Author Topic: Ring thickness correlation to density??  (Read 2969 times)

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Offline Jakesnyder

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Ring thickness correlation to density??
« on: July 06, 2021, 09:59:49 am »
This might be a dumb question and i know it's been asked and answered on here before but I forget the response, is wood always denser if the rings  are tighter? Also woods like ash and maple where most of what I've seen are larger growth rings. Thanks

Offline PatM

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Re: Ring thickness correlation to density??
« Reply #1 on: July 06, 2021, 10:13:33 am »
No.   It varies between trees.

Offline George Tsoukalas

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Re: Ring thickness correlation to density??
« Reply #2 on: July 06, 2021, 10:26:18 am »
Density is mass/volume usually in grams/cubic centimeter. It seems logical that the more wood (grams) in that cubic centimeter would make for  a greater density. So the tighter the rings the more the grams.
Jawge
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Offline ssrhythm

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Re: Ring thickness correlation to density??
« Reply #3 on: July 06, 2021, 12:29:27 pm »
If early wood is less dense than late wood, then it seems thicker growth rings would yield denser wood. 
How that correlates to bow performance…don’t know yet.
I guess wood type would be important here also.

Offline PatM

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Re: Ring thickness correlation to density??
« Reply #4 on: July 06, 2021, 02:52:12 pm »
Density is mass/volume usually in grams/cubic centimeter. It seems logical that the more wood (grams) in that cubic centimeter would make for  a greater density. So the tighter the rings the more the grams.
Jawge

   For ring porous woods you still end up with more early wood.

Offline SLIMBOB

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Re: Ring thickness correlation to density??
« Reply #5 on: July 06, 2021, 03:03:05 pm »
I would think ssrythm is right. Thinner rings have more early wood, all things equal, and would therefore be more dense. But density is only part of the equation. If it were not, Live Oak would be a top choice.
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Offline RyanY

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Re: Ring thickness correlation to density??
« Reply #6 on: July 06, 2021, 04:35:46 pm »
I would think ssrythm is right. Thinner rings have more early wood, all things equal, and would therefore be more dense. But density is only part of the equation. If it were not, Live Oak would be a top choice.

Thick ring osage seems to be light and spongy so I don’t think this holds up for all species or possibly even within a species given variability of geography and growing conditions.

Offline PatM

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Re: Ring thickness correlation to density??
« Reply #7 on: July 06, 2021, 04:45:34 pm »
I would think ssrythm is right. Thinner rings have more early wood, all things equal, and would therefore be more dense. But density is only part of the equation. If it were not, Live Oak would be a top choice.

  Early wood is the porous layer on many woods.

Offline SLIMBOB

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Re: Ring thickness correlation to density??
« Reply #8 on: July 06, 2021, 04:47:52 pm »
Yes sir. Thin ringed staves would have more early wood. ??
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Offline SLIMBOB

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Re: Ring thickness correlation to density??
« Reply #9 on: July 06, 2021, 04:50:55 pm »
So having read my statement again…thin ringed staves would have more early wood and therefore be less dense than thick ringed wood. I’m on back pain meds and I feel half looped. 🙃
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Offline ssrhythm

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Re: Ring thickness correlation to density??
« Reply #10 on: July 06, 2021, 05:08:32 pm »
I’m about to have a real good comparison for osage.  I’m finishing a bow from an indiana tree that had phenomenal late to early wood ratio.  The early layers are super thin, and the late rings are whoppers.  So far (just put first shots thru it yesterday) it’s holding the vast majority of the reflex I added (had to remove reflex from one limb and reflexes to match the natural reflex of the other limb). I came in too light, so Im about to take an inch off each end to make bow 63.5” tip ti tip.  Will add slightly more recurves and sinew backnit.

The second bow I have just about at floor tiller is an Ohio stave, and it’s early:late is not terrible, but definitely not as good as the first bow.  It is already ~ 62.5” tip to tip.  Limbs are slightly wider.  At this time, this bow weighs less than the nearly finished first bow, so it is definitely less dense than the bow with thick growth rings.  I’m going to recurve and back it  with sinew also, so while theirs will be slight design differences, they will be very similar.  The comparison will be interesting.

