Understanding wood fiber -theory.

[davidwyby]

@gf beranek talks about understanding hinge fiber. I got to thinking about how wood splits more easily when split parallel to the growth rings (I think this might contribute to barber chairing on the back cut). Also about which way is desirable to have the grain in an axe handle. They are more flexible to the side, partially due to shape, and I think partially due to grain. Finally, about how logs are milled to produce boards with different grain patterns for different purposes/strengths.

1/3 of the way in, the cut is relatively parallel to the growth rings. I think wood fiber holds and bends more (or pulls and compresses more) when bent flat to the the layers/rings. If the hinge is in the center of the tree, the rings/layers are 90* to the hinge/bending direction and it seems to me would resist bending more and be more brittle.


Species, species, species....

 

[CurSedVoyce]

Wee have a thread on this forum somewhere.....

 

[gf beranek]

Definitely, understanding wood fiber is very important to what we do.

 

[Bart]

Isn't splitting stubborn wood species dependent? I know stubborn locust will chip off fracturing on the ring surfaces. Problem is I can't remember if another species behaves with radial splits. Could it just be that a chord-cut is simply shorter/less wood surface to split than a diameter cut? But that ignores the separation along the ring boundary. Do videos of barber chairs show along-ring splitting or chord path - I think chord path.

 

[flushcut]

Cut it like you stole it, lol.

 

[davidwyby]

 

[davidwyby]

So… back to that grain thing. This post by @Burnham about springboards got me thinking about it again.

 

[davidwyby]

Hinge parallel to the rings 1/3 in vs 90° to them in the middle of the tree probably better…

 

[davidwyby]

Forum suggested this thread :

hinge wood dynamics

Per Jerry B's suggestion that there is no finer subject " in the trade to spark insights and opinion" A careful study of this video gives some insight into the mechanics of the hinge wood when there is some height left to the fibers at the front of the hinge. I accomplish this by using the...

www.masterblasterhome.com

I still think the hinge is pushing and pulling more than bending, in some species at least. The hinge bends or holds until the front can’t compress any more and pulls the rear apart. Or the face closes. Therefore, a gap face allows more fiber on the front half to crush and bend. A triple hinge creates even more room for compression.

 

[Kaveman]

Wood bends. This involves tension and compression, i.e. pulling and pushing. This, both lines of thought are correct.

However...

Species introduces countless variables, then there is the variability of specimen. In the high altitude, arid environs of the mogollon rim, growth rings are typically tight, the trees a bit harder and more brittle than trees of the same species found elsewhere. Then there's the variability of urban trees. Has this tree been watered, does it receive more or less drainage due to the location of buildings or a leech field? Will it have the expected tight grain, or has this thing been watered and maintained for 50 years, making for a hard, dense core, and comparatively soft and pliable material for most of its bulk?

Thus, it's all theory, and the best part about a theory, is that it's never wrong. Experience establishes general guidelines, judgment acts with in them.

 

[davidwyby]

 

[SeanKroll]

Good explanation of the reason for sapwood cuts at the end.

 

[davidwyby]

Pretty interesting to see felling from presumably an engineer’s eyes.

 

[davidwyby]

I think the reason conifers hinge more is they pull More longer fibers (the dark ones)…and presumably compress more (the light ones)

 

[SeanKroll]

I think of conifers and angiosperms being like leopards and crocodiles...both animals have the vertebrate body plan, are quadrapedal predators with claws and tails, 2 eyes, 2 hearing organs (I think), teeth and tongues, digestive tracts, cardio-pulmonary systems, etc. Very, very different at the same time.



Light part of the ring is early growth, dark is late growth. Boards wear down more between the late growth rings.




IDK. So much going on at a cellular level!

 

[davidwyby]

The white is kinda like cork or sponge. The brown is tough.

 

[Kaveman]

Throw that crap away or bolt it to a wall! No hand should ever be forced to work that garbage again!

I'd literally walk off the job if you handed me that. Or I'd snap that handle off intentionally in about 30 seconds.

And it's a square shovel, with no evidence of concrete! That's a travesty in and of itself, as a square shovel should only ever be used or moving and rough shaping mud, and that's it. So unless that thing was the world's worst dustpan all its life, it's been misused. I pity all the poor fools who lacked my fortitude to refuse to fight the tool all day.

Any use other than those previously described is tantamount to digging a nail put of a board with the claw of a finish hammer. Yeah, it'll "work", but do you not own a cat's paw? Get the right tool for the job, and never make an employee suffer for no good reason.


Ranty pants coming off now, sorry, that dang thing just stroked me wrong.

 

[CurSedVoyce]

At least gorilla tape the handle


.

 

[davidwyby]

That shovel is for shoveling the grit back into the grit blaster

Desert and blast ricochets eroded the soft fibers away

 

[lxskllr]

I have a couple tools with pretty gnarly handles. Both I bought used. One is an ancient coal shovel I bought for snow, and the other's a pitchfork I recently got for moving chips. Both are good enough, but it's better to wear gloves with them.

 

[Tree09]

Flat shovels are good for scooping up heavier material on concrete too, and for scraping up dirt on concrete and other hard surfaces. And yes the handle looks terrible, but a bunch of mine look the same tho I'm going to use it for a few minutes, not all day, so i just wear gloves, good enough for me.

 

[Marc-Antoine]

I like these rough handles. They give a better grip and don't tend to slip with the sweat/wetness. The possible splinters aren't a real problem because the sharp bits and fractured fibers are in the first rank to be demolished by the weather or the mechanical abrasion. Basically, all is rounded.
An other advantage, your skin is less likely to absorb some nasty chemicals from the factory finishing.

 

[lxskllr]

I'm halfway. I like when a tool's down to natural wood with no finish. Dings, scrapes, and other battle damage make it better, but I prefer stopping short of weather worn. I pretty much always wear gloves doing "heavy" work, so jaggies aren't a huge deal, but it would be better if they weren't there.

 

[Kaveman]

Natural born contrarians, every one of you.