horn gluing
Hi,guys
With the guide of ATARN,everything goes well with my first hornbows.With the cores,glue ,horn strips and sinew ready, I come to the step of horn and sinew gluing.
I need to know how I can make the grooves along the core and horn without a professional tool.Are the teeth of a steel saw OK?
The horn shoud go across the V joint,but how long?Is 5cm OK?
For a 130cm(core90,siyah20) bow,how thick is the sinew for 45-55 pound drawweight?My horn and core are both 5mm.Do I need press out the extra fish glue out of the sinew?
I wish to get your advice.Thank you!
With the guide of ATARN,everything goes well with my first hornbows.With the cores,glue ,horn strips and sinew ready, I come to the step of horn and sinew gluing.
I need to know how I can make the grooves along the core and horn without a professional tool.Are the teeth of a steel saw OK?
The horn shoud go across the V joint,but how long?Is 5cm OK?
For a 130cm(core90,siyah20) bow,how thick is the sinew for 45-55 pound drawweight?My horn and core are both 5mm.Do I need press out the extra fish glue out of the sinew?
I wish to get your advice.Thank you!
A friend has given the answer about the grooves.
Before gluing the horn strips ,I tried to bind them to the core with a
rope .Howerer,my C shape core became a V shape.I think that is because
the horn is much harder than the core.
My friends advised me to soften the strips with heat when gluing.I don't
know weather the horn will go back after it cools .
Can anybody give some advice?
Before gluing the horn strips ,I tried to bind them to the core with a
rope .Howerer,my C shape core became a V shape.I think that is because
the horn is much harder than the core.
My friends advised me to soften the strips with heat when gluing.I don't
know weather the horn will go back after it cools .
Can anybody give some advice?
The horn can be softened with hot air gun (or boining?). Then you can bend it to straight or whatever form. Then you clamp it. It will stay like that when it is cold.
MB bow plans call for 3-3.5 mm thickness both core and wood, but then
Some other articles say 3/5 horn and 2/5 wood is better.
I think the weight is also as dependent on curvature as material thickness and width.
I think MB bow has 5cm V splice.
What do you think about using epoxy to glue the horn to wood?
It would not create the moisture problem the hide glue does.
MB bow plans call for 3-3.5 mm thickness both core and wood, but then
Some other articles say 3/5 horn and 2/5 wood is better.
I think the weight is also as dependent on curvature as material thickness and width.
I think MB bow has 5cm V splice.
What do you think about using epoxy to glue the horn to wood?
It would not create the moisture problem the hide glue does.
jkekoni
Thank you.
You are right.When I was making wood recurve,I found the draw weight mainly depends on the thickness ;length and wideth also play an important part.A bow with a greater angle may have greater power.
The V joints of my bow are 10 cm.epoxy doesn't last for long . Some bowmakers who I know tried it ,and problems appear in 2--3 years time.In china a hornbow made in traditional way may be used for many years,some last as long as over 100 years.There is one more reason why I don't use epoxy:It is great fun to make traditional glue.I made sinew glue months ago, then bladder glue, a week ago hideglue.
I don't have a native bowyer to turn to ,because I live on a rainy highland so people here use crossbows.Months ago, I got a book about archery at hand.Unluckily,it just introduces the steps and tools . Many details are still unknown to me .
Thank you.
You are right.When I was making wood recurve,I found the draw weight mainly depends on the thickness ;length and wideth also play an important part.A bow with a greater angle may have greater power.
The V joints of my bow are 10 cm.epoxy doesn't last for long . Some bowmakers who I know tried it ,and problems appear in 2--3 years time.In china a hornbow made in traditional way may be used for many years,some last as long as over 100 years.There is one more reason why I don't use epoxy:It is great fun to make traditional glue.I made sinew glue months ago, then bladder glue, a week ago hideglue.
I don't have a native bowyer to turn to ,because I live on a rainy highland so people here use crossbows.Months ago, I got a book about archery at hand.Unluckily,it just introduces the steps and tools . Many details are still unknown to me .
Guys; take a look at this illustration, http://198.170.108.27/phpBB2/viewtopic.php?t=840 The Korean bowyer files the horn to a good flat surface to match the wood. He uses the miniature draw knife to tear fine grooves into the horn which do not match to anything- just making greater glue surface. He uses the long moon shaped object as a form under the core and places thick strip of packing, something like a thick belt over the horn. The parts are coated with many layers of glue and he heats the horn over an electric hot plate, surely not enough to cook the glue though. He ties the rope on the four layers and uses the wood winder as a lever to wind the rope. The entire group of four layers makes a rough round in cross section; this is what makes the rope work. The wooden tongs and the iron tongs are for forcing raised up places in the horn to lay down; the handles only are used. like a nut cracker. Water is added with a brush and heat is added as the process continues.
It is not so traditional but using inner tube strips is a fast and powerful method to substitute for the rope, just not as traditional. Extra winds on top of eachother can pull down anything. Leave spaces for the glue to dry. -j-
It is not so traditional but using inner tube strips is a fast and powerful method to substitute for the rope, just not as traditional. Extra winds on top of eachother can pull down anything. Leave spaces for the glue to dry. -j-
The convex shape of the belly horn is the result of gluing by using the rope technique or is done after the horn is dryed?
