Korean bow from Bamboo?

Alex S. wrote:

Ok, I know this sounds impossible, but I'd like to do it anyways. I am going for the exact same dimensions as the real horn bow and so I would like to ask some help about the measurements from you guys. This will be made entirely out of bamboo since sinew does not work well here at all. The siyah I will make from either mulberry or koa but not 100% sure, same for the handle.

Now for some questions:

1) How long are the siyahs? The splice length and what is the general shape of the siyahs? Are there pictures I can use or certain angle I need to achieve?

2) How long is the handle and what is the usual thickness? Does it bend?

3) Is the core the same thickness through out its length?

4) How long is the core?

I will be starting this project after Christmas and will hopefully be done by the 8th of January if not sooner, but no promises. I know because this is bamboo I am expecting set, but this is ok as long as it doesn't break. I'm sure better results can be made with sinew but that is not an option for me because of my climate, so this is manly just to prove if it is possible to make such a bow from all wood.

BTW this is my first post so hello everybody! I've been a lurker for a while and admire all your work, you people are amazing bowyers! Keep up the good work and Happy Holidays to you all! :D

I have a core in front of me, so I'll try to answer your questions.

1. The siyahs are 15" from "male" point to the other end (it will shorten after being carved). The "female" splice is about 3", with another 2" cut on down the center, for a total of 5". I have pictures of it somewhere, but I don't know where right off.

2. Uncut, the handle is about 6" long and 1/2" thick. It is made out of oak and does not bend; however, in a finished bow, there is bend right up near the handle area.

3. The core tapers from 1/4" at the siyah to 1/8" at the handle.

4. The core is about 28" from female splice tip to female splice tip.

Hope that helps.


Merry Christmas!


T

Thanks a lot Mr Duvernay!
Nice little Christmas surprise this was! :D

About the siyah, when you say it shortens, is it a lot like 15" long to 12" or just a little bit like 15" to maybe 14.5"?

Oh, so the core tapers inward? I didn't know that, I'm guessing this is so that you get the bend closer to the handle? I'll have to see the picture to get what you mean 100%, but don't sweat it, its Christmas!:D

I hope to start making the core and belly tomorrow and I'll try to take some pics through out. I was just wondering, can a siyah be made from pine/spruce? Or is it best to use hardwood? My only problem is that trees here rarely are thick enough to get siyahs from a limb so I was wondering if pine/spruce would be strong enough? Or can it be laminated?

Merry Christmas to you too and to all on here!

eh, change of plans mates. :oops:
Bamboo backing isn't going so well and proves to be quite difficult for tillering. So plan B: Use sinew instead. I know it don't work well here because of the humidity but I'm gonna try it anyways, eventually I will move somewhere drier where I can use it so its not total failure. :wink:

Will try to post pictures of the materials and so on as soon as possible.

Alex; The big surprise is that a composite bow can be shaped by heating and bending just like a self bow. Use direct heat, go slowly to make sure that the core is also well heated. What bamboo are you using for backing and what is the core made from? -j-

Really?!! Thought that would be damaging to a composite bow, guess not. :) Bamboo seems to be moso or similar type from mainland Japan, but not 100% sure, very good quality however. Core is same material. Only problem is, I cannot use heat on this bow because of artificial glue used to glue it up, no worries, I made extra materials because I knew something would go wrong. This time I use sinew as backing as it is more controllable than bamboo backing. After I get this one made, I'll attempt the all bamboo version again. :)

-Alex

OK, I have been having some problems with my hide glue. It seems that it is drying faster than I can put my core on the belly piece. I am able to get one limb wrapped but when I go to wrap the other limb the glue has already dried to a rubber state and so I am unable to glue it. Some questions come to mind now:

1. Can I heat the bow to melt the glue while its clamped so it glues together?
2. I am using one piece of bamboo as the belly, should I cut it in two and glue each limb separately?
3. Is my glue drying too fast because its too thick? I tried thinner but it doesn't seem to glue as well as when its a bit thicker....
I will see if I can get pics of the bow tonight and post them to show progress.

How hot is the room you are sinewing in ? A warm damp work area will give you more time . Put a tea pot on and use the steam to warm the parts ,if needed . Or make someone help you ,four hands is faster than two.

This is one reason , why old asian bowyers use fish glue ( mix with hide or sinew glue) Fish glue give you more working time .

Alex; The hide glue is put on in many layers starting with very thin and working up to thicker. At last when the glue is built up on both surfaces, once again slather on watery glue and heat the parts to be joined over direct heat. The entire glue mass will become tacky at once.

Of course you can go back and add more heat as you assemble, and WATER by brush to the edge. Capillary action draws the water onto the inner surface.

My favorite binding medium is inner tube strips. By working carefully you can even heat after the entire binding. Don't over do it. The glue will squeeze out between the tube windings as you warm the glue=up.

