Is fretting or chrysalling related to grain orientation?

[Flntknp17]

All,

I have been pondering the relationship (if any) between frets/chrysals and grain orientation in the limbs of backed bows made from lumber staves.  My question is this: does a bow made from rift or quarter sawn wood have a greater resistance to fretting than a bow with the same physical dimensions made from a flat (or plain) sawn board?  I ask because I bought two nice pieces of hard maple (enough for four bows) from my local hardwood lumber yard and the first two bows were quarter sawn and they turned out really well and have hundreds of shots each, no issues.  I was a little excited about the other piece because it was almost perfectly plain sawn and I thought it would look nice as finished bows since they would have grain that would look just like selfbows.  I got the first one as far as ~20” draw last night and it fretted BIG TIME.  There was not a hinge and I had no warning of impending doom for the bow.  All three bows are backed with very thin bamboo and otherwise identical save for the grain orientation (quarter versus flat). 

I’d love to hear any thoughts.  Maybe it was just random??

Matt

[Yooper Bowyer]

I have had a lot of trouble with fretting on maple lumber.  The worst is where there is a small roll in the grain. 

You didn't say whether the frets where localized or not, but maybe the flat ringed board was less dense than the edge ringed board.

[George Tsoukalas]

I think fretting is all about having a good tiller.. I have not noticed any frets in lumber bows at least that I can remember. Jawge

[bownarra]

Grain orientation doesn't matter.
Sounds like you have a dodgy board. There will have been something wrong with your tiller. Unless the frets are all along the limbs, evenly spaced.
Boo on maple is not great. The boo is too stiff. It would work but not an ideal combo.
A self board bow from maple with heat treated belly would perform better than one backed with boo.

[scp]

Grain orientation doesn't matter.

Usually but not always. If you have a plain sawn board or stave on the belly and it happens to have the weak early wood that is exposed and rather thin, that weak layer can chrysal relatively easily. I think this happened to me once, out of dozens of bows. You can probably just sand it out without losing too much draw weight. Anyhow proper seasoning and tillering matter much more.

[Badger]

   Maple is a little more prone the chysaling than a lot of the woods we use. I always go plenty wide on maple and try extra hard to get the tiller right.

[willie]

impending doom

does the appearance of frets make the limb hinge?  Maple doesnt have extremely distinct early/late wood, but there still might be some density differences within an  annual ring, possibly showing up as areas with frets.

SCP has a good point. what if you keep tillering and just ignore to find out what happens?


just out out of curiousity, is the ring count high or low? Are the flat sawn boards denser or lighter than the edge sawn?  if lighter, maybe the design just needs to be a bit wider for the poundage.

[Flntknp17]

Thanks guys for the information.  I’ve had nothing but great luck so far with a bunch of different maple and bamboo bows so I’m totally confident that the combo works fine for the design I have.  The tiller was fine.  Definitely no hinging.  That’s something I’m confident of.  I was just surprised because I’ve had such a fun time this year playing with maple.  I always thin the bamboo to paper thin on the margins.  It’s literally as thin as it can be.  I’ll probably keep tillering and see what happens.  If it blows I’ll post a picture 😂

Thanks

Matt

[bownarra]

Grain orientation doesn't matter.

Usually but not always. If you have a plain sawn board or stave on the belly and it happens to have the weak early wood that is exposed and rather thin, that weak layer can chrysal relatively easily. I think this happened to me once, out of dozens of bows. You can probably just sand it out without losing too much draw weight. Anyhow proper seasoning and tillering matter much more.

That's is because you haven't done your job properly Nothing to do with the grain orientation. All selfbows have this 'problem' then???

[scp]

That's is because you haven't done your job properly Nothing to do with the grain orientation. All selfbows have this 'problem' then???

All stave bows are more prone to that grain orientation issue. But most premium staves would probably have no problem. But I use whatever stave I have and am not that crazy about perfect seasoning or tillering. The issue can be there even if you think you are always perfect in both. You might have been lucky probably because the issue become apparent maybe less than one in a thousand case. That does not mean it is impossible, just as your seasoning and tillering can never be perfect always. I don't think you can prove that the issue is theoretically impossible or meaningless. It is practically unprofitable. But you never know. Do you know why some wood are said to be more prone to chrysal? Are you trying to say no stave would ever chrysal with perfect seasoning, design, and tillering. Nothing is ever so simple or clear-cut with natural materials.

[RyanY]

If weak early wood and thin rings were more prone to compression issues I would think this would occur way more frequently with stave bows that have the rings feather out from thickness taper from fades to the tips. This doesn’t seem to be the case even though it sounds plausible.

The fact that some woods split differently along different axes is to me the most convincing evidence that there may be differences in properties when the grain is bent to different directions. But to say that it is weaker in compression for that reason alone would be a big assumption.

[scp]

Compression failure due to grain orientation is mathematically plausible, as any other orientations than one like in plain sawn lumber would bring out the average of all layers, instead of aggravating the weakness of a certain weakest layer. Still, even that layer is not devoid of compressive strength, and in self-bows all sections are not compressed equally. The failure would probably occur only at the most compressed section and especially when the stave is not well seasoned. But as noted, this has never been a major issue with staves. I vaguely remember just one such possible occurrence out of dozens of self-bows and we need to listen to the person who is actually experiencing it now. I would be really surprised to see it happen even after the heat treating of the belly. But the exposed weakest layer can be paper thin sometimes. In that case, we can probably just sand it out with no ill effects.

[RyanY]

Compression failure due to grain orientation is mathematically plausible, as any other orientations than one like in plain sawn lumber would bring out the average of all layers, instead of aggravating the weakness of a certain weakest layer. Still, even that layer is not devoid of compressive strength, and in self-bows all sections are not compressed equally. The failure would probably occur only at the most compressed section and especially when the stave is not well seasoned. But as noted, this has never been a major issue with staves. I vaguely remember just one such possible occurrence out of dozens of self-bows and we need to listen to the person who is actually experiencing it now. I would be really surprised to see it happen even after the heat treating of the belly. But the exposed weakest layer can be paper thin sometimes. In that case, we can probably just sand it out with no ill effects.

For plainsawn lumber or staves, that paper thin layer is usury not isolated to itself across the whole belly due to the crown of the growth rings. I think the OP posted a picture of this bow on Facebook and you can make out multiple lawyers of growth that the compression fracture crosses across the whole belly. Am I correct in that assumption Matt?