Sinew-Backed ERC Recurve - Repaired p.2

[LittleBen]

I hope you all enjoy, this is one I've been working on for maybe 6mo on and off. Took this from live tree to shooting in about 1 year I'd guess. It was a pretty knotty stave so I was a little skeptical, but it seems to be doing OK.
Specs:
58"NTN ~2" wide at the fades, ~3/8" tips
Hickory underlays on the recurves, and accent stripe in the handle.
Buffalo horn tip overlays.
Elk back sinew and deer leg sinew, 3 courses total. About 3/32" total thickness.
43# @ 25"

Any advice and comments are welcome. Thanks!

Here is the bow strung, hanging on the rack.
     

Immediately after being unstrung, showing just about 2.5" of reflex.
     

Some more pics of the bow.
     
     
     
     
     

[LittleBen]

It does have one major flaw, It developed a pretty nice compression fracture

 
 

I shot the bow in at Canopyboy's range, and we both inspected it pretty thoroughly, the fret developed during tillering very early, and has not progressed past the knot. We discussed it and decided that as long as the bow doesn't develop a hing there, or develop twist, or the fret cross the knot, it should be fine. Any and all opinions welcome. Thanks.

[PEARL DRUMS]

Well that sucks Ben. I don't think she will last too long with that fret wrapping around like it is. The sinew kept you from a broken nose!

[Black Mockingbird]

Sometimes a fret will happen ON a knot,and its usually OK as long as its contained or doesn't run off the edge...as in the case yours does...hard to say how long that'll last...but its iffy for sure the way it is...I would do a sinew wrap at the very least an inch before and after it to cover that up...the best fix might be a wood patch,and even a possible wrap over the patch...as is I personally don't like seeing it going off the edge and almost up to the tension side of the bow....

[Bowjunkie]

I'd patch it via ye ol Torges patch.

Nice profile.

[Art B]

That's a pretty simple fix Ben. Use the dowel method to fix that fret. Looks like you're going to need to know how to fix at least one more from what I see. Here's how you fix it:

Take a round file and groove out (but no more than half the dia of your file) that fret. Now round out a suitable dowel to fill it in with. Use super glue gel to glue it in with. Rasp/file/sand down...........Art

[LittleBen]

Thanks Art. The other fret shown there is fully contained in the knot, and is very very minor and not progressing.

I will definately consider using a patch to fill the large fret there ....

I guess I'll need to get a piece of cedar to fill it or do you use another type of wood.

My only concern with the dowel is that the wood is not as string in compression across the grain as it is parallel to the grain, so the dowel must necessarily be weaker ... right?

Black Mockingbird ... the fret formed very early in tilling ... like it was super weak there. Hasn't gotten any worse through shooting in, just been watchign ti carefully. The side doesn;t bother me, but liek you said what really bothers me is if it approaches the tension side of the limb. Right now the picture is kinda deceiving, makes it look like it runs nearly to the back, but actually it's got a pretty substantial crown, so it runs to about the neutral plane ... although I guess thats as far as any fret can ever go because by definition, at the neutral plane theres no compressive stress.

Well anyway, sounds like I may need to consider a fix on this one. Hate to do it but if I must ... Any thoughts on whether I should insert a cedar dowel, or a hardwood dowel like IPE or something. My concern is that a dowel of harder wood may cause too much stress in the surrounding belly wood because it won't compress as much as the cedar.

[Bowjunkie]

Yep, I'd use the same wood type, and same grain orientation if possible.

[Art B]

My first fix like that was an Osage bow Ben. Heat crack from setting back while tempering just out side the fades on both limbs. I grooved and doweled using a store bought dowel, maple maybe. That worked so well I later replaced with Osage dowels and thread wrapped for insurance.

So, using the dowel system, across the grain, just outside the fade, isn't a testament to it's viability, then I don't know what is.......Art

[Art B]

Sent you PM Ben........Art

[takefive]

That's a pretty bow, Ben.  Did you steam the tips or use dry heat to recurve them?  Hope your fix works and it keeps shooting for you.

[scars]

Your Bow looks great Little Ben. I like the idea of using hickory as stiffeners on the recurves. Good luck on the repair.

Joe

[LittleBen]

Thought I would give an update on this bow. It's been shot a few times, the one bad chrysal has expanded. I'm considering trying the plug repair now and/or some light additional sinewing around the side of the limb at the chrysal, and a sinew wrap around the limb in order to keep it pressed down.

Also I scaled the bow again, and the weight has jumped to 56#@26" ..... I guess it wasn't fully dry.

[Pat B]

56#@26" is just what I like to shoot. d;^)

[fujimo]

wow- really cool Ben.
the torges patch will just add a little character/
very sexy lines!!

[Bob at Work]

I have wanted to make a bow like this for years...even downed a really straight 16" tree last year and just split it into staves last week...I'm pretty sure I have a couple with nearly no knots.
Question 1- my sapwood is 1/2-1" thick on the staves and I think I'd like more red heartwood, at least for the belly...did you decrown yours?  Anyone know which is stronger, sapwood or heartwood?
Question 2- Are your dimensions the best for this type of bow even if I'm tillering to 28".  2" wide and 58" long...?  
Question 3- heat or steam for the bends on dry ERC?

-Keep us posted on your repairs... great looking bow...!

Thanks!
Bob

[PEARL DRUMS]

Hey Ben. How about you thin that belly down about half its thickness and add an ipe or osage slat that starts at the grip and fades in to the last 6" of limb tip? That would bomb proof it and give all the weight in the world to work with. Just a thought.

[LittleBen]

Chris, I've been thinking of doing exactly that. Definitely the safest plan.

Bob, I do not think this is necessarily he best length for any draw length. This bow was designed for me with 25" draw. You might wanna consider going longer for a longer draw or have less static tip. I did decrown the stave. If you're sinew backing it doesn't matter if you violate rings.

ERC is very lightweight. So I recommend going wide for whatever length you choose compared to what you're used to. Probably twice as wide almost as Osage would need. Also I recommend using Steve gardner's mass formula to keep on track in terms of having enough length and width for the target draw weight  and length.

[Bob at Work]

Thanks Little Ben... looking forward to seeing how it comes out.
Bob

[Art B]

You could have prevented that fret from expanding had you responded to my PM Ben. I was going to show you step by step instructions for a quick and reliable fix. Anyways, I hope find a repair that fixes your problem...........ART