Post by: Kirkll on March 30, 2022, 01:25:20 PM
The stave is 65" in length and has pretty consistent ring spacing. When i originally had this stave given to me, i built my own draw knives and scrapers and learned to chase rings. I chose a nice consistent ring with decent thickness and have the back of it looking pretty good..... That's as far as i got...
So i'm going to start this process with questions for you experienced self bowyers, and any suggestions would be appreciated as well. It starts by reading the stave and seeing potential and taking the flaws and characteristics into consideration.
First of all i see a twist in the stave , as well as a kink in one end that may or may not be straightened with steam considering the grain orientation. The one end has a natural reflex shape that i like the looks of and would like to shape the other end to match it. I was planning on reflexing the tips a bit too.
I'd like your thoughts on what you would do, and recommendations on how to proceed.
Kirk
I've attached a bunch of photos below. If you click on the smaller photos, they will enlarge.
https://photos.app.goo.gl/k1LGMpk6JdSZYmzn7
Post by: Mad Max on March 30, 2022, 02:09:18 PM
Pat will be the most help from the group but I have some ideas too.
3rd pic. is the back? 4th pic. is the side?
If so, How wide is the stave @ that knot hole on pic. 4?
Post by: Kirkll on March 30, 2022, 09:25:58 PM
The knot is not even going to be in play. That thing is on the belly side and is only 3/8" deep. i have over 1 1/2" of thickness at the tip. It will be gone when i rough shape the limb before floor tiller stage.
Kirk
Post by: Pat B on March 30, 2022, 10:24:26 PM
Once you get to floor tiller(about 5/8" thick at the fades) it will be easier to make heat corrections. You will have to do this in sections and the lateral bends will be the most difficult so start with them. For the kink at the end of the one end I think I would boil or steam to make the correction. You may have to do this in more than one step. A lot of the other adjustments can probably be done with a heat gun, a form, a few small wood wedges and clamps.
This should get you started. Post pics along the process to help us help you.
Post by: Kirkll on March 31, 2022, 11:57:07 AM
This stave is over 1.5" width at the tips right now, and it would be easier to bend with about 7/8" width. That should still give me plenty of room for tip notch adjustment.
I'll post some photos as i make progress... Kirk
Post by: Kirkll on March 31, 2022, 01:54:32 PM
Do you think i should work on straightening this before i do the tiller work? It seems like that is the next logical step. Kirk
https://photos.app.goo.gl/ceGMqTx1uN5epMScA
One other thing..... I was considering soaking this crooked end of the stave in a bucket of water for a day before trying to steam it. I've had better luck steam bending doing this, but thought i'd ask your thoughts on this.
Kirk
Post by: Mad Max on March 31, 2022, 02:33:32 PM
Post by: Pat B on March 31, 2022, 02:41:04 PM
Post by: Kirkll on March 31, 2022, 03:55:38 PM
No don’t soak it
So what are your thoughts against soaking it Max? Time for MC level to drop back down again perhaps? Kirk
Post by: Kirkll on March 31, 2022, 03:59:56 PM
Kirk, I have heard of folks soaking wood before steaming it with success but I've never done it. What is the back of the stave sealed with? I think I would try to straighten it some at least then start tillering. Once you get to first low brace you will see how the string tracks and where more adjustments are needed.
I hit it with a little spay lacquer to inspect my ring chasing a bit closer. I use this stuff all the time for a sanding sealer, and it sands off easily.
What do you start out with on low brace height Pat? 3-4”? Kirk
Post by: Mad Max on March 31, 2022, 04:44:18 PM
I would not soak it because you would have to wait for it to dry and I don’t think it needs it :thumbsup:
Post by: Kirkll on March 31, 2022, 08:01:58 PM
Most of my experience resulted in the wood that I soaked overnight before steaming it was elastic enough to bend at a tighter radius without tearing the grain using thicker laminations. But just steaming it alone required thinner laminations. But I wasn't dealing with a solid piece of wood of any thickness.
Keep in mind this Osage has been setting for 12 years and is pretty dry.