Im interested to see which one produces the better bow.  I tend to think that the tighter ring staves will take less set than thick ringed staves.  Why?  Well, if set is caused my compression of belly cells, my theory is that before the cells of the thin late rings in the compression plane of the belly can compress snd become damaged, the compression forces are spread into the the early wood in that compression plane which is spongy and can “absorb” some of the compression load…providing a little buffer of protection for the late wood rings in the compression plane.  I’m pretty sure that an unviolated thin back ring will withstand any normal draw applied tension, so unless the early wood layers are unusually thick, which might cause delamination toward the back, I’m leaning toward the tighter growth ring Osage producing better bows than fat growth ring Osage.  I know for sure that if two identical bows were made from those two staves I have, with draw weight and profile being identical….the thin ring stave will out perform the thick ring one by a good bit simply due to how much lighter the wood is…less limb mass to move = faster.   

That’s my theory, and I’m sticking with it till I prove myself wrong…which may be as early as the end of this week!

I’m

Offline ssrhythm

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Re: Ring thickness correlation to density??
« Reply #11 on: July 06, 2021, 05:13:23 pm »
Here is the indiana bow after its first 4 20 yard shots.  I’m about to go cut the tips off and bend It some more.  Am I crazy?!?!

Offline ssrhythm

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Re: Ring thickness correlation to density??
« Reply #12 on: July 06, 2021, 05:14:13 pm »
Dammit!  Sorry!

Offline RyanY

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Re: Ring thickness correlation to density??
« Reply #13 on: July 06, 2021, 06:20:43 pm »
I’m about to have a real good comparison for osage.  I’m finishing a bow from an indiana tree that had phenomenal late to early wood ratio.  The early layers are super thin, and the late rings are whoppers.  So far (just put first shots thru it yesterday) it’s holding the vast majority of the reflex I added (had to remove reflex from one limb and reflexes to match the natural reflex of the other limb). I came in too light, so Im about to take an inch off each end to make bow 63.5” tip ti tip.  Will add slightly more recurves and sinew backnit.

The second bow I have just about at floor tiller is an Ohio stave, and it’s early:late is not terrible, but definitely not as good as the first bow.  It is already ~ 62.5” tip to tip.  Limbs are slightly wider.  At this time, this bow weighs less than the nearly finished first bow, so it is definitely less dense than the bow with thick growth rings.  I’m going to recurve and back it  with sinew also, so while theirs will be slight design differences, they will be very similar.  The comparison will be interesting.

Im interested to see which one produces the better bow.  I tend to think that the tighter ring staves will take less set than thick ringed staves.  Why?  Well, if set is caused my compression of belly cells, my theory is that before the cells of the thin late rings in the compression plane of the belly can compress snd become damaged, the compression forces are spread into the the early wood in that compression plane which is spongy and can “absorb” some of the compression load…providing a little buffer of protection for the late wood rings in the compression plane.  I’m pretty sure that an unviolated thin back ring will withstand any normal draw applied tension, so unless the early wood layers are unusually thick, which might cause delamination toward the back, I’m leaning toward the tighter growth ring Osage producing better bows than fat growth ring Osage.  I know for sure that if two identical bows were made from those two staves I have, with draw weight and profile being identical….the thin ring stave will out perform the thick ring one by a good bit simply due to how much lighter the wood is…less limb mass to move = faster.   

That’s my theory, and I’m sticking with it till I prove myself wrong…which may be as early as the end of this week!

I’m

There was a whole thread hypothesizing that early wood contribute more to set which is opposition to your idea that early wood absorbs the compression. They hypothesized that a belly ring thick enough to not have exposed early wood would perform better.

A theory isn’t right until proven wrong. Just the opposite that we shouldn’t invest heavily in it until proven right.

Offline Marc St Louis

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Re: Ring thickness correlation to density??
« Reply #14 on: July 06, 2021, 08:07:48 pm »
There's a lot of factor that affect tree growth/ring thickness, soil condition, rainfall, soil nutrients, climate.  You could have one Osage tree growing in perfect soil conditions with access to plenty of water in one specific location and another tree growing in poor soil conditions and dry conditions nearby.  They both will have quite different rings.  Generally with fast growth you get a fast bulk up which suggests weaker/less dense wood but that doesn't necessarily make for poor bow-wood.  Density of bow-wood is good but what is better is its elasticity
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