repair help on short Hupo sinew backed bow

[loefflerchuck]

I agree with George. It's not rocket science. The more I work with sinew the more I realise this. I also reuse sinew from a broken bow. Soak it for a long time then use a comb to brush it out. First I would try and fix it though. I have never used crazy glue on sinew. It may work but sounds scary. You said you wash each layer of sinew before gluing?  Just lightly score with a hacksaw for better bonding.

[wally]

Here is pic.
First answer question Loefflerchuck. Some one asked me if I washed sinew before each layer but I said I didn't, in fact I'm not sure what they meant.
I'm going for a repair job.
Marc says cyanoacrylate glue is best to use, other say stick to hide glue?
I have nothing against using modern glues although instinct say use natural.
Any opinions

[MWirwicki]

I'm sorry, but that is simply not true, provided the sinew is not covered with a finish.  Hide glue is water soluble and when a bow with hide glue is soaked in water the glue dissolves and the sinew releases from the wood.  In time it can be easily removed from the bow, dried and reused.  I have done it, and it works fine. 

George
[/quote]

Thanks for the tip, George.  We learn something new all of the time with this hobby of ours.  I'll have to try that!

[gstoneberg]

No problem Matt, and I really hope you don't have to remove sinew that way.  It means a bow didn't work or broke and it's painful after all that work sinewing.  On the other hand, bows protected by sinew are very durable if protected from moisture.  I normally back them with snakeskin them to make them more weatherproof.

Wally, seeing your picture makes me more concerned.  I thought the sinew just lifted, but it appears that one end has come completely loose, so it no longer has continuity.  I'm anxious to hear Marc and the others with more experience comment.   I'm in a bit of a quandary as to your best approach now.   I wonder if you need to not only glue that piece down, but also add a little sinew over the top to tie it in?

George

[loefflerchuck]

Not a good picture but it does look to me like it is not connected on the rignt side. How could that happen to a full 3 layers unless the sinew was not staggered? If it was just lifted I would say easy fix. Some Hupa bows had a solid rawhide wrap for a handle that would further strengthen this fix

[wally]

Yes it doesn't look good. The sinew was staggered and at the end that is free you can see the layering with some long and short pieces.
It first lifted by remaining in place, while the bow and first 2 layers seperated and bent more, then finally virtually broke free. It was still loosely tagged at that point but I easily freed it so it was completely loose.
I'm assuming that that layer was the weakest bonded, either through my bad mix of hide glue and water,or not so well placed on?
I'm still thinking that if I glue the flap down and cover it with more sinew, then transverse sinew it on top of that, about the handle area, and finally tiller the limbs down slightly so they take more bend?
At 19" it was pulling 48lb so I think it can come down more?

[Marc St Louis]

First of all I didn't say the crazy glue was best to use, I said you can use it.  It can be useful where the sinew has lifted but not enough that you can get in there and clean it properly for the repair.  In this case it has lifted clear and you have access to the lower layer for cleaning.  I would tug a bit on the sinew that has lifted to see if the rest of it will pull off.  If it does so easily then it may be best to remove that layer completely and redo it.  You would hate to repair that part just to have another section start to lift as you start tillering again.  Obviously if you were in the process of tillering then you must not have a finish on the bow yet so re-using the sinew should not be a problem

[loefflerchuck]

Marc has a good point. See if that whole layer wants to pull free. If it does. Redo the top 3 layers. You can doo em all at once to save time. If not. Soak the loose flap, reglue. layer more on top and wrap.

[crooketarrow]

   Thats a very big lift up. You can fix and rap, most short bows were rap after tillering in places the whole way to prevent just this. The only problem this fixing a place of lifted so big the wood may not be reflex the way the rest of the bow will be.  7 Day between layers is fine as long as you don't flex the limbs between layers. I wait say 10 days  reflex a few times between layers. Don't reflex to far are put unwanted stress on your limbs remember it's not tillered.
    When finished I'd let it dry say 2 weeks before you finish the tiller. Then after since it's so short I rap with sinew at interments say every 2 inch's. Just to be safe. But you don't have to. Theres no hurry between layers or you might have the problems you have now. Plus I say 3 layers would be plenty. But take what I say with a grain of salt I've never made a bow that short. But I have seen 2 real plains bows and they were sinewed and then rapped and these rappings looked really heavy.
   Like GSTONEBERG said it's a lot of work but with water and a hair dryer or the sun you can save all your sinew. It sucks but I've done it. Personally I'd re sinew like it said thats no small separation.