Primitive Archer

Main Discussion Area => Bows => Topic started by: Corvus on May 10, 2020, 10:55:59 pm

Title: Red oak siyahs
Post by: Corvus on May 10, 2020, 10:55:59 pm
Think I might use the extra board of red oak to spice up my all maple cores in my upcoming projects. That or I make a couple sinew backed red oak bows, at which point I would wonder if I should trap to widen the belly or if I should add a lam to the belly. Not much experience with red oak, so not sure how worried need to be about compression failure if doing the sinew backed bows instead of chopping it into siyahs
Title: Re: Red oak siyahs
Post by: StickMark on May 11, 2020, 01:51:49 pm
The issue of compression with sinew backed hickory is similar. I think I recall going too wide on hickory and sinew invites trouble; it did for me.
Title: Re: Red oak siyahs
Post by: willie on May 11, 2020, 01:57:16 pm
Stick,
I assume you went as wide on the back with the sinew as the  belly?  How thick was the sinew compared to the thickness of the hickory on the one that gave trouble?
Title: Re: Red oak siyahs
Post by: Corvus on May 11, 2020, 02:45:51 pm
Stick,
I assume you went as wide on the back with the sinew as the  belly?  How thick was the sinew compared to the thickness of the hickory on the one that gave trouble?
I would be curious to know as well. Also why I wondered if trapping the back so the belly is wider would be viable to keep the sinew backing from causing compression failure or if I should just lam the belly with something that is compression strong. Doubt I will have any horn left after the main projects, but have a lot of sinew to toss on a couple extra bows from the spare board
Title: Re: Red oak siyahs
Post by: willie on May 11, 2020, 03:22:51 pm
Quote
I wondered if trapping the back so the belly is wider would be viable to keep the sinew backing from causing compression failure

Trapping seems to make sense if the sinew is getting the job done, and you want to minimize excess weight, at least up to the point where excessive trapping causes stability issues.

Stability, of course, also depending a lot on the limb recurve geometry.
Title: Re: Red oak siyahs
Post by: PatM on May 11, 2020, 04:07:45 pm
Sinew does not cause compression failure directly.
Title: Re: Red oak siyahs
Post by: Corvus on May 11, 2020, 04:21:53 pm
Sinew does not cause compression failure directly.

Not directly, but with regards to red oak I am not sure how well it's compression strength holds up when adding extra tension. Why I asked if I should be adjusting the belly side to compensate that as I am not familiar with red oak. I am likely just going to use half the board for siyahs and other half make 2 billets for something else and just play with some ideas