Primitive Archer
Main Discussion Area => Horn Bows => Topic started by: superdav95 on February 19, 2022, 12:18:53 am
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Hello all horn bow enthusiasts and aficionados… I just sinewed up a molle bow and waiting fir it to dry so I figured out this fish glue to good use with a tartar style horn bow build. I have the horn, sinew and maple and bamboo for the core build. I decided to go with bamboo as I had it somewhat ready to heat bend into shape and bent it around an empty 20 lbs propane tank for shape. That’s the nice thing about bamboo it’s pretty forgiving with heat. I didn’t need to soak it prior to bending. I Matched each limb to same bend and then cut v notches for the tips/Kansans and also v notches for the handle section. I went with 3” v on the tips/siyahs and 4”v on the handle. I used some spare Maple for the handle and siyahs. The sinew I’m gonna use for this one is gonna be moose blackstrap and the horn is Buffalo. The limbs are 22” bamboo heat bent. The siyahs are approx 7-8” long. Handle section will likley be around 10” long which I’ll make a 4” v male notch one each end.
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Funny you should post this....I'm just getting the parts together for a Crimean Tartar bow as well! Good luck with yours! It is looking good so far!
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Thanks man. Ya that’s funny. I’ve always wanted to try one. And love the larger size comparatively to other styles of horn bows. I’m thinking it’s gonna be a nice challenge for me anyway and checks a lot of my boxes. Good luck with yours although I’m sure you’ll be fine as this will be old hat for you. Using the fish glue on this one too so I’m glad I took the time to make it.
Cheers.
Here’s a few pics of the core glued up…
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The only thing I would mention is with the thin sals it is difficult to glue the horn on without inducing twist. If I were you I would glue some lams on the back of the sals to stiffen them. As a rule my working limbs will be 15mm thick when gluing horn on.
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Ya it’s gonna be a challenge for sure. I’m gonna have to make a curve piece of wood matched for each limb to have something stiffer to keep in place for glue up of horn. It was bamboo I had already thinned down and so I decided to go with it. I’m realizing this will be a challenging bow in many ways but should be fun regardless even if it explodes! All investments of learning I guess.
Thanks again.
Cheers.
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Update. Just glued up the horn today. It took a couple hours make my jig and organize my set up to make glue up go as planned but I got good squeeze out and I think it’s good. I made a 10 teeth per inch grooving tool out of an old scraper which worked fine. I did the grooving of horn and wood core yesterday and smoothed out the grooves to clean em up a bit. Nice and deep. Approx 2mm. The horn is fairly thick so I’ll have to remove some later but figured it would be easier to clamp down while thick. I should have kept the bamboo thicker prior to glue up and that would have helped me out for sure but the jig worked well regardless.
Thanks for looking…
Cheers. Here are few pics
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More pics
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great to see it progressing :)
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Few pics after glue up and removing from form.
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Horn is pretty thick so I have some removal to do but glue up looks good. Time will tell if it holds up. Gonna let it sit couple days then start on it again.
Thanks for looking!
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Update on this tartar bow…. I put the first layer of sinew on tonight. Followed Adams book instructions as best as I could interpret. Measured the bundles and then split those in two separate bundles for the first course. Did the first layer covering the bending section of the limbs then overlapped on the handle section. Will let this gel and firm up over over night then string it in to a little more reflex. I’m gonna do as Adam suggests and lay 80grams so 40grams per side. Gonna do three layers or courses of sinew letting each dry 2 weeks in between. So far the wood core is just a hair over 1/8” thick. The horn is rounded a little more to do later but is slightly thicker then core but pretty close. My aim is to have wood, horn and sinew all about same thickness in the end. For the grooving on the top of wood core I found what I consider to be the perfect solution. A jigsaw blade for laminate wood 20tpi. The teeth were perfect and straight triangles as opposed to others I saw. Happened to see these at Home Depot and figured why not try it. It worked very well. Flawlessly actually. Super sharp and very easy to get started straight by hand. Not that it super critical I guess but nonetheless I’m gonna use the courser 14tpi blade in this set to do the horn grooves in my next horn bow. Gonna make a tool handle to hold the blade. The nice thing about these is that they come already super sharp and ready to go. I made my own groover with a file and lots of patients but would have had straighter lines with one of these little blades I think.