All this might be practiced on scrap pieces before proceeding to get a feel for timing.

I heard the fish glue story but have not noticed a great difference. It may work better for others, though. This gluing is a complex mix of temperature, moisture and timing. Weather affects the mix too. -j-

Yej, Jack- temperature , moisture and timing is VERY importent , but 20 or 30 min. + is very interesting time too. and this is gift from fish (and i mean not only crocker glue but mostly orig. sturgeon air blader glue )This is not only "one man talk to me".I have this glue and this is experience. Flexible and power is another qualities .Worse fact is his hydroscopic level.

Thanks guys for the tips!
I will practice more on the timing and method on scraps as you have suggested before I do it for my bow. The next will be glued using only hide glue but the current one I'm making, because limited experience atm I went with TB2...not traditional but all the other joints and stuff were glued using hide glue. When I get more time I will show my progress.

One Korean bowyer here has just developed a laminated bamboo bow. It is very much like the Hwarang, but the belly is bamboo. Here are a few pics. For more detail, you can use the image URL, but omit the "b" in the file names.

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That's a beautiful looking bow, do you know how it performs?

I was going to try it out yesterday, but when I got to our "traditional house", I found my wife's dog dead--it kind of put a damper on things...

The bowyer says it shoots very smoothly. I'll give it a try tomorrow, as I have an archery class to teach here at the university then.


T

Wow! :o Your too kind Thomas to be posting all this, thanks a lot! Those pictures you posted are awesome and will really help me on this bow. :D The bow is fantastic BTW, very well crafted. I was wondering though, in the picture the bow does not have full circle unbraced shape. Is this because of set or was it made like this?

If you have the time, I would really appreciate it if you can report on its shooting/handling characteristics. Thanks!

This is a very nice bow!
Is made all by bamboo, or is like a hornbow, sinewed on the back?

The bow is a laminated bow, just like the Hwarang, with the exception the belly is bamboo. It has a bamboo core and carbon lams. I just shot it today for the first time--it shot very smooth and quick.


T

I took a few more pictures today; this time it was at our Korean traditional house. I am titling these Traditionally Korean

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Also, here is one of me shooting it yesterday in the first traditional archery class I taught at our university:

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This bow is traditionally made without carbon lams.

It works pretty well made of 2 well choiced slats of bamboo, glued with hide or fish-glue. You can insert a piece of wood(mulberry) as a grip in the center, use a lighter wood like walnut for the attached siyahs.
It is very, very important to ground the bamboo with several layers of a thin solution of hideglue, cause bamboo- fibers are hard.
For to shape the bamboo, use direct heat at the inside of the boo, otherwise the outer fibers will break.

For a simpler version of this bow, take 1 bamboo-slat with its outside as the belly, attach a grip and the siyahs and sinewback it.

I like this design very much, it is very well sophisticated with a smooth draw and great speed.

Michael

Michael,

Do you have pictures?


T

Thomas,

I?ve done one of these sinew- backed bamboo- bows for a customer who wants it as a short bow for horseback archery. I?ve to check for a pic the next days.

I don?t think that this version of the Korean bamboo bow is really traditonal but it is a nice possibiliy.

I?ve done the bamboo- bamboo version too, but it is so hard to draw, maybe more than 100lbs, nobody likes this bow to shot.
I?ll take a pic.

Michael

Thanks for the pictures Thomas! :D
How does it shoot compared to the hwarang? The bamboo belly seems to handle the compression stresses quite well from that last picture.

Redhawk,
I need to try a bamboo-bamboo version like this, seems like it would work very well if the tiller was right first time around or close. Also, a bow like this could be made relatively fast and cheap! :shock: hmm I see what I can do, maybe make some like this while my other's sinew backing dries....

Alex,

I haven't chronoed the bow, yet, but I plan to. Just from my feel of it, though, it is surprisingly similar to the Hwarang. There's probably a touch less cast than the Hwarang, but nothing major.


T

Great news Thomas! Sounds like a nice bow!
One question:
How wide is it at the tip shoulders? 3/4"?

BTW will have some pics tomorrow of my bow :D (finally..)

Hello everyone!
I have finally got some pictures of my bow and hope they will be helpful in someway, if not, maybe entertaining. :D

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Made some mistakes such as putting the handle under the core and not adding enough bend in the handle and siyahs but it should work. There is only one sinew layer on at the moment.

Alex, your bow looks well crafted.

I would like the other ATARNOS to document their working progress like you.

Tell us the drawweight of your bow, my experience with this design is that these bow are very hard and heavy, almost impossible to shoot. Such a bow has to be heated before the drawing.

Michael

My belly lamination is not very thick, actually its quite thin and the next I will make thicker. This bow seems like 40-50 pounds, but I'm sure if I left it thicker it most definitely would have been very heavy. Yet, I have still not added the finally sinew layer and so this weight might go up considerably....

