Glues

I suggest that you should be able to use hide glue for gluing wood or horn components. But for sinew, the melting point for hide glue is too high, so I recommend fish glue there.

Stephen,

I have to disagree here about hide glue versus fish glue. In another post, you mention that the glue should not burn the fingers or it is too hot. This also applies to hide glue. The hide glue should be used at around 45 degrees celsius for sinew. If the sinew is melting, the hide glue is too hot. If the sinew starts to curl up, the glue is too hot.

Hide glue can be used for sinewing the back of the bow. It has been done for centuries in North America.

The glue is created at a higher temperature but it is not used at that temperature.

Jim Welch

I have very good hide glue and use it for all. It is very light color. I works quite nicely. It is also cheap here.

But I recently got a message, that they are stopping to produce it. Not much people uses it these days - bowmakers, fashion designers, antique furniture restaurators....not big market indeed.....

I bought some stock, it has some shelf life....

Jim: agreed. The temperature is the key issue. If you can apply the hide glue at a reasonable temperature and the glue would not be either too thin or too viscous, then it would be fine.

I should like to add that it is sometimes assumed that the glue is no more than an auxillary compnent in a hornbow. However, I believe that a substantial part of the working structure of the limb of a bow is served by hardened glue associated with the wooden core and the sinew. (Less so with the horn, which is not much penetrated by the glue.)

It follows from this observation that thinness (i.e. excess water) would be a serious flaw in the construction. Excessive viscosity prevents pentration of the glue into the wood/bamboo of the core and would also be a flaw. Achieving the correct balance here is what the craft of the bowyer is about. Three different qualities of glue may be needed to deal properly with these issues when gluing wood to wood, wood to horn or wood to sinew.

S.

hi,

I use hide glue which I get from an art supply guy in germany. its quite expensive. he sells one small bar of about 40g for 4-5 euros. but its good quality.

I always let it soak for about one day in cold water. the excess water I pour off and warm the rest in a bain-marie, never on direct flame. actually I just fill the sink with hot water and let the pot with glue float in it.

I used the same consistency for glueing togehter the wooden core and the syiahs and also for sinewing.

I agree that if the water is too hot the sinew will curl and turn white.

so which are the right consistencies for applying the glue and the horn and for glueing together the wooden core Stephen?

stefan

So which are the right consistencies for applying the glue and the horn and for glueing together the wooden core Stephen?

Here I can't help. This area is the area where traditional bowyers guarded their secrets most closely. Klopsteg might help.

However, you should pre-glue ('size') all wooden components before gluing. It is vital that the glue penetrate the structure of the wood to the greatest extent possible. As the aim is penetration of a single compnent, higher heat and thinner consistency should be possible. I hope that Adam Karpowicz will give us some insights.

Stephen is correct in saying the glue must penetrate the components to the greatest possible extent. This is why the Koreans used many coats of very thin glue over horn. The heat and/or low concentration makes the glue less viscous for best results.

Wood is easier to glue than horn, but still good preparation is essential. It is a common mistake to "roughen" the wood for gluing, by sanding or rasping. This creates fuzzy surface which traps air, so the glue does not penetrate down to solid wood. Also, the drying of glue, which makes it shrink in volume, enhances this effect. The best surface for gluing is smooth, as after scraping, with clean grooves running always along the glued parts (parallel to limbs of bow). Only then the glue can bond well and will saturate the surface (the surfaces should be dried on the side to avoid collecting the glue and trapping air inside the grooves).

For best bonding, there must be enough glue in the joints, because the glue tends to sink into the wood, leaving too little for a good bond (remember the glue also looses volume as it dries). It is best to make sure the surfaces are coated enough times with the thin glue to make the dry glue look glossy. Then a coat of thicker glue (20-35%) is put on and the parts pressed together. To further reduce the viscosity of glue on wood, the parts should be heated before applying glue.

As long as the thick, liquid glue completely fills the joint, there is no need to rush with clamping. The glue gels in the joint, holding the parts together securely. Then the clamps are used. If the parts fit well, no clamping is needed. This is one of the reasons why it is best to use a glue that gels at the temperature of you workshop (this may vary).

I hope it helps.

Adam

ADAM: It is a common mistake to "roughen" the wood for gluing, by sanding or rasping. This creates fuzzy surface which traps air, so the glue does not penetrate down to solid wood.

Ooh... that's interesting. Received wisdom has it that surfaces should be scraped/roughened to increase the contact surface area between the components. Some bowers are even gouging zig-zag grooves with a special tool. Is that a mistake? Or can both be correct (i.e. increased contact surface area but no air bubbles)?

