44" Turkish Bow Projects

bheggeseth · Post by **bheggeseth** » Thu Nov 28, 2013 4:05 am

I thought I would share some highlights along the way as I set out to build three new bows, please jump in at any time and share your thoughts or comments.

On the previous bow build I had ordered extra hard maple. Because the maple was green the window to soak, boil, and bend the cores to shape is limited so I prepared 10 sets of core limbs. I have selected three sets of core limbs that took the heat bending real well and am ready to set out on a batch of three new bows. The bows will be 44 inches (112 cm) in length, the limbs are 5/8 inch (16 mm) thick by 1.5 inches (38mm) wide, this should leave me a lot of room to true-up the alignment.

Posted below are a few pictures of preparing the core parts for glue-up. In the first picture you can see how the limb tip is 90 degrees to the belly (bottom) side of the limb. I have built a large bench belt sander which can come in handy here, I found it works well to place the belly side of the limb on the belt sander and by eye I can sand the belly side of the limb flat to obtain limb tips that line up correctly. This is repeated again after the cores are joined.

The handle splices are 5 inches (12.7cm) in length and were cut with a bandsaw. I immediately applied 4 coats of 10% air bladder glue followed up with a generous amount of 30% glue. Only light clamping pressure was needed as the parts fit very well.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Thu Nov 28, 2013 7:58 am

Awesome posts, as always.

nokyay · Post by **nokyay** » Thu Nov 28, 2013 8:23 am

Thank you bheggeseth for this sharing.

How can you achieve perfect sal-core surfaces matching? Is there any fine tuning process?

If you immediately apply glue to the grip, the fine tuning process could be performed on sal side. Because of the sal has inner side of V shape crossection, working on sal could be more difficult than the grip side.

Can you give some details ?

bheggeseth · Post by **bheggeseth** » Thu Nov 28, 2013 1:31 pm

Nokyay, you are correct that fine tuning the sal end of the limb to achieve a good fit is much more difficult than the handle. I start with adjusting the bandsaw so it is cutting smooth, next I cut a few practice joints and then I make the final cuts. I did run a scraper over the joint to remove any burs. If the handle cuts are less than perfect you could clean these up with a belt sander, just make sure to keep the angle even and square by sanding evenly. The limbs really only get one chance, note you could start over but this would decrease the bow length slightly and you would probably want to re-cut both limbs. With care you should see gaps no more that the thickness of a sheet of paper. Note when I say immediately apply sizing glue this is after I am happy with the fit of the joint, any adjustments would take place before applying the glue. Adam notes in his book that you do not want to want too long before gluing as the wood will oxidize over time.

For my first bow attempt I had a friend who operates a furniture shop cut the splices as I was not confident I could. I am not a wood worker by trade but now over the last 4 years I have been able to clock 20 hours of bandsaw operation time. I remember very quickly becoming proficient.

The other key is to ensure the belly side of the parts are flat and 90 degrees to the tips as I described in the above post. The bandsaw will cut the joints 90 degrees to the belly side and if it is not "square" than the handle joint will add in twist.

mikekeswick · Post by **mikekeswick** » Wed Dec 04, 2013 7:30 am

Looking good!
I'll be doing the same as you this winter, this weekend i'm off out to get some core wood. First stop is where some cherry grows, if that is not fruitful then i'm going to all the woodyards around here searching.
I also intend to make 3 bows.

Arry · Post by **Arry** » Wed Dec 04, 2013 6:38 pm

My goodness, what clean cuts! Any special trick to achieve them?

mikekeswick · Post by **mikekeswick** » Wed Dec 11, 2013 1:14 pm

A well tuned bandsaw! A sharp blade that is over 6 tpi with very low set to the teeth.
Slow feed and a steady hand!

bheggeseth · Post by **bheggeseth** » Wed Dec 11, 2013 6:54 pm

Mike has summed it up very well.

I would guess that with enough practice a well tuned handsaw would produce equally precise joints. I recall seeing in Thomas's video joints being cut by hand with great ease.

mikekeswick · Post by **mikekeswick** » Fri Dec 13, 2013 8:09 am

bheggeseth wrote:Mike has summed it up very well.

I would guess that with enough practice a well tuned handsaw would produce equally precise joints. I recall seeing in Thomas's video joints being cut by hand with great ease.

Certainly with a good sharp saw and a steady eye again!
If the parts don't mesh perfectly they can also be steamed for 20 minutes, fitted together and then clamped. Wait till it's cool again and they should be perfect mating surfaces.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Fri Dec 13, 2013 1:04 pm

My first bow lost much of it's reflex due to 20min steaming (of just the cutout). Are you sure that isn't too long? Clamping the parts together looked pretty well, but just look at this:

That korean bowyer in the video has SO much routine and skill. It looks easy and effortless, but that's just like watching a virtuoso play his instrument.

mikekeswick · Post by **mikekeswick** » Sun Dec 15, 2013 8:44 am

Steam just the splice or else the heat will allow the steam bent shape of the core to relax. Use lots f tin foil to blank it off from the rest of the limb.

jkekoni · Post by **jkekoni** » Tue Dec 17, 2013 9:09 am

If you have a small bandsaw,
1. don't
2. failing one, use a blade made for soft metal like aluminium and brass cutting. Cut slowly.

If it does not fit that well. immerse the ends for an hour or so. Hammer in. Dry. Now it fits well.

NOTE: I have not done this for composite just for wooden bow, the limb curvature may pose a problem)

... a fake method would be to use epoxy suitable for wooden bows. They fill gaps like magic. YES: Hide glue does not attach on epoxy.

Gaur · Post by **Gaur** » Fri Dec 20, 2013 2:13 pm

They look nice Brad

bheggeseth · Post by **bheggeseth** » Sun Dec 13, 2015 9:37 pm

After a 2 year break I just knocked out two red oak long bows and now have picked back up this project. I look forward to seeing who is still around on this forum.

I am using the same core shape and dimensions as on my last bow which came in at 30lbs with the below dimensions.

Start of Sal: 4.5mm horn - 4mm core - 2mm sinew
End of Sal: 3mm horn - 3mm core - 2mm sinew

I would like the new bow to be 70lbs and would propose adding 1mm to the horn thickness and leave the core thickness - any suggestions?

Previous bow before sinew:

Previous bow final thickness

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mikekeswick · Post by **mikekeswick** » Tue Dec 15, 2015 8:44 am

Your plan looks good and good to see you back at it.
Personally I would be using 3mm sinew instead of 2mm but this is because all the failures i've had have been cores failing in 'finished' bows. The wood appears to still be feeling tension and so the cores have been getting cracks in them at the top of the crown in sal. I've found this after soaking the finished bows in water and disassembling.
I have a few bows on the go now and will be using 3mm sinew (measured at center of limb width in sal) just because I don't think I could handle another failure! How the Turks made 100lb+ bows with 2mm sinew.....well they must have been doing something different to me! Scientifically the 2mm should be sufficient but.....