Bj?rn's Turkish bow and also some arrows

Bede · Post by **Bede** » Thu Nov 20, 2014 11:36 pm

I think that there are three main shapes for this style of fletching. I categorise them as long, medium and short. If you look at them as have three sections of the profile: the rounded rear edge near the nock, the parallel section next to this, and the taper down to the arrow shaft at front of the fletching. The Dresden arrows and those from Kassel have the middle parallel section extended to deal with the necessity of having a heavy war arrow straighten out quickly while still keeping a low profile. The puta arrows from the Askeri Museum are full length and have medium length feathers. Some of the azmayish arrows in the Grayson Collection have very low fletching with now parallel middle section. The major difference between the types of arrows and their fletching profiles is related to the distance at which they were meant to be used. War arrows have to work at short to medium range, long puta arrows have to act at medium range and short puta arrows have to act at long range. Azmayish arrows act at extreme range.

In the case of war arrows, shooting is done under extreme conditions. Drawing and aiming have to be done quickly and precisely, just as in hunting. In target shooting, there is a greater chance of a perfect release and less fletching can be used to obtain higher speed and a lower trajectory. More time is also possible for aiming. At greater ranges than the admittedly long Turkish target ranges, shooting is closer to flight shooting so that the fletching is reduced even further.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Sat Nov 22, 2014 10:28 am

The ones from the Askeri Museum also seem to have longer fletching (something like 1:5 or 1:6 if we take the distortion into account) and the shaft is tapered at the foot.

While my other pic is not very sharp, it's closer to 90? and allows to judge ratios. In these arrows, the ratio of fletching to shaft is 1:10, which would match the description from the book. ~ 6,5cm fletching for 65cm arrows. The shafts also have no or at least a very small taper at the foot.

I'm a bit puzzled. Maybe the sets are from different periods and I'm wrong to assume that everything was standardized.

Bede · Post by **Bede** » Tue Nov 25, 2014 12:11 am

I would not be surprised if individual designs were adjusted to particular pieces of wood. As well, skilled archers could find that certain profiles were more suited to their techniques.

As to the lack of taper at the foot in some arrows, think that this is almost entirely a perspective effect for the photographs. War arrows definitely are thicker at the foot to prevent splitting on impact. Pishrev and azmayish arrows are exceptionally narrow in the last section of the foot. Puta arrows are less so.

I think we sometimes underestimate the difficulty of maintaining a constant size for something like arrows or bows over a large area like the Ottoman state. The methods of disseminating a pattern for a standard size and profile are restricted in societies where printing and centralisation are not widespread. For the army, contractors were undoubtedly supplied with a standard requirement and this would have influenced other production. The physical requirements of competition and the prestige of the capital would also encourage uniformity, but we don't have samples from every workshop to make statistical comparisons. Instead we have groups of arrows randomly surviving and that is all we have to go on. If a set of arrows from a particular individual survive together, this would skew any assessment of standardisation because of their uniformity.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Fri Jan 23, 2015 11:01 am

Final layer done, this is already 2 weeks into drying. The ugly surplus bunch of sinew that I had to leave on the grip will be filed down soon and there's some minor other work that needs to be adressed.

The right limb seems to have a weak spot near the grip. I took off 0,1mm thickness too much in the shaping I think.

Long backstrap wasn't ideal for this type of core, it proved very hard to control as it reached the kasan. It literally flowed over the edges and crossed fibers underneath that seemed to rise strangely from this section, so that I had to hold it down on both sections until it was gelled firmly.

I tried the korean method with the gelled strips on another bow, and it was quite the contrary. Very easy and reliable. No crossed fibers or problems at all. Everything kept completely straight as you comb it out. Although it's hard to judge if the bundles are saturated enough. This method might be more beginner friendly with long sinew bundles like I used (+50cm). It's really extremely hard to transfer the long and slippery bundes to the core without anything dodgy happening, if they're gelled on the other hand...

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Mon Apr 27, 2015 7:55 pm

I've started to open the bow. It had a little propeller twist, but that was fixed with light heat.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Tue May 12, 2015 5:59 pm

I'm going slow. Too much other stuff to do. The worst twist was fixed. It's still not completely aligned, but we'll get there.

I also cooked some glue from Tiger's yellow croaker bladders.

We'll see how it works.

Tapsnap · Post by **Tapsnap** » Thu May 14, 2015 3:35 pm

Tell us what you think of the croaker bladder glue and how you are preparing it.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Sun May 17, 2015 7:01 pm

The bladders are from the Small yellow croaker (Larimichthys polyactis), or 小黄鱼

The first batch was soaked for 24h, cut to small pieces with scissors, run through a blender and then "cooked" in a bain maire setup for at least 12 hours at around 45-50?C. I added more water than the recommended 5x the dry weight. The result was 50g glue from 100g dry bladders. It took about 4-6 days to dry completely

The 2nd batch that's currently drying was soaked for 48h and I'd recommend paying attention to hygiene, like when cooking jam. There was some slight odor after the 48h. The bladders were cut with scissors, but then I heated them in a pot with 5x the dry weight water up to 60?C for at least 10mins. Blending afterwards was alot easier. The rest of the process was like above. I suspect a higher yield in this one, but we'll see in the next days.

