This time 100+ pound I hope. Mid sal is 15mm. Length 44inches ntn, 70g of sinew.
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Definitely higher than 100#! 15mm thick core or when sinewed?
Even 15mm thick with sinew should get you somewhere 140 pounds.
15mm is total limb thickness. 8mm horn, 4 wood and 3 sinew. There is a lot of horn to remove. I’m aiming for 13.5mm thickness on finished bow, therefore 100-115 pound. Because I would like to be able to draw it 
Gluing horn was not ideal. I think I applied rope after the glue was already gelled. Before that it was held with clamps so there was contact but I’m not sure.
I think this one will break but don’t really care because I have one bow functional.
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I steam my core after binding with rope. It could help with this kind of problems too… Makes the glue soft and gets the pieces closer to each other when excess glue is squeezed out.
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Tepeliks are on, again, only one month after first layer. Mid sal is 14mm But unfortunately tips are only 16.5mm deep. I think 100@max is safe. What do you think ?
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Yes, that should be safe still. In Adam’s book there is the table of museum bows where you can see dimensions. I found multiple bows over 100# and 11 to 12mm wide, 16 to 16,5mm thick tips.
Heaviest was a estimate of 150# bow with 12x16,2mm tips.
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I heated one limb to 50-60 C and bend the bow over the knee. The heated limb bend easily to the brace height and the cold one remains straight. I think this is easier method to brace the bow then wrestling with it on the pegboard. And it doesn’t create that much set. I’ve used small heat medium, that’s why I heated only one limb.
Left limb immediately after bending.
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I remember the idea of not heating sal to not induce set, but i agree it doesn’t hurt the bow. At least in any sense that i have noticed my self either.
It relieves some pressure in the belly side, helping horn from delaminating. Very beneficial with heavy bows that go through tremendous stress in the horn-wood joinery.
In dry climate i have also liked swiping a little bit of water on the sinew backing before first time putting tepeliks/bracing. I noticed it helped the glue to adjust nicer, not crack at all.
Heat is great ! Set looks the same like on my first bow. First time, I heated the whole bow in hot box, but it was impossible to string, so I cover kasan eye with alum. foil.
It is braced and pretty much balanced. Tips are aligned until I pull the string Feels like 100 pounds or more. No scraping was done yet, so sal is still cca 14mm in the middle.
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Damn! You are born to be a bowyer, the shape/tiller looks spot on.
Playing with heat box sounds interesting. I wouldn’t pull the bow thought if it is at all warm.
When you are comfortable with alignment, those kasans could be narrowed more.
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Thanks This feels too easy. I made few selfbows and I hated tillering process, I believed that I don’t have an eye for it. These composites are just first time braced and they are already how I want.
Today was a bow abuse day. I heat the bow to 45C including kasan eyes, while it was braced in hot box and then I draw it to first 26, then 26 and 29 inches heating it each time. Like in kani’s description of tillering. I let it for about 10 minutes on tillering stick until it cools down. At 29 mark it was drawn only for 5 minutes, not hours, like it is in the book.
Then I heated it again but unbraced and it come slowly back to “before tillering” shape.
Bow after being draw to full draw for few minutes.
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Good that its a functioning bow. Although… the heating straightened even some of the tip reflex!
How does it look like unbraced and rested?
Do you think I damaged it ?
Unbraced shape is same like in the photo I posted 3 days ago. I think to remove the set caused by heat I must heat it and pull it back to reflex with rope.
Not in any sense that will not allow it shooting or drawing that 105#. But if you pull out reflex from wood core with heat, there is no way getting it back. Just a reminder, you can maybe see it better in person there.
There is all kind of funky dynamics happening in a hornbow, we need to remember there is sinew pulling itself to reflex. Even when the stiff materials (wood or horn) have deflex shape. Its better seen with laminted perry-reflex bows and sinew backed wood bows, but i think at some level it happens with hornbow too.
For me it’s just experimenting and looking for what composite bow can take. And it’s in the old book, so I have strong need to try it out.
One limb after heating and pulling into reflex.
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Hello guys I just discovered this new atarn version. So happy to be here. Recently I breaked 3 bows in the core. No sinew or horn glueline fail. I am wondering. When you say for example 4mm wood at midsal. Are you taking into acount the deep of grooves? I did 4mm wood in a mongol bow, grooves was 2mm deep. So at the end of the day my midsal has like 6 mm of wood from that perspective. I think maybe was too much wood so this id the reason it breaked. Wood was plain maple havesested by myself. Can you recomend me some tips?
Welcome Marc! I was just about to post some updates about bows&competitions here. Its good to have company. I want to answer you and I hope @Marek don’t mind, i’m sure he has something to add too.
I have actually struggled with the same issue as you!
Wood thickness and bending radius is a big factor, however I have discussed this with other bowyers and some are pretty certain core wood should never break if sinew backing is glued properly and has enough thickness.
However i don’t think it benefits anything to have really thick wood core, i would rather add horn to increase poundage.
Can you share some other data about the bows? Length, poundage, braced photo, resting photo etc…
6mm of wood is a bit too much, i wouldn’t use that much unless i was making really heavy bow. Maybe 6mm horn, 4mm wood would be better ratio. 60/40. It would total 8mm limb thickness without sinew.
In my own bows i had problems with bad sinew that wouldn’t soak glue well but also that sinew would break in tension. Result was sharp snapping noises and broken cores. Needless to say, this sinew must have been a problem. I harvested some moose leg sinew, which i will be using in my next set of bows.
My core failures were weird since some sections didn’t show any surface defect but core still broke underneath. I think this can be poor quality sinew snapping or sliding. Good adhesion to wood core is EVERYTHING. Thats for certain, otherwise wood core will have such high tension force that it won’t possibly survive bending.
Another thing that must not be overlooked is healthy core wood. Have you made a selfbow with your wood?
Hi Jere thanks a lot for your reply. I will keep posting my new mongol projects. Unfourtunately i do not have more photos of this bow. I just soaked it in whater to see what happened and get back the horns to do next bow.
Next months I will be trying Altam Tsogts bow with Faxinus Excelsior (Ash) core with more relaxed dimentions. 4mm horn 3 wood and 3mm sinew.
I will keep posted this projects so everybody can benefit from the experience of other bowyers.
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Cool. Ash should work just nicely. Take some photos of the bow during making and post here!
I have some late late photos of 2023 conquest cup that i could post here. Maybe there is something interesting information about flight bows, accesories and shooting.
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