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Interesting approach! I can't wait to see how it works out.

I've been following a little more traditional method (though I'm trying a couple new things ((to me)) just for fun). This stave has some really problematic knots, and I'm not sure it's going to want to hold together. But either way, I'll show the progress, and the methods will be applicable to other projects other guys might be doing (I hope).

I removed the sapwood and the intergrown/weird heartwood, to get to a preliminary ring, and roughed out the bow a bit oversized. Looking at the stave where it is, the twist is more severe than I had initially thought; but I think it is still do-able. However, heat correcting is such a standard and common method working with osage that I think it will be more valuable educationally than tillering it out as a prop bow. The latter would be cool to see, but harder to show how to do... It would be a "Ta-da! It worked!"  (or not) type of thing, with far fewer photos.

Anyway, I got most of the photos I took up to now ready to upload to Photobucket or wherever (It's taking me longer to do the whole photo thing than the bow). There are over forty right now... I'll try and start posting them soon. Maybe more photos than anybody wants to see... ("OK, I get it, it is crooked and has knots!")

If you and anybody else would rather I not heat correct it, but just try and tiller it out as is, let me know (I'm probably going to heat correct it as soon as I get a chance, so it can start to rehydrate afterwards).

Ken

Typically I like to do both... Ha ha.

Ken

Ok, photos successfully uploaded.  I'll post as I can.

Ken

Awhile back, Sleek was asking about an osage stave with some twist, and I told him that often the twist isn't as bad as it looks before you narrow the bow to establish width profile (and that it looked do-able).  There was also some concern because the stave seemed to lack sapwood in some places.  He had the idea to send me the stave, and have me post a build-along, while he did a build-along with its sister.  Hopefully it will be of some interest or educational benefit, regardless of the results.

First thing I want to say is that it was very generous of Sleek to supply the stave and come up with the idea.  I'm going to be making some comments about how tricky this stave is or whatever, and I really don't want it to seem like I am complaining or bashing Sleek in any way!  The whole reason for this project is that it was a tricky stave.  That's the point!  Ok, then...

Here's a bunch of photos showing the stave, with its knots, twists, bug damage, and dried out or missing sapwood.  I'm going to cut back on how many photos I was going to show...

It was about 51 3/4" long, and maybe a bit over 3" wide at the widest when I got it.  Sleek asked what specs I would go for...  Not sure yet, but it will be as long as I can make it (about 51" n/n), as wide as the knots let me make it (maybe 1 1/4"?) and maybe about as heavy as the width lets me make it...  Guessing it might yield 40# or 50# at 25".  Either that, or nothing...  It could break!  Also, I might decide to sinew back it, in which case the draw length could be a couple inches longer.  We'll find out...  It's going to depend on the knots, and how the heat correction goes.





When you sight down the crown, it looked like it was more of a side to side problem than a twist problem.





But looking at it really carefully, you can see Sleek was right about it having about 90 degrees of twist to it.  Hold up a couple pencils along the red arrows in front of your screen...  It makes a 90 degree angle.





Here's a better look at the growth rings.  You can see the damaged sapwood.  Don't worry about that or the end checks.  They won't be in the finished bow.





You can see the other end is higher crowned.  Again, that knot and those end checks will be gone when the bow is roughed out.

Pretty interesting to study the grain and see what is happening in the growth rings around that knot, hmmm...?





A closer look at some of the knots:








A good chance the one closest to the end will be bypassed; and if not, it's close enough to the end it might not matter much.  That one on the right, though... 





Same knots, different view...








Bug holes.  All but one disappeared with the bark and the sapwood.  It is about five inches from the end, and may disappear as I chase the final ring.  If not, shouldn't be a big deal (I hope).





There were a bunch of patches like this where the sapwood was damaged.  Later, when I was chasing a ring, it also looked like there was some crossover between sapwood and heartwood in places.  I speculate damage to the tree (lightning, bugs, sun, or all of the above).  Last weekend, my wife and I saw the stump of a tree, where the tree had been severely damaged, and the bark grew into the tree to protect the injury.  There was essentially an island of heartwood surrounded by bark, within the heart of the tree (surrounded by wood and then bark, again).

