Grain selection in belly wood

[outdoors4me]

Hey folks,

I'm new to tradgang. I am starting to build traditional long bows. I am glueing up yellow heart belly wood with a bamboo backing.

I'm not 100% sure I have been choosing the right grain patterns in the YH. In the included pic, would you choose the example on the left or the right?

Thanks!

Beck

[BMN]

Left. 1/4 sawn.

[outdoors4me]

BMN,

I'm going to explain why I'm asking this after a few more replies, but suffice it to say I think I am using the wrong orientation.

What do see as the advantage of using quarter sawn?

Thanks,

Beck

[Roy from Pa]

1/4 sawn is what I use.

It's stronger and easier to see runouts.

Think about a ball bat, they are built to hit the ball against the growth rings.

But flat sawn will work as all selfbows are flatsawn oriented.

[attachment=1,msg2821756]

[outdoors4me]

OK, so both of you use 1/4 sawn while I have been using flat sawn.

Here's why I thought something was wrong. My first two bows were from a vendor - already glued up yellow heart and bamboo. I had to remove a pretty good bit of wood to be able to string it up and both shoot great.

My next two bows I glued up myself. I picked out some flat sawn YK, milled it down and glued it with a bamboo backer.

BOTH of these bows I feel that I could almost string them up without removing any wood. Way too mushy.

So I think you guys just corrected my error.

Thanks!

Beck

[Roy from Pa]

I wouldn't blame the mushy bows on only the flat sawn.

It could have been the thickness, width, design, etc.

While 1/4 sawn is stronger, and my choice for laminated bows, every selfbow made is flat sawn.

A selfbow is made from a single stave from a tree, just like the tree grew and nothing glued onto it.

Other bows built from boards, or bamboo, glued together are labeled laminated bows.

[outdoors4me]

Roy,

What has me perplexed me is that it's the same TYPE of wood and the very same design, yet it just doesn't have much backbone.

I took a week long class to learn how to build these things. I traced out the instructor's design, measured the thickness of the wood, etc.

So I was hoping the answer would lie in the grain orientation.

Maybe not?

Thanks,

Beck

[Roy from Pa]

I understand, Beck.

Was the wood dry?

Green wood will be weaker than dry seasoned wood.

No two trees or boards are the exact same strength.

They can and will vary.

But yes, 1/4 sawn is the best and strongest in my opinion.

Just keep making bows and learn as you go.

Keep notes on every bow.

And before you know it, you will be building great bows.

[outdoors4me]

Roy,

Yes the wood was dry.

The only deviation in my instructors method of constructing these bows is that I noticed in his earlier specs, his belly wood was 5/8" thick. The pre-glued bow in the class that I attended and a subsequent pre-glued bow that I purchased from his website, the thickness was 3/8" and both of those had plenty of backbone.

Unfortunately, I cannot ask him any questions. His website was shutdown shortly after our class and the phone number for his business is disconnected. So that sure doesn't sound good.

Thanks for your help!

Beck

[Roy from Pa]

What is flat sawn YK wood?

And 1/8th of a difference in thickness could mean 10 pounds or so.

[outdoors4me]

Oh, sorry. I meant that to be YH, meaning Yellow Heart.

Thanks,

Beck

[Roy from Pa]

Ah I see:)

YH isn't a real strong wood, compared to osage which is what I use.

Make your next bow thicker or wider and see what happens.

I've been doing this for 15 years and still learn new stuff..

[BMorv]

I think you are looking in the wrong place to find the problem here.  As Roy mentions, many bows are made from flat sawn wood.  If the grain is straight, it doesn't matter.
0.003 to 0.006" of thickness difference will equal one pound of draw weight (assuming everything else was the same).  Your thickness is off if I had to make an educated guess.

[outdoors4me]

Thanks Roy!

Ah I see:)

YH isn't a real strong wood, compared to osage which is what I use.

Make your next bow thicker or wider and see what happens.

I've been doing this for 15 years and still learn new stuff..

[outdoors4me]

Thanks BMorv!

I think you are looking in the wrong place to find the problem here.  As Roy mentions, many bows are made from flat sawn wood.  If the grain is straight, it doesn't matter.
0.003 to 0.006" of thickness difference will equal one pound of draw weight (assuming everything else was the same).  Your thickness is off if I had to make an educated guess.

[BMN]

Beck,

Looks like Roy and BMorv have you moving in the right direction. Listen to them, they know what they're talking about.

I have used both flat sawn and 1/4 sawn in BBO's with success. I like to heat bend the tips before glue up to add a little more reflex and have had flat sawn boards pop a splinter while doing this. So far it hasn't been fatal but for this reason if I have a choice I will pick a 1/4 sawn board.

Bill

[outdoors4me]

Thanks Bill !

Beck,

Looks like Roy and BMorv have you moving in the right direction. Listen to them, they know what they're talking about.

I have used both flat sawn and 1/4 sawn in BBO's with success. I like to heat bend the tips before glue up to add a little more reflex and have had flat sawn boards pop a splinter while doing this. So far it hasn't been fatal but for this reason if I have a choice I will pick a 1/4 sawn board.

Bill

[Mark Smeltzer]

My opinion.
Your idea about a longer bow being smoother and more accurate is mostly right but you will give up a performance if you don't load the limbs appropriately. You can do this with a longer riser/less working limb but you may not like that tiller profile and the way it draws and shoots.
I use multiple lams in my backed wooden bows for two reasons.
I can and do use quarter sawn lams in the cores for good stability, consistency and speed but on the very belly I will lay a flat sawn lam for it's looks, much of this flat sawn lam is tillered away but you still get the look of flat sawn lumber.
Second reason is because multiple laminates glued together will maintain their profile and not end up straight as you were told.
Osage is a great choice as is Yew, Red Elm, Hard Maple, Hickory and quite a few others. I don't have any experience with Choke Cherry.
As others have said there isn't anything really wrong with flat sawn lumber for a bow......I like the selfbow analogy...they are all flat sawn but in a laminated bow you have the option to use quarter sawn and I do feel it's a bit more stable because of the orientation of the rings.

[outdoors4me]

Thanks Mark.

My opinion.
Your idea about a longer bow being smoother and more accurate is mostly right but you will give up a performance if you don't load the limbs appropriately. You can do this with a longer riser/less working limb but you may not like that tiller profile and the way it draws and shoots.
I use multiple lams in my backed wooden bows for two reasons.
I can and do use quarter sawn lams in the cores for good stability, consistency and speed but on the very belly I will lay a flat sawn lam for it's looks, much of this flat sawn lam is tillered away but you still get the look of flat sawn lumber.
Second reason is because multiple laminates glued together will maintain their profile and not end up straight as you were told.
Osage is a great choice as is Yew, Red Elm, Hard Maple, Hickory and quite a few others. I don't have any experience with Choke Cherry.
As others have said there isn't anything really wrong with flat sawn lumber for a bow......I like the selfbow analogy...they are all flat sawn but in a laminated bow you have the option to use quarter sawn and I do feel it's a bit more stable because of the orientation of the rings.

[Roy from Pa]

Beck, when you glued up the last two bows.

Are they bend through the handle bows?