Sinew backed prod - hide glue cracking under stress? UPDATE: Bow is braced (pic)

[tkdHayk]

I've never found  glue/water ratio made any difference to cracking or not. It all dries to about  90% or so glue.  What a higher initial ratio will give you is potentially more total glue left over which is where people run into cracking problems as many have noted.

 Thick glue well squeezed out to the optimum glue/sinew ratio doesn't make cracking noises.

hey Pat, do you see any disadvantage to using too much glue, as I have on this bow? Can using too much hide glue cause a sinew backing to fail?

[PatM]

If it's cracking the structural integrity is being compromised. Any time you make a composite material the idea is for both materials to do their part.
 So  whatever is causing the cracking is the start of failure.

[tkdHayk]

If it's cracking the structural integrity is being compromised. Any time you make a composite material the idea is for both materials to do their part.
 So  whatever is causing the cracking is the start of failure.

What do you think I should I do at this point? Add some backing to the glue? wet the glue and smudge off the excess glue and erase cracks? continue as if everything is cool?

[DC]

Pat, is it to late to wrap it and heat it to get rid of the excess?

[PatM]

Yes. It needs to have moisture to flow. I would just soak it off and re-do it.

[tkdHayk]

Pat, is it to late to wrap it and heat it to get rid of the excess?

Wrap it with what?

[tkdHayk]

Yes. It needs to have moisture to flow. I would just soak it off and re-do it.

what need to have moisture to flow?

[DC]

I was asking if this method would work after it was cured.
http://www.primitivearcher.com/smf/index.php/topic,43246.0.html

[tkdHayk]

I was asking if this method would work after it was cured.
http://www.primitivearcher.com/smf/index.php/topic,43246.0.html

that clarifies thanks. I could re heat and add water, then use that technique, but that would dilute my glue too much. I think the best solution at this point is to  add an extra layer of sinew, using less glue than before. the added heat and moisture form the sinew application process will cause the hide glue cracks to liquify. Plus, it will give me more confidence in drawing this bow. I dont think cracks in the glue will cause sinew to fail because sinew resists much more tension than glue, without breaking.

[BowEd]

tkdHayk...The picture does not show the cracks to be that deep.I think you will be ok.Especially doing the extra what you stated too.I've seen little cross cracks on a sinewed bow of mine before too that is still shooting fine.

[tkdHayk]

tkdHayk...The picture does not show the cracks to be that deep.I think you will be ok.Especially doing the extra what you stated too.I've seen little cross cracks on a sinewed bow of mine before too that is still shooting fine.

I hope so! Just applied another layer of Sinew yesterday with thinner glue. After about 1-2  weeks  I should have the bow braced!

[tkdHayk]

Bow has been strung!

let me know what you think of the tiller. I'm now aiming for 15 inch draw at 70-90#

also wondering if I should cover the cracks in the glue with superglue? good idea? or will the superglue damage/burn the sinew/hide glue?

http://imgur.com/nNaOqmr

[PatM]

Less than a week of drying time?

[tkdHayk]

Less than a week of drying time?

Yup, the previous 3 layers had about 1-2 weeks of drying time, this 4th layer had minimal application of glue, so minimal moisture re introduced to the underlying layers of sinew.

Super glue good or bad idea?

[PatM]

What sort of cracks do you have now?