't). 

Ring width is real narrow on sugar maple forest grown in my area. Takes 50 years at least to get to 8" unless a yard tree. I have two 80 year old yard trees over 25" each. I have a 25 year old yard beech that is not quite 4", disease free. It's probably closer to 30, since I transplanted it as a 14 inch seedling. All growing in soil like a good garden. ;)
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Ianab

Definately different for different species.

Not all trees in NZ grow like weeds. I was down the back garden today checking on my trees. The Rimu that I planted when I moved in, a bit over 5 years ago is now about 6ft tall, and maybe 1" dia at the base. Thats pretty good growth. Give it 100 years and it might make 100ft, by 400 years it should be worth milling.

The Miro beside it is growing slower.... ::)

Not to be discouraged, we went up the road to a native tree nursery and bought a Totara, Kahikatea and a Kowhai as well.

It's a LONG TERM project  ;D

Good news is that we are starting to see some more native birds around the street, mostly hanging out in the introduced ornamentals (Banksia and cherry), but it's a start.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

tughill

I was thinking that to avoid both heartwood and sapwood, he was going to glue a bunch of bark together to make beams. ;D

It is definitely better to fell and saw lumber in the winter.  Traditional logging and sawmilling was always done in winter, for good reasons:

Logs stay cleaner being skidded on snow, which cuts down on saw maintenance.
Less damage to soil, as it is frozen, less mud, erosion etc.
Lumber will not mold.
Softwoods will not bleed pitch all over the place, on tools equipment, on your hands and clothes.
And contrary to popular belief, lumber that is properly stacked and sticked will dry in winter no matter how cold, although probably a bit slower, which is a good thing for internal tension/warpage considerations.

I'm sure there are others, but if I had a choice, I would log and saw in the winter.
"Those who hammer their guns into plows, will plow for those who do not."- Thomas Jefferson
Local Farmer here won 10$ million in the lottery, when asked what he was going to do with his winnings, responded, "Keep on farming until that's all gone too."

golden foot

 All the science is interesting. There is a lot to learn. Just from a practical standpoint I prefer "bug killed" Douglas Fir for my mill. It just seems to make better lumber. The moisture content of the logs averages around 20%. The lumber doesn't warp or shrink as much. The flitches weigh less and burn easier. The lumber air dries faster and has a beautiful color. Another way to do it is deck the logs for one to two seasons depending on your climate, then mill the logs. I am lucky where I live because it is low humidity in the summer and frozen in the winter so not much deterioration or stain in the logs. You could even "cross stack" the logs to get them to dry out and not get slimy.
SOLO 103CC SAW PRENTICE 410 LOADER CHRISTY YARDER,EAGLET Motorized CARRIAGE TIMBERJACK AND NEW HOLLAND SKIDDERS JOHN DEERE 550 DOZER LUCAS 830 MILL BIGGEST TREE FELL: 80,000 BOARD FEET WM LT40 Manual

MWnBC

    Hi.
    One quick question.
    Why are sugar maples tapped in the winter ,when they are dormant ?

    Mark

beenthere

How about in the spring, when the sap begins to flow.   :) :)
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

stonebroke

You have to get every thing inplace before the sap flows or you will miss out on the early runs.

Stonebroke

oscar not the grouch

Quote from Beenthere on Dec 15th, 2009
"When the wood dries it will shrink. If the grain is twisted, then the piece of wood will twist when it dries. "

Hi there,
Very interesting subject. I have just recently cut 80 Tamarack trees (eastern larch) this past November 2009 which I intend to log out this coming Spring and have it milled as framing lumber for my future camp. I may have some milled to use as flooring boards as well, I've seen some and they are very nice looking...nice grain.

Speaking of grain, I have read in John Laird Farrar's book "Trees in Canada" including northern US, that tamarack has a "spiral grain". Now does this mean that I will end up with a whole bunch of twisted 2x after it has air dried?? Would it be better if I had it kiln dried??

WDH

I am not familiar with tamarack, but in air drying the spiral grain hardwoods like sweetgum, blackgum, hackberry, elm, and sycamore, you can expect some twist and warp, but by no means will all the boards be that way.  Enough will to get your attention, though  :)

I think that kiln drying would help as the drying conditions are more controlled than with air drying, and there should be less degrade.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Ianab

Sawn boards warp as they dry because for some reason they shrink unevenly. Maybe because they have reaction wood (from a leaning tree), large knots, internal stress etc. If the tree has grown in a spiral then it's going to have grain going in different ways along the length of the board, so that is likely to be unstable too.

Kilning or air drying doesn't change it in any big way. Best way to keep it straight is to hold the whole drying stack down so it cant move. If you can hold it straight until it dries it will generally stay that way when you unstack it.

Lots of weight on the stack, or some big cargo straps that you can tighten up each week to keep the pressure on it.

Some boards are allways going to misbehave, but you can squash most of them into submission.

Some tree species are more prone to spiral grain than others, Thats probably what you read about. Not all trees will exhibit it, and it will be to different degrees. You can generally pick it by looking at the bark.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

golden foot

It seems like there is still some unansered questions about this post: one is still why do log home builders using Doug Fir demand that the trees be cut in the winter? I am thinking that there must be a lower moisture content in the sap wood even though it has been established that all of the moisture doesn't go back down to the roots and hibernate like a bear. If you think about it, in the fall months when the days get shorter, the temps. get lower, the photosynthesis process slows along with the growth rate. If you think about rubbing the bark off a tree when you are skidding logs in the spring versus tighter bark in the fall. It just makes sense that there is less available moisture in the tree during the fall and winter months. When the tree is frozen there is obviously no "growth" going on. Any other thoughts on this? Also to consider where Sawbuckacres lives gets a ton of snow. So there is a tradeoff in the practicality of harvesting in the winter.
SOLO 103CC SAW PRENTICE 410 LOADER CHRISTY YARDER,EAGLET Motorized CARRIAGE TIMBERJACK AND NEW HOLLAND SKIDDERS JOHN DEERE 550 DOZER LUCAS 830 MILL BIGGEST TREE FELL: 80,000 BOARD FEET WM LT40 Manual

logwalker

Doug Fir is most definitely lighter when cut in the dead of winter. The tree has gone dormant and pulled a lot of the moisture back to the roots. And the humidity in winter is less also and that has a direct effect. Joe
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

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