In this photo, you can see a divot running to the left from the knot.  That demarks a trough all along the bow, where the stave went from thick to thin.  It pretty much made it easy to decide where to narrow the stave, later...

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Ok, next I removed the bark and sapwood.  In the photos, you can see the weird damaged sapwood.  In some areas, the sapwood underneath was lighter and clean looking.  In the first photo, you can see the bug hole, about intersescting the drawknife handle.  I used my dull drawknife for this phase, and switched to a sharp one for initial ring chasing.

















Once all the bark was removed, I could see enough to be able to do a simple rough width profile.  A lot of times I will chase a ring first, even  though it means quite a few more square inches I have to deal with.  But in this case, the trough down the length of the bow made it very clear where the crown was.  It also would have been very time consuming for me to chase a ring on a long indented piece of wood like that...  So I took a best guess and drew some lines to attack with the bandsaw.

Here's those two knots from before:
























Result of the bandsaw work:












You can see in this last photo that the side to side bend sort of cancel each other out.  You could tiller this bow out as is, and the string woud bisect the handle.  You would just have to have the twist sort of untwist as the limbs bend.





At this point, I've left plenty of extra width.  I'll be reducing and refining the width profile more and more as I go along.  Before I go too far, I want to establish and refine my back ring.  Usually, I do a back ring first, then do my heat corrections.  This allows me to reduce the thickness profile, giving me less wood to heat up.  I can't really reduce the thickness until I get my back ring, or I risk ending up with too little thickness.  I didn't show it, but the pith is showing on the belly, so by the time I get rid of that, I only have so much thickness left.

The trouble with doing the back ring first is that often times I'll get some cracks from the heating sessions.  Not a big deal, as they are along the grain; but a pain, nonetheless.  Putting oil on the back helps quite a bit, but if there is a chance I'll be sinewing the bow, I'd rather not soak my back ring in oil...  Hmmm...  So, I chased an initial ring, thinned the bow just enough to (hopefully) get by with the heat corrections, and I'll do those corrections in the next few days (I hope).

Oh, another reason I'm trying it this way is because it is the way that Stim Wilcox talks about doing it (if I didn't read it wrong) in his book The Art of Making Selfbows.  I thought I'd give it a try...

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Next, chasing the initial ring.


Hopefully this bug hole will disappear by the time I get my final growth ring for the back.





That knot on the end had all the growth rings piling up.  Looks like a scary mess, but I pretty much was just ignoring it (and sort of using it to stop the drawknife).  Don't worry, it's going away.





The edge of the bow will be inside of the vertical line on the right where the grain gets weird.





Back at that knot cleaned up with belt sander.  Poof!  Mess gone.





Here's the other end, just to compare rings.





The high crowned end of the stave is easier to chase a ring on...  It's more narrow, so there is less surface to worry about.  Only confusing thing is where the steep sides go vertical, you are seeing many rings at once.  Just have to stay focused; but it is disconcerting, because I usually like to chase the edges first (since they will be removed later, and it gives me room to make mistakes).  This time, that was the wrong method...  It wanted to lead me further into the stave than I want to go. 

The initial target ring is about in the middle.





Maybe this shows it better (same photo, with red lines added):





I'm leaving the knots alone until the very conclusion of getting the back ring ready.





The other end is a little trickier, as the rings are thinner, and the sapwood got tangled.





The bug hole and the little knot or blemish near it are getting smaller and smaller as I go deeper.  Hopefully they will disappear.





The knots on the side will be off the back, but some of them will be on the belly.














Good thing I plan on going deeper, as I carelessly got some drawknife tear-out.








See the cracks in the knot in the photo above?  That's one reason I soaked all the knots in cyanocrylate glue.











