Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: razorsharptokill on April 24, 2022, 06:38:38 AM

Title: Bamboo backed Osage longbow
Post by: razorsharptokill on April 24, 2022, 06:38:38 AM
I have had this bow near completion for years. I recently picked it back up. It seems that every bow I build where I glue a handle piece on, one or both ends lifts slightly on the fade. A slight flex must be occuring there. I used titebomd III. Would a two part epoxy prevent this?

This one is 64 1/4" NTN and will be just under 40 lbs at 28" I believe.
Title: Re: Bamboo backed Osage longbow
Post by: Flem on April 24, 2022, 09:27:16 AM
Have you tried thinning the fades more than you are currently?
I don't use TB3, but I'm guessing its not as tenacious as EA-40
Title: Re: Bamboo backed Osage longbow
Post by: Pat B on April 24, 2022, 09:52:52 AM
The handle area looks thick enough to not bend. Like Flem said maybe reduce the length on the riser a bit to see if that helps. I've attached many handle risers and the only ones that failed were ones that did bend even slightly.
 One thing you can do is remove that riser and make up another riser with multiple layers of thin material.
Title: Re: Bamboo backed Osage longbow
Post by: flntknp17 on April 25, 2022, 11:33:17 AM
One other easy way to stop the handles popping off is to use a slim powerlam that is a little longer than the fade-to-fade length.  It will naturally stiffen the handle and stop them from lifting.  I used TB3 for 10+ years before I converted to EA-40 and the powerlam completely stopped any handle issues once I started using them.

Matt
Title: Re: Bamboo backed Osage longbow
Post by: razorsharptokill on April 25, 2022, 08:20:31 PM
Thanks guys! I finished the tillering and it pulls 41lbs at 26"
Title: Re: Bamboo backed Osage longbow
Post by: Bowjunkie on April 28, 2022, 07:28:29 AM
I don't jump through those hoops... powerlams, multiple thin lams, or pedestals, and I never have anything lift. After the pieces are fit together as well as I can get them, I groove all gluing surfaces with a fine tooth toothing plane blade, just held by hand like a scraper and worked until the grooves are full depth of the teeth(they're actually very shallow). Run the blade lengthwise down the entirety of both gluing surfaces so all grooves run parallel with the bow's length. Takes like 30 seconds. Then use Smooth On ea40 to wet both surfaces, clamp with moderate pressure, with a shop light nearby for warmth. Whether it bends some into the fades and handle or not, doesn't matter. Quick. Simple. Never comes loose. Impossible to starve a glue joint this way.

Make sure the epoxy is adequately mixed. If not, that can cause delams no matter what methods are used.

I use the toothing plane on the bamboo backing, it's actually how I finish thinning it down, and overlays as well. No more glue joint concerns.

The toothing plane is one of my favorite tools in the shop, but if you don't want to spend the money on a whole toothing plane, and just want a blade to prep gluing surfaces by hand, you can sometimes find them on the big auction site.
Title: Re: Bamboo backed Osage longbow
Post by: Kirkll on April 28, 2022, 02:33:16 PM
36-40 grit sand paper on an edge sander or drum sander= toothing plane results. Sure a lot faster....   Kirk
Title: Re: Bamboo backed Osage longbow
Post by: Buemaker on April 28, 2022, 06:17:08 PM
Hmm
Title: Re: Bamboo backed Osage longbow
Post by: onetone on April 28, 2022, 11:58:10 PM
Interesting Bue