I’m unsure how deep the moisture would penetrate the Osage by soaking it, but my thoughts were it would help the elasticity vs dry heat.
I do have heat strips I could use when I clamp up the bend that I can regulate the temp to 180-220 degrees. maybe set the timer for an hour or so at 200 and then leave it in the clamps for a day to cool. That might be helpful. What do ya think? Kirk
Post by: Mad Max on March 31, 2022, 09:09:20 PM
I know moisture is no good for selfbows, but if you let them dry you would be fine :thumbsup:
I have wet down some .050 Sitka Spruce (6 at a time) to bend into a 2-1/2" radius and it worked very well.
(https://i.imgur.com/N0ImLVH.jpg?1)
Post by: Kirkll on March 31, 2022, 09:55:28 PM
I'm going to dump this stave in a bucket of water and let it set over night, then use steam on it tomorrow before i clamp it up. I may try using a couple stainless steel heat strips when i clamp it too. The heat may increase the elasticity. Kirk
Post by: Pat B on March 31, 2022, 11:05:15 PM
Kirk, by low bracing you want to see the tight string unobstructed from tip to tip. Anywhere from 2" to no more than 4" to prevent over straining the untillered stave but to be able to see how the string tracks, where heat adjustments are needed.
Post by: Kirkll on April 01, 2022, 10:18:21 AM
We’ll see how this first bending session goes this morning. Btw… I tried a bit of floor tiller flexing after roughing the shape out yesterday and There is huge difference between a yew stave and this Osage. This is some stiff material.
One more question for you guys. Once I get ready to long string this thing, do you just use minimal depth side notches on the tips and leave that back ring intact? That’s how I did the yew staves years ago, but this Osage is a completely different beast.
I wouldn’t mind having some different tip overlay options too. I have an assortment of horn material and was thinking this black water Buffalo horn would be a good choice, but have I have no experience attaching this stuff to a stave.
Your recommendations would be appreciated. Kirk
Post by: Bowjunkie on April 01, 2022, 10:39:58 AM
I've used cow horn and water buffalo horn on many selfbow and bamboo backed bow tips. Grind the tips at an angle, groove both gluing surfaces longitudinally with a fine tooth toothing plane blade, and glue on with Smooth On ea40, clamp lightly or use rubber bands, set a shop light near for warmth. Never had one come loose.
Post by: Kirkll on April 01, 2022, 11:05:41 AM
Kirk
Post by: Mad Max on April 01, 2022, 11:20:52 AM
I just file a grove on the back of the overlay not the side
Post by: Pat B on April 01, 2022, 12:18:28 PM
I've used antler, horn, hardwood and even rawhide and veg tanned leather saturated with superglue for tip overlays.
Actually, with osage you don't need overlays even with FF type strings.
Post by: Kirkll on April 01, 2022, 01:57:00 PM
I cut that knot out of it when rough shaping it but i don't want to push my luck trying to do too much at once. I may wait until i get my tips thinned down a bit before trying to get a reflex bend. That area where the knot was located looks like a potential weak spot.... Steady as she goes...
https://photos.app.goo.gl/5fd1BCNEuixWtGTv5
Kirk
Post by: Pat B on April 01, 2022, 03:59:59 PM
Post by: Bowjunkie on April 01, 2022, 06:35:53 PM
Post by: Kirkll on April 01, 2022, 07:49:05 PM
Pat, I was actually surprised how easily that kink in the limb straightened out. But that is a rather large C clamp i used too. I believe soaking it and steaming it in boiling water for 30 minutes had something to do with it. We will see how much spring back it has after i pull the clamps. I'm going to build a radius form to reflex the tips a bit on the flat grain side next.
Back when i was building radius top doors for fancy boats, i came up with the idea of building them pre-hung in the cabinet shop. Rather than bending the top of the finished door frame in place in the door rough opening, and fitting each door to the frame. (Like they had been doing) I could use a true radius, build the doors and frames in the shop and adjust the reveal while hanging the pre hung door. I scored a few points with the cabinet shop foreman coming up with that system. :saywhat:The guys i worked with at Christensen Motor Yacht were a serious collection of craftsmen. Luthiers and fine furniture builders that could inlay your signature in mother of pearl. It was an incredible experience working with the old school craftsmen.....Back in the late 80's a lot of that work was still being done by hand. Now days CNC production has taken a lot of the hand work out of play.