If you look at the last few knots, keep in mind that they are angling towards the belly, not running straight through from side to side.  This means they will tend to get lower towards the belly as I narrow the bow.  If I narrow the bow far enough, they will actually disappear from the side, and be only on the belly.  Unfortunately, I don't think I'll be able to narrow and thin the bow enough to make them disappear.  I'll try to get them on the belly, and hope they don't cause trouble.  It may be wiser to have them on the side...  Perhaps in the middle where they don't fail in either tension or compression.  Sadly, I don't know which is better.  Usually I try to avoid them...  So I don't know everything about them I could.

This knot illustrates what I'm talking about pretty well.  This is a view of the belly, and the knot is on the corner.  You can see that narrowing the bow will lower it further, and thinning the bow from the belly will eventually make it disappear altogether.  It is possible though, that the stacked growth rings around the knot will show up in the finished bow's belly.  Not a big deal...  But one of the only problems I've seen with ipe (another dense wood) is other bowyers having failures at pin knots or swirly grain (left behind by knots that were scraped away in the process of thinning the bow?).  So, it's just something to keep in the back of my mind as I work.

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I made some illustrations to better help myself and hopefully some others think about what's happening with the knots in this bow.  Yes, let's all be "Knot heads"...  Ha ha.  Well, anyway, if nothing else, it might help to see what's happening in three dimensions, and decide how to handle each knot.

First, let's think about what's happening with those two big knots near the end of the bow.  They are angling down towards the belly, with a branch extending from the back, and also (one imagines) going down into the stave.  Look at "Cross Section View", below.  The red is the branch, the orange is the stave (no kidding, right?).  This should illustrate the situation, and why just trimming off the side of bow will not eliminate the knot from our otherwise tranquil lives.

If you look at "Top View", below the cross section view, imagine the red is where the branch comes out of the back of the stave, and the green line is where we cut to remove it.  Well, now the top view is a beautiful expanse of orange (left of the green line), and the offending red is on our shop floor.

But wait!  We turn the stave to look at the right side from the cross section view, and we notice that the knot is now sticking out of the side of the bow, near the back (see #1 in "Side View", below.  Three dots are used to show the stages of removal, to save me from having to create even more illustrations).  So, we narrow the bow further, and see that the knots moves down closer to the belly of the bow (#2, Side View).  Now it is getting away from tension work.  Maybe it is even safely in the neutral plane...  I don't know.

#3 in Side View shows what happens when we narrow the bow even further.  It starts to disappear at the corner with the belly, and it is obvious that it will be completely gone from the side (surface only, it may still be within the stave) if we are able or willing to narrow the bow far enough.

Satisfied with our work, we accidentally roll the bow over on the bench, and are presented with the Belly View (bottom right, below).  The knot is still on the belly! Well, at least it is pretty much end-on, and not too big.  #1 shows what it looks like before we round the belly.  #2 shows that the knot will get ovoid (and will have less surface area, as it is getting narrower) as the belly is rounded.  I think that removing wood from the right side at this point will move the knot left or reduce its width, while removing wood from the belly will tend to chase it to the right.





Anyway, that's my take on it, for what it's worth.  I'll be showing progress, so we'll see. 

Here's two photos from above again, to further illustrate.  Pretend they are from the same knot, and the second photo is the result of narrowing the bow from the right side.


View from back, before (pretend) narrowing.





View from belly, after (pretend) narrowing (and a soak in super glue).





Ok, I also made some illustrations to help talk about what happens if a knot or branchlet (I suppose a knot is where a branchlet was cut off the stave) runs transversely through the stave, parallel to the back.  Tim Baker discussed this in Traditional Bowyers Bible Volume 4, on page 117, in text with a drawing at the bottom of the page.  I found the drawing confusing at first, as the belly is up and the back is down.  But really, I think the same principles apply to the back (as far as moving the knot around, and reducing the amount of troublesome wood at the surface or just under the surface). 

I'll discuss this from the perspective of the belly...  We are trying to lessen or eliminate the effect of a theoretical knot on the belly of a bow.

