sinew cracked
Hi ,
I'm sinewing a new bow.
Yesterday I put on the 1 layer.
Today the sinew look's like it is cracked in the lenght direction over the limb.
Like it is spliced in 2 seperat pieces. Afther reheating that section and pushing it with my finger the crack was gone.
Does anybody know what happend???? Like was there air under the sinew or something like that??
Thanks,
Yuna :roll:
I'm sinewing a new bow.
Yesterday I put on the 1 layer.
Today the sinew look's like it is cracked in the lenght direction over the limb.
Like it is spliced in 2 seperat pieces. Afther reheating that section and pushing it with my finger the crack was gone.
Does anybody know what happend???? Like was there air under the sinew or something like that??
Thanks,
Yuna :roll:
It may be that the glue concentration was too low or one strip on the bow was already gelled while the second one was put on. Sometimes the "break" along that line. I would watch the part to be there in case it starts again. In case of a to low glue concentration the cracks should also start to appear on other parts of the bow while driying. You can try to put on glue in a higher conc. but I think it may still be somewhat problematic cause then the adhesion to the wood may also not be sufficuient.
best regards Kevin
best regards Kevin
Thanks Kevin,
I'll try a nother conc. glue.
atb,
Erwin(yuna)
I'll try a nother conc. glue.
atb,
Erwin(yuna)
This also drives me crazy, cracking sinew. It usually happens where the bundles of sinew make a seam. It is because the sinew shrinks drastically as it dries and the fibers are not so well locked together at the place where the bundles overlap. I comb individual bundles of leg sinew shreds, flatten and conform into a piece of tape, scrape up with a knife and lay down on the back; always on a well primed, wet surface and smooth down. When one limb is finished I cover it with a narrow strips of thinnest plastic bag,
One must gauge carefully how long the plastic stays down for if left too long will cause the sinew to mold. I always leave overnight and then remove and put back after some time but very loosely the next time then on and off till finally the surface is dry. The drying sinew can easily be pushed about like clay under the plastic skin. This can produce a faultless surface if much attention is paid.
I think that I am the only one who uses this technique.
One must gauge carefully how long the plastic stays down for if left too long will cause the sinew to mold. I always leave overnight and then remove and put back after some time but very loosely the next time then on and off till finally the surface is dry. The drying sinew can easily be pushed about like clay under the plastic skin. This can produce a faultless surface if much attention is paid.
I think that I am the only one who uses this technique.
:D thank you for this technical hint Jack.
the glue can gel very strong, the sinew has no crack, these glue like milk or butter , if the glue gel very slowly or too poor ability, the sinew crack, the sinew crack for me is not a big trouble, but when sinew glued, i can use my finger rip sinew down form bow, and who can tell me why some bladder glue can not dissolve in water for more than two weeks and no dissolve by steam? :shock: and when i pound the bladders for long time, it geling, i am not hot the bladders
Jiao,
to make glue, you do not heat the bladders ?
do you use cold water ?
to make glue, you do not heat the bladders ?
do you use cold water ?
yes, i am not heat the bladders, it geling strong on the tool and temperature is 25c indoor, very difficulty crush these bladders well, if heat them, when temperature arrive, the bladder become glue immediately
yes, i use cold water
yes, i use cold water