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Broken Bow

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simk:
proof?

I for example have this horn-sinew-wood composite. I opened it carelessly and braced step-through-method after the sinew was dry. it hasnt been tillered.....lesson learnt.

I braced the bow again and put resin on one side. After a little while it came out the other side of the hairline crack. I unstringed the bow, and after curing I finished the bow and it serves me well now as a personal bow and test bow since summer. Yes I also added a little extra sinew to the area. Nevertheless its amazing that this works even in the most stressed part of the bow right where the powerlam ends.

I have fixed a lots of hairline cracks and checks that way and they never came back. Actually you cannot check weather there's glue in every crack finally - its a similar thing as going to church - just have to believe  :OK

Eric Krewson:
You can also use compressed air to blow the glue through the break.

JW_Halverson:

--- Quote from: simk on January 16, 2026, 07:47:00 am ---there's a simple trick boys!

dont pull it apart and don't use epoxy like west sytems or ea 40. those are artificially thickend with thixotropic agents.

use a casting resin suitable for wood. these normally are used for making laminations of fiber cloth and they are designed to creep.

pour it in that crack and it will quickly displaces ALL of the air and automatically creep into every crack. no heating required, room temp is just fine. use one that has a open time of at least 60 min and clamp after 30min. If the crack goes all through seal it well on one side with super adhesive tape - ducktape does not work, the epoxy creeps underneath!

cheers

--- End quote ---

Wow! That's a brand new word to me. Thixoptropic. Had to look it up and per Wikipedia:
Thixotropy is a time-dependent shear thinning property. Certain gels or fluids that are thick or viscous under static conditions will flow (become thinner, less viscous) over time when shaken, agitated, shear-stressed, or otherwise stressed (time-dependent viscosity). They then take a fixed time to return to a more viscous state.[1] Some non-Newtonian pseudoplastic fluids show a time-dependent change in viscosity; the longer the fluid undergoes shear stress, the lower its viscosity. A thixotropic fluid is a fluid which takes a finite time to attain equilibrium viscosity when introduced to a steep change in shear rate. Some thixotropic fluids return to a gel state almost instantly, such as ketchup, and are called pseudoplastic fluids. Others such as yogurt take much longer and can become nearly solid. Many gels and colloids are thixotropic materials, exhibiting a stable form at rest but becoming fluid when agitated. Thixotropy arises because particles or structured solutes require time to organize.

Thank you for the new word and concept, Simk.

Selfbowman:
Send it to me and I’ll fix it if fixable

RyanY:
Hard to tell why it broke from the pic. It could definitely be glued together but whether it will hold up may depend on why it broke in the first place. I wonder if there was a shake that opened up. I’d definitely try to glue it and see what happens.  (-P

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