Nice work. I have been meaning to make a bow like this for some time, please let us know how it worked. I actually made a small a la Scythian bow in this configuration, but the core was hardwood, only the belly was bamboo. It worked fine and I was amazed how much strain the bamboo belly could take with no trouble. From my observations, horn on the belly is more resilient than bamboo, so hornbows do not take so much set.

Good luck

Adam

Hi. .. the bow looks realy nice...i have a fiew questions for you iff you dont mind...
1. how long is the bamboo core..?
2. the core is bamboo flooring or raw bamboo like the one used for the belly
3.I did not understand from the pictures how did you made the syiahs...looks pretty long...
Thks a lot...and sorry for all this questions,,,

The core is 66 cm long
Core is raw bamboo with skin side down.
Siyahs are 37.5 cm long, 7.6 cm splice. I made them by boiling for 40 minutes each and then bending over a form.

I'm sorry to say, but this bow has failed....
Bamboo wasnt the problem but the glue joint was not sufficient enough,
thus the bamboo lifted and crushed.
This happened in the handle and on the lower limb.
All other parts remained undamaged and so I guess it was just the glue.

I was wondering, would there be an advantage to using two separate pieces,
like as if using horn?

Alex


BTW The core and sinew is still safe, as are the siyahs.
I managed to remove the handle and belly without harming the bow.
Maybe I might try to remake it, other wise I will be starting a new one
shortly...

Hmm....thks for your replay....i think that maybe the core wass to short...and you put that ash handle in the middle, and i think that the handle area wass to stiff maybe....and i see that you put that knot of the bamboo right in the middle, and i know that this is not so good....you should avoid to put the knot from the bamboo right in the middle.... im sorry to repeat my self...but i realy think that the bow wass to short, and the relfex wass realy sever, so i dont know....i wass asking you aboute the bow becose i would realy want to try to make one of my self....i dont have acces to horn so i have seen bow like that made only from bamboo...but i must say that im a little afraid... :D ...i dont know how bamboo will perform and iff it will keep it together to such a sever reflexed bow...i have seen something in this style made with birch core, bamboo strip for the belly...but the design wass not so sever relfex...and the syiah wass much shorter thenn this ....and not so much relfex....and i think it wass a little longer....and it hold it together....i realy dont know whatt to say....im not an expert an asiatic bows...im still trying to read as much as i can , and im trying to learn...but i realy want to make a bow like that, only from bamboo....do you have some pictures with the bow broken??? im curiose to see how it broke and from where exactly....iff its posibile...thks a lot....

Core was same size as the normal Korean bow, so it wasn't too short.
The ash handle was a mistake, not enough thickness and bad place to
put it. I think if it was on the back and thicker like original, the bamboo would
not have lifted in the handle. The ash handle bent straight when I braced the bow! :shock:
The other limb fracture was cause by bad glue joint, I use too much
pressure and glue got drained I believe....

I don't see why node in handle would be bad if on the belly side, but in core this would be not acceptable. I have made bamboo bows before with such reflex, but they bent through handle and were lighter poundage. I think bamboo is more than strong enough for the belly, just need to have a good glue joint. For less severe designs such as Mongolian or Hungarian, you shouldn't have too much problems.

I will try to find the remains or the belly, I'm not sure where I put it,but if I find it I will post pictures.

Thks Alex..for your replays...im asking all this things becose i would realy want to try om make a bow like that....im doinga lot of reaserch right now...but pretty soon i will start working on a similar bow....im thinking ...how could you put that handle on the back of the bow..?this means that the back should be flat on the handle area right??

Yes, the back is already flat from when you make the core. Later you can round the edges to let the handle blend into the core better, also this makes it easier to lay the sinew on smoothly. Good luck, looking forward to seeing your work.

Hi alex....im sorry to ask you this again but i just dont understand...whenn i look at your pictures i see 2 strips of bamboo glued together, and the handle in between this to strips...right?? so this mean that the belly strip is with the skin face down....and the core????how did you make it?? did you make it perfect flat on bouth sides????this the thing that i dont understand....i know how is it with the belly thing...i have to temper her...but i dont understand that part with the core...im sorry..

The belly is skin down, as you already said and is heat treated.
The core is also skin down, I make the skin side perfectly flat, but
because I put handle inbetween the core and belly I didnt flatten the
other side. It is also not tempered, maybe I will for the next and see
if I get better results.

The next one I make I will flatten both sides of the core so I can glue
the handle to the back of the core. I think this way will work better,
but I still need to test to see.

Alex

I remember Jaap K told me last time in Korea, building a both-side laminted bamboo (---) bow, it is essential, the bamboo is tempered AND how and where the internodias (#) of the belly which absorbs the stress during compression (draw) are placed:


Example:
Bamboo back side: #-------------#------------------#----------------#--
Grip: =======
Bamboo belly side: ----------#---------------#--------------#--------------



Check hou Yumis are built and the internodia.

R