But back to my point about wood bending.... What i found building radius top doors was that different types of hardwood have different spring back after bending them in the same form using the same thickness laminations. For example Sitka spruce and Sycamore would have a lot more spring back than Honduras Mahogany, or Teak. And the Teak had more that the Mahogany too. So it was kind of tricky to build door frames to match a true radius door top because you had to calculate the spring back, and use a tighter radius on your form So it fit the door top in a relaxed position. We used a lot of Urac 185 in our lamination work, and a lot of West Systems epoxy too. Believe it or not the type of glue had no effect on spring back. So i'll be curios to see how much it moves.
I think some of the wildest wood bending i ever did was building a free standing spiral stair case out of solid Teak on the aft deck of one of those fancy yachts. That my friends was a wild project.
Kirk
Post by: Mad Max on April 01, 2022, 08:41:12 PM
I did some Ornamental Iron work for 12 years and always want to do a curved stairway. and I got my chance.
It was about 110* turn to the upper floor. I took my roll bender on site and curved and twisted the upper and lower rails until I got them fitting. I screw my post (4 I think) to the treads and cut the curved pieces to weld to the post, brace it all up and took it back to the shop to finish later. the Treads were plywood when I mocked it up and Oak after they finished . I was very proud of the work I did over the years.
Post by: Kirkll on April 01, 2022, 08:56:08 PM
I've done quite a few spiral stair case railing systems and bent the rails in the field solo. But that free standing job on the yacht was a full 360 degree with no post. That inside stringer looked like a cork screw. :biglaugh: Only had a 12' inside radius, and the outside was about 3' giving us a 30" wide tread. We had to build two forms. Inside and outside, and used 1/4" solid Teak for laminations.... A whole lot of laminations too. :biglaugh: It took 2 of us about 6 weeks to put that thing together, and we had more guys handy doing the cork screw lay ups.... Fun days.... Dirt cheap wages... I loved that job. Kirk
Post by: Mad Max on April 01, 2022, 09:24:17 PM
Post by: Kirkll on April 01, 2022, 09:39:57 PM
Here's a buffalo horn tip. I may vary the grind angle a bit from bow to bow depending on the outer limb shape.
Can you explain the different splice angle changing with the outer limb shape differences? I think i got it... but... :dunno: Kirk
Post by: Pat B on April 01, 2022, 11:10:15 PM
I watched a show on PBS about building a Roman chariot I think they were in Egypt. These old world woodworkers steamed a 6"x 6" post for 6 hours in a big steam box then bent it into the desired shape. All with primitive tools and methods. Pretty cool.
I've done lots of boat work but in the mechanical areas but saw lots of beautiful woodwork on the motor and blow boats at Harbor Town on Hilton Head. Is. SC.
Kirk, I think we need to be asking you about heat bending wood. You are the expert in this group. :thumbsup:
Post by: Kirkll on April 02, 2022, 12:09:05 AM
But the word “expert” has an overtone I’m not comfortable with. How bout “seasoned craftsman” …. I can live with that one. I’ll gladly share previous experience with folks, but you’ll never learn it all our rather short life times.
Could you imagine the sum total of a man’s experience could be if we could
live 2-300 years and still retain the knowledge? Now THAT would be very cool.
I know self bows and moisture content is a big deal because it’s the moisture content that mitigates it’s flexibility to a certain point. But Bending wood with heat alone is still heating the moisture still inside the wood and making it more flexible while it’s hot. The higher the moisture content, the easier it will bend.
Where I live in Oregon, the average moisture content in all my shop wood stays real close to 12%. I can buy bone dry kiln dried lumber that is 8% and leave in in the shop for two weeks and it’s right at 12% on the surface just like everything else. I have to be very careful to bring that mc level back down before I finish a riser or bow. Especially if it’s being shipped to a drier climate.