On hornbow.com site are some pictures with cross sections of a Korean hornbow and the horn have a moon shape, slightly concave to the side glued on the core and convex on the outside.
I wonder if the horn is flat before glueing and get this shape after that.
On hornbow.com site are some pictures with cross sections of a Korean hornbow and the horn have a moon shape, slightly concave to the side glued on the core and convex on the outside.
I wonder if the horn is flat before glueing and get this shape after that.
ginni
When Chinese bowyers cut the C shape horn strip,they will bake it over fire then stamp it with foot.
My strips are made by a friend and the surface of strips is burnt.Some bowers fry the horn strips with oil instead of fire.
I saw some flat and straight strips on Korean pictures.So they may use the same way.
When Chinese bowyers cut the C shape horn strip,they will bake it over fire then stamp it with foot.
My strips are made by a friend and the surface of strips is burnt.Some bowers fry the horn strips with oil instead of fire.
I saw some flat and straight strips on Korean pictures.So they may use the same way.
Wu,
I think is a misundertanding.
I am not refering to the overall shape of the horn, but to the the shape of the cross section of the horn.
The core have a biconvex shape of the cross section, like a lens and the horn have the proper shape to fit the shape of the core, that being concave.
The question is when is done that shape, before glueing or is made when the horn is wrapped with cord, a part of the guleing process?
I think is a misundertanding.
I am not refering to the overall shape of the horn, but to the the shape of the cross section of the horn.
The core have a biconvex shape of the cross section, like a lens and the horn have the proper shape to fit the shape of the core, that being concave.
The question is when is done that shape, before glueing or is made when the horn is wrapped with cord, a part of the guleing process?
ginni
Sorry,I misunderstood it,because I don't know what 'cross section' means.and some other words are new to me.
Do you mean how the horn can match the core when the core surface is not flat(concave)?
Sorry,I misunderstood it,because I don't know what 'cross section' means.and some other words are new to me.
Do you mean how the horn can match the core when the core surface is not flat(concave)?
Ginni; If you will go to this illustration p://www.hornbow.com/makebow2.html you will see in the upper left box a tool with two handles. This is a drawknife-like tool for cutting grooves in the finished horn strip. It appears to be flat across the edge. In the center box to the left of the broken tongs is a hand=made rasp used to flatten horn strips prior to grooving. I think it would only be possible to make a flat surface on the horn with these tools.
I do agree that there is a slight concavity on the glue surface of many of the cross-sections. How they got there I do not know, by heating, by the ageing of the sinew drawing up the previously flat surfaces, or by the stress of shooting the bow. Opinions welcome. -j-
I do agree that there is a slight concavity on the glue surface of many of the cross-sections. How they got there I do not know, by heating, by the ageing of the sinew drawing up the previously flat surfaces, or by the stress of shooting the bow. Opinions welcome. -j-
Re Making bows , arrows and stuff.
Ginni,Jack, concerning concave and convex surfaces of core and horn.
I've had the horn on one limb of my first hornbow devellop a crack about 10 cm long,right in the center along the length.I had the privilege to carefully grind the horn down to the glueline.The horn and core were flat when first glued.All I can say is that the sinew shrinks both ways in this case taking the horn with it . Probably does so on most hornbows ,the degree probably depending on the sinew thickness.Believe me,I was worried,then decided to put a new hornstrip on , scraping a proper concave into it to match the core . The bow survived and shoots very fast
Too strong for me really 80 lbs at 28". Kind of pulled something in my shoulder. Getting better now.Recovery a little slower at 70. Eppo
Ginni,Jack, concerning concave and convex surfaces of core and horn.
I've had the horn on one limb of my first hornbow devellop a crack about 10 cm long,right in the center along the length.I had the privilege to carefully grind the horn down to the glueline.The horn and core were flat when first glued.All I can say is that the sinew shrinks both ways in this case taking the horn with it . Probably does so on most hornbows ,the degree probably depending on the sinew thickness.Believe me,I was worried,then decided to put a new hornstrip on , scraping a proper concave into it to match the core . The bow survived and shoots very fast
Too strong for me really 80 lbs at 28". Kind of pulled something in my shoulder. Getting better now.Recovery a little slower at 70. Eppo
Eppo; Thanks for the post. This is why I love ATARN; because I am constantly learning something new here. I have several old broken hornbows and did notice that the horn was somewhat concave but did not realise that the sinew shrinking could also pull flat horn to a concave. One must assume that the same happens to the wood core and one wonders about the ramifications for such things as grain allignment on that fact. Bamboo would seem better suited to that treatrment considering the orientation of the inside of the bamboo to the sinew.
The poisson effect would also be contributing to the concavity.
In the youtube videos of the Korean bowyer, one can clearly see the horn glue surface is initially flat when applied. -j-
The poisson effect would also be contributing to the concavity.
In the youtube videos of the Korean bowyer, one can clearly see the horn glue surface is initially flat when applied. -j-
Yep, sinew shrinks both ways. A wood bow with sinew can be from flat to mm concave by the shrink.