S.

For a long time I did these zig-zags, but after having done it, I smooth the fuzzy surface. Now I prefer the grooving running along the limbs of the bow, but you have to do it very carefully and looking for a clean surface. So adhesive powers are provocated too.
The need for "roughing" the surface depends on the kind of wood you use, cause there are more or less pored woods. Maple is the best wood for a glueing, it is even used in modern bowery and woodworking.
The secret for a successful glueing is to check the right temperatures and warmth. If everything fits perfectly no clamps are necessary, hideglue will squeeze away very easily if you use to much pressure for the glueing.
Hideglue is a very good filling-material too, but you?ve to keep in mind that it shrinks while drying.
Another common mistake is that many bowyers think the drying of the glueing is finished after 2-4 weeks. The gluing is dried out after this time, if you check the physical weight of a drying hornbow there will be very soon only a very small or no amount in loss of humidity. But the determing action what happens is the polymerisation and this needs much more time. I guess about 4-12 month, it depends on the thickness of the sinew-backing.

Michael

Any scratching or grooving in the diagonal or across the limbs cuts across the fibres of wood. You can get away with it in a 50lb bow but not in a 100lb...

Adam

Adam Karpowicz wrote:

Any scratching or grooving in the diagonal or across the limbs cuts across the fibres of wood. You can get away with it in a 50lb bow but not in a 100lb...

Ok; but is your overall recommendation to leave out grooving and just go for a smooth surface where air bubbles can't be trapped?

Another implication: wherever glue is applied, the materials need to be as warm as possible before applying glue. If the glue itself causes the heating, then trapped air will expand. If the materials are already hot, then the cooling of the glue and materials will result if contraction of any air pockets.

This has been fairly obvious to me for some time, but it's worth rehearsing here for general readers.

I think that Adam recommends a clean grooving along the limbs of the bow. To warm the glueing-parts is obligatory.
Michael

if I read some of the sources well than the chinese applyied up to 70! coats of glue before glueing the horn. would you agree with this information.

and second if I read Hein well he states that glue is applyied in several coats, dried and than the wood pieces heated and pressed together. I have not tried this method. do you think this would work, or does glue need to be liquid?

stefan
ps I am still working on those xrays but I have a hard time scanning them right or making good fotos.

Yes, I always make grooves. For wood to wood contact shallow grooves are ok. I suspect in some cases a smooth, non-grooved surface may be sufficient for wood - consider the methods by instrument makers to glue two halfs of violin tops. The thickness of wood is only around 5mm along the joint, but the glue holds perfectly for centuries.

The glue, if made very thin like water (1-2%), is sufficiently fluid so the heating of parts is not required. Of course many coats are needed to make the parts glossy for the final glue-up with the concentrated glue.

Adam

hi Adam,

I'm not sure I understand what you wrote.

so you mean that the wood core needs to be soaked with more diluted glue, 1% glue and 99% water?

and if the glue layer is thick enough you can heat the parts up and stick the together without having to apply one more fluid layer of glue?

or after several coats of fluid glue you apply a thicker one like sirup?

stefan

the question is still open:

do I need three different glue consistencies for joining the core, for soaking the core and for applying the sinew???

and if yes which is the right dilution?

so far I used the same solution for all purposes. was it a mistake???

stefan

This answer will probably just frustrate you. :?

In 18-19th Century China, three different qualities of glue were used on bows:

#1: gluing wood siyahs to the core and gluing the horn belly to the core.
#2: gluing the sinew to the back
#3: gluing the birch-bark onto the limbs. (Birch bark resists penetration of moisture.)

A small quantity of lead oxide was sometimes added to the glue. The purpose is not clear to me. In addition, surfaces to be glued were cleaned with an strong alkaline solution (lye) and then wetted with human saliva. (Purpose unclear. It is an ancient tradition of Chinese crafts that some bodily fluid, hair or nail-clippings of the craftsman be added to his materials. It may have been for superstitious, magical purposes.)

I do not have any details of how these different qualities of glue were achieved.

It could have been lead acetate (sugar of lead) which would dissolve in the glue completely unlike the oxide (creating a suspension). Perhaps both were used. I understand the lead in glue would discourage rodents or insects.

The three categories of glue are correct, although the wood to wood joinery does not require such elaborate preparations as horn to wood.

Stefan: There are several composite bowmakers in Germany. You may want to contact them directly.

