Sinew problem

[osage outlaw]

I am working on an osage selfbow that I sinew backed for the first time.  I used knox gelatin glue and put down two layers of sinew.  I sized the back with glue before putting the sinew down.  I got the bow tillered and decided to shoot it a few times.  After I shot maybe a dozen arrows, I noticed a small area on the side of one limb about 4" long where the sinew looked like it had pulled loose.  I could see a little gap between the wood and the sinew.  This area is about 6" down from the botom fade.  I put some super glue in the small crack because I didn't think hide glue would be thin enough.  Should I wrap the limb in that area with sinew and glue?  Will this repair work, or is my sinew job ruined? 

[Timo]

Try it without the wrap and see if it will work,before you do any thing else.Sinew is very versatile stuff, hard to screw up. If it doesn't hold then wrap it. If that don't work, just lay it in the stock tank and soak it off, redo.

[Eric Garza]

I've had mixed luck sinew backing osage.  It's very oily wood, so you need to de-grease it before hide glue sticks well.  My guess is that this is your problem, you didn't degrease it well enough before you sinew backed it.  If this is the problem, you can soak the bow in water to get the sinew off, do a really good job degreasing, then glue the sinew back on and it should hold much better.

[spinney]

Hi outlaw,

I had the same thing happen to my sinew backed osage recurve.
I fixed it with super glue too.
The good news is it has held up very well no problems at all.

Andrew

[osage outlaw]

I degreased it with acetone several times.  Maybe I missed that area.  Will wrapping it around the limb with sinew help?  If it holds down splinters, I think it might help with the sinew.

[gstoneberg]

I've only used hide glue on my osage sinew backed bows and so far I've never had sinew not stick to the bow.  But, to answer your question, yes - you can certainly wrap your bow with sinew or any other cordage and hold the loose spot in place.  I would not have hesitated to run some warm hide glue under a lifted spot and then rewrap and dry.  Putting super glue on the sinew makes that spot not reusable if you submerge the bow to get the sinew back off. 

Did you rough up the bow's back to give the sinew and glue something to hang on to?  Was it wrapped with an ace bandage after application?  How long did you let the glue dry before flexing the bow.  You've already answered the degrease question.  The major problems you can get into are:  poor back preparation (degreasing and leaving it too smooth), too hot a glue, failure to wrap the bow to hold the sinew against the back firmly, and insufficient drying time.

Good luck, I hope your repair works out great.

George

[osage outlaw]

I used a hacksaw blade to rough up the back before I degreased it.  Maybe my glue was a little hot.  I was using a heat plate off of an old coffee maker.  I did not wrap the bow after I put the sinew on.  I let it dry for a few weeks before I started bending it.

[gstoneberg]

The glue being too hot is more likely to affect sinew strength than bonding now that I think about it.  Sounds to me like the spot in question wasn't against the bow back tight enough to get good adhesion.  Here's how my last bow looked after applying sinew and wrapping:



I took pictures of the whole sinew process.  If it would help I can post them all.

George

[osage outlaw]

That would be great.  I would love to see a sinew build-a-long.  Thanks.

[gstoneberg]

OK, tonight when I get home from work I'll create a sinew build-a-long in the build-a-long section.  If I think about it I'll post a reply here so you'll know.  You might want to reply to this to help me remember.  Old age stinks.  George

[osage outlaw]

Thanks.  I look forward to seeing it.

[gstoneberg]

OK, I finally got it posted.  I hope it helps.

George