I Need a CSI Unit please. Bow Down

[joebuck]

Ask the brain trust here . Stablized Persimon riser broke into on my 20" tiller stick .  That always fun!!!!  So what do y'all think was the cause. Wood or glue
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[joebuck]

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[joebuck]

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[kennym]

I'm leaning toward wood, but it's hard to tell . When one thing goes, it takes other stuff with it.

[Bvas]

Joe,
I'm not a take down guy nor do I consider myself part of the brain trust.

Just some observation to add food for thought. Hopefully others will comment. But it appears the threaded insert only goes thru the one piece of persimmon. So gains no strength from the laminated layers. Also, have you used this design before, or get it from someone that has?  Seems like the riser extends pretty far past the limb bolts, which would cause more lever action and pulling pressure on the bolts. Maybe it's just the pics, or maybe I'm not thinking correctly.

Again, just throwing thought out. My two cents is only worth about half that. Lol

[Crittergetter]

Like Kenny said, it looks like the wood failed.

And like Bvas said, it most likely failed because it gained no structural strength from the lamination.

Also, something I always do is laminate a piece of glass or g10 along the back of the riser to add more strength. But I also add a g10 I beam during the layup for even more strength and piece of mind.
Takes a little ingenuity but you can do a hidden I beam if you don't want to see it in the finished product

[Roy from Pa]

Doesn't look like a very strong piece of wood.

[Crooked Stic]

Look at the grain direction on your wood goes across the riser. Plus your insert stops above the laminated part. An I-beam would be ideal here.

[Pat B]

With figured, spalted wood I think grain orientation and a separate "I beam" through it is necessary. You can see how that break followed the grain across the riser plus most of the strain in a bow is right at the end of the working limb and the fades, right where this one broke.

[joebuck]

Hey Guys, thanks for all the input!...Bow broke while i had it braced in tiller stick while looking at the ears and tips.    

This was my first riser in 25 years to glue up with Smooth On( always used urac 185 ) and of coarse i cussed it for a couple hours but it wasnt the culprit

Like some of you noted....IMO wood was bad!  ..this was some splated persimmon that had some burl in it. I cut this wood from a trunk/root system and stabilized it myself in cactus Juice to stiffen up. Wood looked and appeared great because it sucked up some juice and doubled in weight . however the grain direction is unaceptable in that area or not enough Juice! ......

I beam???  loving that idea.....hmmmmmmmmmmm  .... any pictures?

I'll go ahead and tiller out my limbs on identical twin riser .......oh by the way Kenny.....they turned out beautiful under your glass...thanks

[Bowjunkie]

Well, burl and homebrew stabilizing juice aside... In that first picture, the wood in the riser looks like an end cut, and it looks like it split like it would if you drove a wedge into a log to split out a stave... it followed the grain. Not good grain orientation for a riser, apparently.

[Pat B]

The grain should run along the riser and not across it.
I've never made a riser for a take down bow or added an I beam so I don't have pics to post. 

[joebuck]

My Cactus Juice didn't hardened the root crotch! .......bummer....this American Ebony is absolutely gorgeous when it splats. I have a question out to the Cactus Juice manufacture if a 2" by 4" is too thick to stabilize..

not all lost....i have a scratch box in mind that i'll fabricate from this riser!

[Pat B]

Be sure the grain runs lengthwise and not across the riser.

[Roy from Pa]

It wasn't the cactus juice.

That was a poor choice of wood for the riser.

And the grain orientation was wrong.

[joebuck]

Interesting, so Roy what has been your experience with Cactus Juice ? Is it strong enough to set a burl?

[Roy from Pa]

I've never used it.

I use strong solid wood for riser material.

[joebuck]

Oh my bad Roy, I thought from your response , you had some experience with Cactus Juice. Definitely a poor choice on my part for wood. Cactus Juice did not turn out to be my snake oil    heres a disc out same material. Somehow I got to get a riser out of this material. 

[kennym]

How bout something like this Joey? 1/4" scales
On a phenolic core I beam ?


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[kennym]

That's a 1 pc but will work same on a TD, I got a couple of them, not as handy to get a pic of...