Adam

alkaline solution and saliva were used to degrease the wood surface. lime is still used to degrease wood in woodworking and the human saliva contains enzymes that break down sugar. inuits used to even tan hides for making cayaks by chewing the leather thoroughly. must have been fun in dark winter nights. but this was a job for the women. you see how far people would go that dont have chewing gum ;-)

stefan

What is "lime" in english? I find that lime stone is calcium carbonate rock. Is lime that white thing used for painting walls in white? Is it like yogurt but very white?

Rapsod wrote:

What is "lime" in english? I find that lime stone is calcium carbonate rock. Is lime that white thing used for painting walls in white? Is it like yogurt but very white?

Yes, this is it. It starts boiling when mixed with water.....

[quote="Stephen Selby"]

#1: gluing wood siyahs to the core and gluing the horn belly to the core.
#2: gluing the sinew to the back
#3: gluing the birch-bark onto the limbs. (Birch bark resists penetration of moisture.)

I do not have any details of how these different qualities of glue were achieved.[/quote]

does anyone have more information on this?
I guess it's just a difference in the water/glue ratio. but what is your experience or how do you do it? do you really use different glue solutions/dilutions for these tree jobs?

stefan

if the gule not good work, use the sinew string or silk bind (ensnarl) them together,it is a incipient method,

ps:what reason our modern people very obsessive to these old time technology?it is year of 2006.......

Please find attached an interesting picture of a broken Turkish bow I took some time ago. The groovings are about 1,5 mm deep.

They are all along the limbs, no zig-zags, no rasping or sanding!

R

And here the perfect tool I use....

I get it from:

http://www.toolpost.co.uk/system/index.html


or Germans/Austrians/Swiss from:

www.feinewerkzeuge.de


Reto

I always thought that the groovings where somewhat deeper than 1,5 mm. I also thought they where rather large....

(Ok: These Questions are not from an ultimate craftsman....so excuse me).

That Veritas scraper blade: Do you use it by hand or does one need the fitting plane for it? I have seen, there are a number of toothed blades offered from other manufacturers, some have V shaped teeth and some have square shaped teeth - some are as cheap as 10$, others cost more than 60$.

Question: is such a shallow grooving really sufficiant? What tool was used by
ancient turkish bowyers? Any Details on that tool?
Maybe we should open a new thread only about grooving...???

Alam, I know Reto and this tool, you use it by your hands. With this tool it is really easy to do sufficient grooves. But it would be the best to take a piece of wood and horn for to make some experience with that grooving-tool. 10 years ago I did not know that you can buy such a scraper, so I did one by myself according to the "Eisernen Kamm" you can see in Hein?s book.
I?m not sure if the grooving is necessary for hornbows weaker than 50lbs, but I do it anyway. Adhesion-power could also do a good job.
The largeness of the grooves is not so important as the proper relation between the number and the largeness. You have to take care that the horn and the core will not be weakened by the grooving.
Have a look at the old books and the accordant pages in the ATARN and you will do it right. They know what is to do.

Michael

and here how I do it ....

pic 2/2

Thank you Reto, Redhawk.

I understood a lot from the photos. One question: I see two toothed scrapers.
It's a good idea to fix something on them that will slide along the egde of the
bench. Do I asume right, in that you first use the veritas toothed scraper and later the scraper with the larger teeth(the one with the two holes) to enlarge the grooves? Did you make the latter scraper yourself?

Redhawk
You mentioned Hein's book. What is his full name & title of the book (Klopstek????)

Greetings - and thanks again

(though I started a new thread about grooving questions, I linked it to this one)

Both scrapers are perfect! The homemade-one and the Veritas one are 1,5mm deep (). It could not make a better picture of the veritas blade. I use both scrapers.


About the literature:

In German:
Hein, J.: Bogenhandwerk und Bogensport bei den Osmanen nach dem 'Auszug der Abhandlungen der Bogensch?tzen' (telhis resail er-rumat) des Mustafa Kani. In: Der Islam, 14, 1925, pp.289-360*

http://www.orientarch.uni-halle.de/sfb5 ... vey/05.htm

You can get this book from: http://www.orientarch.uni-halle.de


In English:
Turkish Archery and the Composite Bow by Paul E. Klopstg

You can get this book from: http://www.museum.man.ac.uk/

Reto



http://www.museum.man.ac.uk/

Thank you.

Is there any reason a more modern glue cannot be used to glue the horn?

Marc,
there are 2 "premium-reasons" for to use hide- or fish-glue in hornbowery: hide- and fishglue are much more elastic and durable than every modern-glue.
At any rate you will have a better and more durable bow.

