Sinew or rawhide? Lots a pix added!

[b.glass]

I was working on some kids bows yesterday afternoon and decided to take a break and work on my eastern red cedar stave.

Well I couldn't seem to put it down and I'm near the backing issue. I had been thinking rawhide all along but since looking through one of the Bowyers Bibles, I have been contimplating sinew.

I also have some knot issues I'm not sure how to handle. I have rawhide backed a board bow a few years ago and have never sinew backed.

[Silent Bear]

How long is the bow you are working on ? if shorter I would use sinew

[walkabout]

i agree with silent bear, if its short then sinew will help a bit. as far as knots it depends on the type, usually just leave extra wood around them and scrape outward around them in all directions to form a moundlike section to help keep them strong. if theyre knots that have holes then fill them with either superglue or i use homemade wood putty made with tb3 and sawdust. just be sure to pack the putty in tight and make sure you put a little glue inside the knot first to ensure good gluing, since tb3 shrinks as it dries. pics would help to see what kinda knots youre dealing with.

[ChristopherO]

Mona,
I've never used Cedar so those more versed in that wood can steer you better but if it is a softer wood, belly wise, sinew may overpower it.  Anyone with Cedar experience care to chime in?

[b.glass]

Well, I've always thought the same thing Chris, until lately. TBBIV page 39, says that it is very similar to yew in that it is well matched to sinew, being VERY good in compression. I bought a nice stave at the Hoosier Bow Jam a couple of years ago.

I took some pictures a bit ago and will post them as soon as I can.

[walkabout]

im not sure if the sinew would overpower it but if TBB says its a good match then id probably try it. ive never built with cedar full scale for bows but built a prod for a mini bollista with some cedar shims.lol

[b.glass]

Here are the pictures I promised. First, working the stave on the bow horse an couple of weeks ago.
 

[b.glass]

Then where I left it yesterday. The upper limb.

 

The lower limb.

 

[b.glass]

A close up of the mid-limb knot on the back side...

 

...and on the belly side.

 

[b.glass]

The knot hole on the upper limb near the tip...

 

...and the handle.

 

There is also a knot on the handle that will be the upper part of the handle on the arrow side.

[b.glass]

Have any of you all read "The Bent Stick" by Paul Comstock?

His first rule is "Don't panic".

Well I just measured the bow so I could give you the exact deminsions...

The lower limb is 4 1/2 inches shorter than the upper limb. How did that happen???

[b.glass]

The bow is 63 7/8" tip to tip. The upper limb is 30" from tip to fade. The lower limb is 25 1/2" from fade to tip.

If I take 2.5" off the upper limb it will still be a 61" bow. I want to get 50# at 26" draw.

[walkabout]

that ones got tons of character,lol. 60 inch and shorter bows take better advantage of sinew from what ive been told,as far as the knots go try soaking the ones that arent holes with superglue. the ones with holes im not sure, ive seen some people leave them and others filled them. ,maybe someone else with more experience with those type of knots can help. all i know is its best to leave a decent amount of wood around them to do the work for the missing wood and the wierd grain. the one in the top limb might not be much of an issue since its close to nock point, less stress out there than say midlimb.

[walkabout]

if you end up filling the knot with the hole using wood putty, tape a piece of plastic then cardboard over the opposite side that you plan on filling from. mix your putty and push it into the knot,going until you think its compressed as much as possible, then continue to fill till its level with the rest of the limb. i wrap my patches with sandwich baggies then clamp wood blocks over them to get the airgaps out of the putty, figure its kinda like making plywood of sorts in there and gaps are bad.you might find an easier way for you to do it with what you got, this way just works best for me. end result is really strong if you pack it tight, even reacts to tools like wood does with the exception of fine sandpaper of course which gunks up fast.

[b.glass]

When I take 2.5" off the top limb that knot hole will be eliminated. So I leave the extra wood around the other knots as if it will be a selfbow? I've also learned that I need to take off all the sapwood.

[walkabout]

yep from what i know you treat them just as any other selfbow, im not sure how the sinew would affect them but id guess it would still stress the knots the same. you should find out once you get it to tillering phase if they end up stiff. i dont know alot about the sinew but from what i do know it seems like the smart thing to do. frank on here seems to use sinew alot from his posts on here, you could pm him for advice too.

[Pat B]

Bona, I think ERC and sinew should make an excellent bow. ERC is a Juniper(J. virginiana) and the Western Plains Native Americans used sinew backed Juniper for many of their bows. I have a 49" flatbow cut out and somewhat shaped that is 50/50 sap/heart wood that I plan to back with sinew.
  I have heard that the sinew will separate the sapwood from the heartwood as it dries but don't know this for a fact.
  To get the most out of sinew, short is the trick. For protection of the bows back a single layer of sinew will work like rawhide but with possibly a bit more oomph!

[b.glass]

Thanks everyone for your input. I will still fill a knot hole in the  handle section as described. It isn't all the way through but it is also a little torn out from when the stave was split.

I will also take off the rest of the sapwood just to be safe. Along with sapwood and heartwood seperating, in "The Bent Stick", Paul tells of sinew backing a yew stave with sapwood left on that was deflexed by 5" the next day.  

Doesn't Gary Davis tie the handle down in reflex when he sinew backs his bows? The sinew should pull the bow into reflex anyway, so is this for insurance?

[Mike Yancey]

If you are going to sinew back it I would leave the sap wood on and just get the back flat. Put a block on each end and pull into reflex at the handle and sinew. The sinew and cedar are a good combo, I am tillering one just like it right now and have shot many of Ed Scotts bows made out of the same stuff.
Mike

[b.glass]

Hey Mike, thanks for the advice. I've already taken off alot of the sapwood. I haven't been able to get it all off, so I will stop trying. It is pretty flat now, so I'm ready for the sinew.

Do you think 50# @ 26" will be ok? It should end up 59" nock to nock.