So part of my luck with getting this thing to bend so easily was most likely the mc level of the stave was higher than normal. That , and I soaked it in water for 12 hours then boiled it in hot water for 30 minutes. That being said, I’m going to let this set in my spray booth at low humidity lever for several days before I take the clamps off. A week would be better me thinks….. I’m in no hurry to get this thing done, but I will finish it now that I’ve started…. Kirk
Post by: Kirkll on April 02, 2022, 12:31:25 AM
It’s the outside pores of the wood close and shrink when it dries, and the moisture inside the board is trapped inside. That’s why you see sprinklers on piles of logs at the lumber mills in the summer, so they don’t split open. If you are going to harvest and air dry your own wood, cut it in late September and dry it though the winter months. You’ll ge5 a much better yield.
Steaming wood before bending it helps open up those pores and let’s moisture inside making it more flexible and helps avoid tearing the grain on the outside and allows better compression flexibility too. Most of my wood bending experience was done by cutting up big ones, to make little ones, to make big ones in the form of laminations with no steam at all until you get into tight radius work.
Food for thought… Kirk
Post by: rainman on April 03, 2022, 10:09:53 AM
Post by: Stagmitis on April 03, 2022, 11:00:01 AM
Post by: Kirkll on April 03, 2022, 11:46:33 AM
Dang Bowjunkie that is a beautifull tip overlay!!!!
I agree staggy…. I think I’m going to try this on this Osage bow with some water Buffalo horn material. That is so cool. :notworthy: :notworthy: Kirk
Post by: Kirkll on April 14, 2022, 08:56:17 PM
Now i've got the other end to contend with that looks like a snake. One end has a perfect back set shape and i'm not sure if i can get this as nice as the the other end, but i'm going to give it a try.
This is what i'm dealing with. I didn't mind soaking and steaming the tip on one end, but i'm not to thrilled with the idea of soaking the whole limb in water. Any suggestions would be appreciated.
Kirk
Post by: Mad Max on April 14, 2022, 09:21:01 PM
Pat should be on here soon.
Post by: Pat B on April 14, 2022, 11:07:18 PM
If you don't have a full length caul you can work the kinks in the limb out one at a time with heat, oil, clamps and and a piece of 2x4.
Post by: Kirkll on April 15, 2022, 12:25:37 AM
Post by: Mad Max on April 15, 2022, 07:55:59 AM
Pardon my ignorance Pat…. But I’m not familiar with the word caul. Are you referring to a form that the stave is clamped to? Kirk
Yes :thumbsup:
Post by: Pat B on April 15, 2022, 08:00:28 AM
Post by: Mad Max on April 15, 2022, 09:21:24 AM
You can straighten out the bow while inducing , reflex, R/D and recurve tips and heat treat at the same time.
Here is a 5 curve braced and not braced, not mine
(https://i.imgur.com/e1sNDcx.png)
(https://i.imgur.com/C4s1ST3.png)
Post by: Kirkll on April 15, 2022, 10:41:41 AM
I might have to build a “caul” then…. Or…. Maybe I can use my old one piece long bow form…. Hmmmmm….. I need to rebuild that form anyway. Might as well put the old form to good use.
I’m going to hook up with Casey and build a new Flatliner form together with him and show him the ropes in the not so distant future. That should be fun…..
Kirk
Post by: Kirkll on April 15, 2022, 07:16:44 PM
Do you think this is too much set back for the Osage stave? If not i could clamp it to this form....
I think it might be a bit too much myself , and require the depth of the bow to be too be too thin. I'm going to target about 45-50 @ 30" draw on this one. Your thoughts?
This form wa
Post by: mmattockx on April 15, 2022, 07:48:32 PM
I think it might be a bit too much myself , and require the depth of the bow to be too be too thin.
Define too thin? Lots of reflex increases the limb stresses (this is not a concern with FG but sure is with selfbows) and makes it trickier to tiller as the long string can be pretty misleading.
Mark
Post by: Kirkll on April 15, 2022, 08:35:08 PM
I think it might be a bit too much myself , and require the depth of the bow to be too be too thin.
