Reaction wood

[DC]

I've worked a few Douglas Maples that have dried into fairly extreme reflex, some up to 6". Most of this pulls out fairly early in tillering. I was wondering if anyone has a theory about what is happening here. If it pulls out from 6" down to 2" is that considered 4" of set? I'm making the assumption that set is slightly crushed belly wood. If this disappearing reflex is not set, what could it be?

[gfugal]

I would say it is set. Set isn't the same as string follow. You don't need string follow to get it.

[PatM]

If it's dried into reflex I'd say the back is shrinking the same way sinew does and the belly dries in an elongated position and you are just moving things back to their natural shape when bending.
 I have no interest in the endless discussions of the semantics of set and string follow.

[JWMALONE]

I call it warpage . I've always thought of it like Pat M said, you're just pulling it back into its original position. You didn't do anything to get it, so you haven't lost any thing when it leaves. But I suppose every one has a different way of thinking about it.

[BowEd]

DC...Don't know about douglas maple but when I have hickory do the reflex thing on staves while drying.After tillering them to bows and they are flat profile or slightly string followed if a person heat treats the belly you'll be surprised as to what will happen.Even without clamping it into reflex and giving it a heat treatment that hickory will reflex back on it's own quite a bit as to what it was.After retillering poundage gain off it is a better bow holding reflex again.

[Badger]

  Set is one of those things that is worthy of some detailed research. Not all set is really that bad and some kinds of set are terrible. I don't think we know yet how to identify different types of set. One of the biggest clues I have come across is that bow that take set but return to their natural shape or most of their natural shape after resting tend to loose more power than a bow that took some set but remains stationary or almost stationary after unstringing. I have had bows that didn't really appear to take much set but were so overstrained they were like rubber and the back would simply pull them back into shape. How well your early draw weight corresponds to your unbraced profile is probably the best indicator of all. It takes a little bit of experience and a few bows under your belt to know what it should feel like when it looks a certain way but that just goes along with learning a trade and becoming proficient. There are so many variations in profile it would be impossible to list a suggested early draw weight number.

[wizardgoat]

Doug maple is probably very close to vine maple.  Using the tension side of VM stave, you’ll often gain even more reflex as you rough the bow out. PatMs sinew reference is a good example.
Check out Gordon’s vine maple bow build, he talks a bit about this, and shows a good method of exercising a bit of it out.

[gfugal]

  Set is one of those things that is worthy of some detailed research. Not all set is really that bad and some kinds of set are terrible. I don't think we know yet how to identify different types of set. One of the biggest clues I have come across is that bow that take set but return to their natural shape or most of their natural shape after resting tend to loose more power than a bow that took some set but remains stationary or almost stationary after unstringing. I have had bows that didn't really appear to take much set but were so overstrained they were like rubber and the back would simply pull them back into shape. How well your early draw weight corresponds to your unbraced profile is probably the best indicator of all. It takes a little bit of experience and a few bows under your belt to know what it should feel like when it looks a certain way but that just goes along with learning a trade and becoming proficient. There are so many variations in profile it would be impossible to list a suggested early draw weight number.

I think we should come up with some terminology for the set that isn't as detrimental but more of an undoing of a reflex/recurve that was induced whether naturally through drying or by heat.

I call it warpage . I've always thought of it like Pat M said, you're just pulling it back into its original position. You didn't do anything to get it, so you haven't lost any thing when it leaves. But I suppose every one has a different way of thinking about it.

Jwmalone suggests it as warpage, so maybe that's a start. However, I tend to think of it getting reflex not losing it with that term.

[DC]

I wonder if it would be better/different to tie it down while drying. Then all those cells would dry in the position we wanted. Can't think of any way to test that though.

[willie]

Is it true reaction wood, that is having more cellulose or lignin on one side of the limb stem compared to the other ?
I have also seen staves from straight  trucks, where the difference might be more about drying than cell differences.
Two different reasons for the reflex might demand two different understandings of the way the wood tillers.

[JWMALONE]

I wonder if it would be better/different to tie it down while drying. Then all those cells would dry in the position we wanted. Can't think of any way to test that though.

DC, I stack and sticker any green lumber I get, usually rough cut boards. Even if it were a stave sized log or roughed out stave I would definitely strap it down some how. green wood left to its own devices does strange things.

[vinemaplebows]

Douglas maple from my neck of the woods is a much lazier wood than vine. I also noticed (here) the growth rings tend to be much larger by comparison to vine. Douglas maple will end up much thicker than vine to obtain the same draw weight in comparison, just my observation.

[DC]

There is no Vine Maple(except ornamentals) on the Island. Maybe I'll get some someday. I'd heard they were much the same. Doug Maple is very light but it makes a good bow.

I've kinda thought that maybe it was better to let wood dry loose so it can take the shape it wants. I thought that if I strapped it down it may build up stresses inside that may come back to haunt you as you remove wood. I'm probably wrong.

I don't know if it's true reaction wood but I mark the "up" side of the tree when I cut it and it always bends "up".

[Badger]

  If Doug maple is the same as what we call soft maple ( Home depot) then I say it will make a bow but needs to be wider and thicker than vine maple, much less dense. Closer to polar.

[DC]

I'm not sure but I think "soft Maple" is Big Leafed Maple. I'll see if I have an off-cut so I can measure the SG. Doug Maple is a small tree, maybe 8"dia max. Growth habit is much like a Vine maple. Too small for any commercial use I would think.