In Cross Section View 2 (upper left, below), we see a branchlet is sticking out of the bow's side.  The rest of the branchlet seems to be parallel to the bow's prospective back and belly.  Note, only the branchlet would be visible (or the knot left behind if it was cut off), so the actual angle of the knot would have to be inferred.  It may go all the way through.  In our illustration, there is a knot opposite the branchlet on the left side, where the red rectangle ends.

In Cross Section View 3, below, we've removed belly wood until the branchlet has started to be removed. 

Belly View 2 (lower left, below) shows two progressive situations (From top down in the same illustration, to save time and space).  As belly wood is removed (as in Cross Section View 3), we would probably start to see some swirly grain around the branchlet, well before we cut into the enclosed branchlet.  If we continue removing wood to get to what Cross Section View 3 shows, we'll have a branchlet that has been bisected lengthwise, running across the belly.  Neither one of those situations is optimal...  Especially the second.  It leaves a line of weak wood right across the belly (or violated grain across the back, if we were talking about the back).

Belly View 3 builds on Tim's illustration from TBBV4, and shows red dots where the branchlet was cut across if we radius the belly.  The branchlet still runs through the bow, but on the belly, there are just the ends exposed.  Note the are different sizes and shapes.  The illustration isn't in 3D, so you have to imagine the knots are sort of on the sides or corners.  We round the belly to put them there...








I hope that was helpful, and knot too confusing (couldn't help the pun, just once more).  Even if confusing (or even wrong), it should give some food for thought...

Oh, here's a photo from above again to further illustrate the situation in Belly View 2.  Look at the swirly grain where the knot approaches the belly of the stave (with its end, not parallel to it, but it shows what we're talking about). 

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Ok, so here's where the stave stands for now.  After doing a very rough initial ring chase, I narrowed it just a bit further.  All knots soaked in thin super glue.


Before narrowing:









After narrowing:






Back view from uncrowned end.





Belly view, same end.  Note grain gets crazy at endl, which shouldn't be a problem.





Feel free to post comments or questions, please. 

I'll show the stages of heat correction once I've done them.  There will be a period of at least a week after that where I can work on the bow but not bend it.  Please don't get impatient...  You wouldn't believe how much I have to do (other bow projects, etc).

Ken

Not a bad idea, John! I prayed a little when I started, but probably should be more diligent in that regard! (and if you remember, thanks)

Yep, this short there's no reason not to make it bend through the whole bow.

Ken

Thanks for sending me the better stave! I don't think that bug hole will be there after I chase the final ring; but even if so, it and the swirly grain on the other end are close enough to the end of the bow that I'm not too worried about them.

You sure have some troubling knots there, especially the ones that are near or actually on the edge of the bow. I would definitely try and see if I could do something about those (whether narrowing to get rid of them, or whatever). For punky knots, I would consider cleaning them out to good wood. You can also soak them with super glue if they aren't too punky. Another trick is a dutch plug (where you drill it out and put in sound wood), or a "liquid dutch plug", where you fill a hole with super glue and sawdust (compacting it in using several sessions).  Also, there's nothing wrong with a hole through your bow, provided you have enough extra width at the hole.

You may want to consider rawhide backing that stave after you deal with those knots, and before you start bending it. It would tend to interfere with finding out about the idea of cutting diagonally across the grain to avoid the twist; but I think it would be wise, and better than breaking the bow.

I'm not sure I understood how you are using the belly radius to accomplish protecting the knots.  I guess when you post photos of it later I might have better luck.

I think both staves have knot trouble... Which makes this a good opportunity to grow and advance knowledge (our own, and anyone interested who's following). I really don't look at this as a competition or whatever. I don't want ego to get involved at all. That just blocks the learning process. I'm not going to get bent out of shape if my stave fails... I've broken much nicer staves than this, whether through mistakes of my own, or even when I thought I did everything right. Bottom line is, have fun and learn, that's my goal.

Ken