Define too thin? Lots of reflex increases the limb stresses (this is not a concern with FG but sure is with selfbows) and makes it trickier to tiller as the long string can be pretty misleading.
Mark
That's what i'm concerned with Mark, and why i asked if you guys think this might be too much. Maybe i should just stick with matching up the natural set back shape on the one end and build a half form to match it, and just straighten out the wiggles on the other. I'm not familiar with this osage at all... This is pretty stiff material.
"makes it trickier to tiller as the long string can be pretty misleading."
Can you explain this long string being misleading statement? Thanks
Kirk
Post by: Pat B on April 15, 2022, 10:20:54 PM
Post by: Mad Max on April 16, 2022, 12:02:35 AM
I would get a good floor tiller to get a good bend on both limbs and then brace it to 3" or so.
Long strings pull the tips down (giving you a false reading).
When you floor tiller, shove the tip into the floor as you bend it, this will act like the tip pulling back to the other tip.
Post by: Kirkll on April 16, 2022, 10:40:03 AM
I’ve got other irons in the fire here, so I’m not rushing this project at all. But I’ll get er done eventually. Kirk
Post by: Pat B on April 16, 2022, 11:56:23 AM
I think you might want to reduce the thickness of the limbs before trying to iron out the wrinkles. Less wood moves easier with heat.
Post by: mmattockx on April 16, 2022, 12:06:48 PM
"makes it trickier to tiller as the long string can be pretty misleading."
Can you explain this long string being misleading statement? Thanks
Initial tillering with a long string is always misleading a bit, even with a flat bow, because it doesn't pull the tips around as hard as the final string and they look stiff. This isn't a huge problem with a flat bow as it doesn't really affect the bend for the first few inches of tip movement and then you can get to a low brace. With more reflex (and even more with recurves) the tips look stiff right away and many people end up taking too much material off them before they brace. Then they discover the error and are fighting to correct a whip tiller.
I would stick with Pat's recommendation on reflex. My limited experience with adding reflex to self bows says that anything much more than a couple inches adds more challenge than what you gain. Some guys can make a lot more work (Marc St. Louis comes to mind), but you have to be a master at tillering to not screw it up.
Mark
Post by: Kirkll on April 16, 2022, 09:05:54 PM
I do use a long string but only until I get a few inches of tip movement so I can see the overall bend from a distance. The long string should be only as long as the bow or like Mark said you will get a wrong reading. Once I'm sure both limbs are bending evenly I get to low brace as soon as possible. This is when you get to see the true shape of the bow and see how the string is tracking. By doing it this way I can get the corrections made early in the process so I can get to full draw soon and achieve my intended draw weight.
I think you might want to reduce the thickness of the limbs before trying to iron out the wrinkles. Less wood moves easier with heat.
I thought about slimming it down some too before straightening it Pat, but I don't want get too carried away either. I'm in uncharted waters here floor tillering an osage stave. Once its gone , you cant put the wood back..... Kirk
Post by: Pat B on April 17, 2022, 12:05:01 PM
(https://i.imgur.com/c4czWqT.jpg)
Here you see 2 pencil lines. I will reduce the thickness to the first line by making a facet with a rasp along both sides of the limbs then remove the center "hump" to a radiused belly and smooth then check floor tiller. If still too stiff I make another line 1/8" to 1/4" below the previous line and do the same as above. These lines should parallel to the back following the backs ups and downs.
(https://i.imgur.com/GPLjDpd.jpg?1)
(https://i.imgur.com/K8ZuYET.jpg)
here you can see the crown down the center after faceting the belly...
(https://i.imgur.com/G9ooOhA.jpg?1)
...and after that crown is radiused...
(https://i.imgur.com/uiP08AR.jpg?1)
...and then smoothed...
(https://i.imgur.com/FiRryoE.jpg)
these are the tools I use for this process...
(https://i.imgur.com/Yd2sfLE.jpg)
Post by: Kirkll on April 17, 2022, 07:22:10 PM
Post by: Pat B on April 17, 2022, 10:50:21 PM