Here’s a few update pics.
Thanks for looking. Cheers
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So after about 6 days of letting first layer dry I’ve developed a slight more reflex curve on the right side. Is this something I need to worry about or tend to. Meaning should I scrape some horn off the opposite side to match the curves. Let me know what you all think. Maybe I’m overthinking it and just deal with it when I tiller. I’d be interested to know what you think.
Cheers
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This is normally an inconsistancy in the core. Leave it alone until time to tiller!
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This is normally an inconsistancy in the core. Leave it alone until time to tiller!
Roger that. I’ll let her go then. Could it also be the inconsistency in horn? I remember when I glued the horn on one piece had more curve in it then the other when sizing. Either way one more week till next layer. Thanks for the input.
Cheers
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the core is the stiffest part and is what gives the bow its shape.
Horn strips are normally easy to make the same thickness/taper.
Did you heat the horns before glue-up? Ideally they should be at 50 degs and therefore soft enough to conform to the core. Horn has quite a bit less stiffness than the core.
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Yes. I did heat up the horn with a radiant space heater prior to glue and sizing. The core of bow the same. My core was pretty thin if you remember and so when the horn was put on it was slightly thicker then the core actually in some place until I did some scraping and filing. This bow will be a 50lbs draw weight bow or under when done I suspect. After a few more days of drying it’s a little better shape now. Gonna do a second layer this week on it and see where we end up when it dries. Again thanks for the input.
Dave
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Second layer done! That’s a total of 63grams so far. Last layer will be in couple weeks. That final layer will be about 20grams bringing my total to around just over 80grams. Attached is a pic from Adams book of how I’m layering out the sinew fyi. Hope it works out. Thanks for looking and for the feedback
Cheers
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Well there bad news and good news. The sinew on this bow failed. Or more appropriate I failed to lay the sinew properly on this particular bow. I used 10% glue solution when sizing the freshly grooved back of the wood core but I think I must have starved the glue and was little too light on the glue and had starved the core and sinew of glue. You can see where it lifted in the middle of each limb. The good news is that I may still be able to salvage the core and horn as it remained intact. I was able to pull off the sinew in one layer with some effort and even save the sinew. The silver lining too is that the sinew came off in one piece and Undamaged as far as I can tell. My initial thinking was to put first two layers on as just top layers and not overlap around the core onto a little bit of the edge of the horn. I was then gonna use the third layer to wrap around core onto the horn for final layer then cover with thin rawhide. I never got that far unfortunately or fortunately depending how I look at it cause a failure at this stave is better then having it fail after drying time after third layer I guess. Glass half full. I wonder if I should have wrapped the first two layers also or if this would have made a difference in the end. It may be a number of things that caused the sinew to pull away. When pulling off the remaining sinew I noticed that parts of the limbs seemed dry and as if no glue at all. Other parts the wood pulled off with the sinew. I remember heating up the core wood prior to sizing with glue. I wonder if I did not have enough layers of glue or that I didn’t use a strong enough concentration of glue when sizing. I weighted the glue to about 10%. Then used 20-30% for sinew laying. I used straight sturgeon glue not mixed with hide glue. In Adams book he mentions the mixing amounts of hide and bladder glue for the sinew. I would love to hear what you guys think about this and where I may have gone wrong. Thanks in advance.
Going to try and salvage my core and try again.
Cheers
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Morethan likely the sizing wasn't sufficent on the core.
the safest way to size is to use very thin glue, like 5%. Even if it is only for the first few coats. The thin glue really 'gets into' the core. Same when gluing horn. The importance of sizing can be overlooked.
My hornbow failures in the beginning were mainly sinew lifting off the core. After the 3rd bow doing this I contacted Adam Karpowzi and asked his advise. Very thin glue for the sizing and 30% for the first layer of sinew. I followed his advise and haven't had a failure since. Often these things are only subtle....but these bows present a steep learning curve!
Could you show a picture of the core where sinew lifted.