The current temperature isn't good for drying this glue as I found out (28?C peak outside a few days ago, inside about 20). If it would be hotter, the glue would have problems gelling and most likely start to foul. It seems that it's melting temperature is somewhat lower than hideglue. At around 21?C it had trouble gelling, which you can read below.

Which leads to the "test" that I prepared. Like Markus wrote in his thread about cooking glue from sturgeon bladders, I glued up some maple leftovers from bow laths with hideglue and yellow croaker glue each. After a week I'll try to break them apart by hammer and see if the glueline fails.

Temperature in the room was 21,7?C at 34% relative humidity. I took 2g glue with 6g water each and melted each in a pot that was placed in the same bain marie.

Melting the glue, the croaker glue dissolved faster, it was completely liquid 10mins before the granulated hideglue.

The hideglue was visibly more viscose than the croaker glue (which also seemed to strangely trap bubbles of air quite easily) at the same concentration and temperature.

Both glues were applied to the wood with 2 wooden applicators.

After that I put 2 drops each on plastic foil to see how fast they gel. Not exactly visible on the pics, but the drops are about the same size.

Hideglue:

Yellow croaker glue:

The hideglue took about 1m50s to gel and was completely gelled, so that it wouldn't stick to the toothpick anymore, at around 2m40s

The yellow croaker glue had problems gelling at all at this temperature. It was a solid gel that wouldn't stick to the toothpick at around 5m20s.

The gel strenght was also noticably different. The hideglue was quite solid, but it seems the yellow croaker glue had problems gelling at this temperature.

I put the foil and the glasses with the glue into the fridge (~4?C) for about 15mins and the cold seems to have helped gelling. After taking them out and prodding both with a toothpick, I couldn't detect any differences. Mind you, those are all the results that I could get without any special equipment and are somewhat improvised.

Reason for comparing hideglue with yellow croaker glue was, that some people have told me that they couldn't detect any differences, especially concerning the time that the YC glue took to gel. Maybe you guys worked with lower temperatures in your room or you didn't notice that the temperature was lower on one day when you used YC.

We'll see about the quality of my glue when I'll try to break the test pieces apart, but so far it seems that YC glue gels slower at the temperature that I had in the room. If you consider working with it, you need to take it out in the cold afterwards, or it won't gel properly and the bond will most likely be poor. I have read quite a few times that the old bowyers did their sinew jobs in the cold season, which makes perfect sense.

You can read more precise info in "Schellmann (2007): Animal glues: a review of their key properties relevant to conservation."

Kviljo asked me to check how the flexibility of both glues compares, I'll try to figure out a way of how to make a slip of dry glue of about the same thickness.

It would also be interesting to compare it to sturgeon bladder glue, maybe I can do that if I find time. Anyway, Adam already wrote about it in his book and I don't think I have much to add.

Interesting sidenote: I spoke to Wen Cheh Huang about it, and he told me that he uses bladders from Miichthys miiuy for his bows. For us in Europe, it wouldn't make much sense, as they're more expensive (70$ per 100g) than sturgeon bladders. Bladders from the large yellow croaker also come to mind, but they're equally expensive. It seems that sturgeon is the best and cheapest material, unless you use hideglue and a super hot and humid room.

PAZUZU · Post by **PAZUZU** » Tue May 19, 2015 9:09 pm

oh man! If you know you want to do experiments, I sent you an extra amount of glue. I hope next time. thanks for sharing.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Wed May 20, 2015 5:05 am

That's nice. I always asked myself what kind of form you use to dry the glue in?

PAZUZU · Post by **PAZUZU** » Wed May 20, 2015 8:50 pm

if I prepare larger amounts of glue use this form - like sticks

if I cook small amounts of dry glue in the form of a thin film.

This form is very good in case you need to thicken rarely glue. just add a few pieces of dry glue directly into a hot rare glue

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Fri May 22, 2015 9:59 am

Ah great. That's a good idea. My glue was always too thin.

Markus · Post by **Markus** » Tue Jun 02, 2015 2:14 pm

Most interesting and thanks for sharing. Have you tried to break apart the test pieces yet? Markus.

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Wed Jun 03, 2015 6:32 am

Yes. The first ones that I prepared weren't sized with thin glue and thus the glueline broke clean in both. It looked like the glue was too thick, there wasn't enough in the scoring to hold properly. Kind of obvious from the start

Bj?rn Sofeit · Post by **Bj?rn Sofeit** » Fri Jun 05, 2015 1:06 pm

I need some more containers and time to try the experiment with sizing the pieces thoroughly.

In the meantime, here's the sturgeon air bladder glue that I made from Pazuzu's bladders.

Soaked and pounded to dough

The whole process of extraction took about an hour at 50?C

Filtered and put in the fridge for 20mins

The gel was strong and it was easy to cut it up. Note to self, smaller strips next time.

The yield was 95,1g dry glue from 114,3g dry bladders. The solid residue in the fabric was about 2g. Most of the difference that was lost was indeed glue that got lost in the fabric or on my hands. Given the right equipment to filter, I'd suppose yield over 95% is no problem to archieve.

If we look at the extraction time and yield, I'm not sure if there's anything better than these sturgeon bladders.