I don?t know if it is possible to glue horn with a modern glue?

Michael

Actually Michael you are mistaken on at least 1 count. Hide glue is less elastic than most modern glues. Hide glue is more durable though. I have used PVA glues to glue down horn overlays many times. PVA glues actually stick better to horn than hide glue does.

Marc, o.k. but the point is: could PVA do a good job when you glue horn in the working section of a bow?

Michael

Michael
As I said. PVA glues stick to horn very well as well as as they stick to wood. I, along with many others, have used TB2 & 3 to glue down many wood backings including Bamboo to wood cores and they do the job quite well. If it works that well with wood then there's no reason to think it wouldn't work as well with horn.

Just wondering if anyone has used a modern glue for a horn bow or even if they have thought of doing so. As a side note, I wouldn't use anything but hide glue for sinew.

Marc,

Hornbows currently made in Mongolia are made with modern chemical glues, because no natural glues are available. These glues are considered unreliable, so Mongolian people wrap their bows in nylon fishing line to prevent catastrophic failure. Craftsmen in north Tibet have also been using modern glues and find them unreliable.

S

What can one learn about traditional Asian archery by using synthetic glue? If you want the thrill of shooting an authentic type ancient bow, then use origional materials. If you make your own bow and arrows from scratch, you can hold your head proud in any group of archers.

No matter how accurate and fast a compound may be, you cannot squeeze an ounce of spirit out of it. Go to ebay and see how many used compounds and synthetics are for sale. Then just try to find a real horn bow. They are thousands to one. -j-

I?m sure that the glueing of horn to the core of a hornbow is very unreliable, it even will not work for a longer time?
What never will happen by glueing horn with a modern glue is the necessary polymerisation of the proteins of the horn, sinew-fibres and the glue itself.
This polymerisation is the main reason for the outstanding performance of a hornbow. It needs time and this is the main reason for the long drying-time a hornbow needs. What really happens is polymerisation and not drying. Humidity has left the bow after a few weeks up to a degree depen-ding on the environments.

Jack, I agree with you 100%.

I would like to add that modern glues are very toxic, very extensive to produce and are based on petrol, which is the main reason for the suffering all over our planet.

As Robert Redford said: mankind needs at once a withdrawal treatment of petrol.

Michael

Stephen
Maybe it depends on the type of glue? As I said I have used PVA glues for horn overlays and it works great. I have read that if you want a glue joint to last several hundreds of years then use hide glue. That may be the case but modern glues have not been around long enough to determine that.

Jack
Personally I am not interested in that type of pride. My main interest is function along with aesthetics but primarily function. Keeping the craft alive is a noble cause though and I admire those that do that. Seeing as how I have no interest in wheel bows I will pass on checking out ebay. I have made several hundred bows so I'm not new to this art. Horn bows though I am new at.

Michael
The performance of the horn bow has nothing to do with polymerisation. It is a function of design and proper use of materials. The high compression strength and elasticity of the horn along with the elasticity of the sinew allows for a high storage of energy.

Performance is what I am looking for here

Marc,

could you eplain me why it is necessary to dry a hornbow for 4 - 12 months? As I?ve mentioned yesterday, humidity will have left the bow after a few weeks (depending on the environment).

It is the big mistake of Jim Hamm and the Bowyers Bible to have posted that a sinew-backing is ready after 2 - 4 weeks drying- time!

Polymerisation is the key, it is nothing magic.
Erhard Godehardt with whom I did some reproductions of scythian and actually do greek hornbows, will do some scientifically research about it.

I don?t have any sense of understanding for using modern glues for traditional bows, cause everybody knows that they will not have a long life.
I do all my bows with hide- or fish glue, this also a question of aesthetics.
I?m sure that even a bamboo-backed bow will have better performance by using hide-glue.
Have you ever seen a plastic bag lasting more than 5 years?

Today we have the choice to use the old or the modern glues, it depends on your state of mind what you do, I prefer to go back to the future.

Michael

Micheal
It is not necessary to dry a bow that long but it is best to. I have sinew backed bows that I have tillered out after a few weeks and other that I've tillered out after a few months. The is very little difference between the 2. A sinew backed bow that has dried and cured for several months will be more stable, that is to say the tiller is not as likely to go off. Exactly what makes you think that polymerisation occurs? Frankly that does not make much sense to me. In any case I'm not talking about the sinew here as I have already said I wouldn't use anything but hide glue for that.

Redhawk, very interesting what you said about the process of polymerisation.