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Morethan likely the sizing wasn't sufficent on the core.
the safest way to size is to use very thin glue, like 5%. Even if it is only for the first few coats. The thin glue really 'gets into' the core. Same when gluing horn. The importance of sizing can be overlooked.
My hornbow failures in the beginning were mainly sinew lifting off the core. After the 3rd bow doing this I contacted Adam Karpowzi and asked his advise. Very thin glue for the sizing and 30% for the first layer of sinew. I followed his advise and haven't had a failure since. Often these things are only subtle....but these bows present a steep learning curve!
Could you show a picture of the core where sinew lifted.
Ok. That makes sense actually. Thanks for your input. In the pics it looks pretty dry looking to me I made sure the grooves were good and clean and warmed up the core before sizing a number of times. 3-4 times. I’ll try and use the method you suggest when I reapply the sinew. I reread Adams portion of the book and he mentions too that it should wrap around the core and around onto the horn and bit too. I didn’t do that with first two layers and wonder if that was part of problem too. Here’s a few pics of core after pulling sinew off. In the mean time I was able to salvage the sinew cleaned it all and separated it all and weighed it all again.
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No the wraPPING ONTO THE SIDES WASN'T THE PROBLEM. tHIS STEP ISN'T TO KEEP THE SINEW FROM LIFTING IT IS MORE TO DO WITH ADDING SOME PROTECTION TO THE EDGES OF THE LIMB.
Ooopps caps lock.....:)
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No the wraPPING ONTO THE SIDES WASN'T THE PROBLEM. tHIS STEP ISN'T TO KEEP THE SINEW FROM LIFTING IT IS MORE TO DO WITH ADDING SOME PROTECTION TO THE EDGES OF THE LIMB.
Ooopps caps lock.....:)
Ok good thanks for the help. Will post updates once I get to reapply the sinew to this bow.
Cheers
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Ok so for all you horn bow guys out there. I’m giving another go at the horn bow after taking a break from it. I resized everything after a goo clean up and inspection of core. All seems good but I’m worried about it lifting again. I put several sizing coats and made sure all was nice a shiny and saturated into the core. I put my first layer on and get a close eye on it over the next few days. I noticed that it was wanting to lift off again. So I decided to wrap it with some bandage and then rubber inner tube. Seemed to be better but wondering wha the I’m doing wrong. I back strung bow into a heavy c shape prior to laying of sinew could this be it. I read through Adams book again to find the answer but came up with nothing. My guess is that the sinew is drying and shrinking lengthwise and pulling off in the mid limb area. The first layer was 30 grams and am following the sequence laid out in Adams book. Did I pull it into a c shape too soon. ? Should I have waited until it dried a bit then pull into c? In one of the pics here there is a small grain run off or inclusions at the edge. Is this a concern? Also the shape is an uneven c shape with one side more bend then the other. Should I correct this now with slight heat? Let me know what you guys think. Here’s a few pics. Thanks for looking
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Hello,
I have done only one horn bow ... so I am not a profesional ,... but my bow is after 2year still in one piece :D
I guess ... maybe the problem is in gluing
I put over 10 coats of very thin fish glue, ... and did heating gently with a heat gun all the time.
I put the sinew layer in korean style (combed sinew) .... before I put this on the bow I wet the layer with water and heated the combed layer with heat gun gently .... did gently wet-ing of the layer (on the bow) with water and heating, heating and wet-ing with fingers.
When sinew layer get gelled I put a elastic bandage over the whole limb gently tightening.... then did heating again to get glue in liquid state and gently squezed the glue into bandage...
After hour or so,... gently remove the bandage,.... then I wraped the limb very tight with old bike tube, slighty overlaping and ... and did heating againg.... to get all the excess glue out...
After each layer I shortened a rope to bend it into more C shape.
I did the the same with all 3 sinew layers... I slightly sanded the dried sinew before sizing of course
Till now bow still holds.. :OK
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Thanks for responding to my question on this build. Sounds like I did mine very similar to the way you did which is possibly good news as your held fine. Time will see I’ve got one more layer to do so fingers crossed. Thanks