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Main Boards => The Bowyer's Bench => Topic started by: outdoors4me on September 26, 2018, 09:33:05 AM

Title: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 09:33:05 AM

Hey folks,

New builder here trying to trace down a problem with my bows not having enough backbone coming straight off my glue up form.

What thickness do you start with on your belly wood? I know this could vary with type of wood. In my case, I'm using Yellow Heart backed with bamboo.

I've already made another post about wood grain orientation as well.

Thanks much!

Beck

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Pat B on September 26, 2018, 09:36:02 AM

I personally wouldn't start with less than 5/8" thick unless you plan on using a power lam.
FYI, a power lam goes between the back and the belly at the handle to keep the handle area rigid.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 09:45:06 AM

Thanks Pat!

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: BMorv on September 26, 2018, 09:49:34 AM

I've worked with YH a good bit.  Pat is right on with thickness.  I would start at 5/8".  Mine usually finish out right under 1/2" thick, but that can obviously vary with your design. 

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 10:10:25 AM

5/8" inch it is!

Thanks,

Beck

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 10:11:23 AM

Yup, 1/2 to 5/8th for YH.

Osage I did 7/16th to 1/2.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 10:19:19 AM

OK, here is the reason why I asked....

I recently took a class on building longbows.

The instructor gave us a bow(stave) in class that was already glued up. 3/8" piece of yellow heart glued to a piece of bamboo. It had plenty of backbone and I ordered another just like it from his web site after the class and it had plenty of backbone.

I noticed in his earlier published plans that he USED to use 5/8" thick Yellow Heart. So I wonder if he can tell by looking at the wood before it is  cut as to how strong it's going to be.

The reason I'm stumbling through all of this is by all signs (website down, phone disconnected) he is out of business. I can no longer reach him for answers.

So I thank everyone for their help here.

Beck

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 10:26:00 AM

Were the first 2 bows from him 1/4 sawn?

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 10:41:51 AM

Roy,

Unfortunately I don't know and I can't ask him. Those two bows are finished and I can't really look at the grain on the end to be able to tell.

Is there another way just looking up and down the bow to tell?

Thanks, Beck

Quote from: Roy from Pa on September 26, 2018, 10:26:00 AM

Were the first 2 bows from him 1/4 sawn?

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: BMorv on September 26, 2018, 10:50:14 AM

I don't see how a decent weight bow was made from a .375" thick peice of YH.  Do you have pics of both bows? 

This bow came out 45 #'s and started out .550" right out the fades.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 10:57:39 AM

Looking at the belly of the bow, the side facing you when shooting.

1/4 sawn will have long straight growth rings running the length of the limbs.

Flat sawn will look like arrowheads.

 [ You are not allowed to view attachments ]

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 11:02:22 AM

1/4 sawn board on right side.

 [ You are not allowed to view attachments ]

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Pat B on September 26, 2018, 11:06:18 AM

I've never used yellow heart but I always start out thicker and reduce the thickness as I tiller the bow. That way I'm assured I achieve the draw weight and proper tiller I desire.  I don't make many backed or trilam bows so I'd rather air on the side of safety starting with a thicker piece of belly wood than someone that makes these bows on a regular basis, like Roy and others.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:21:51 AM

Trying to post pics but it won't let me. Not sure if it's the size or what. I'll keep trying....

Quote from: BMorv on September 26, 2018, 10:50:14 AM

I don't see how a decent weight bow was made from a .375" thick peice of YH.  Do you have pics of both bows? 

This bow came out 45 #'s and started out .550" right out the fades.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:23:34 AM

Thanks Pat!

Quote from: Pat B on September 26, 2018, 11:06:18 AM

I've never used yellow heart but I always start out thicker and reduce the thickness as I tiller the bow. That way I'm assured I achieve the draw weight and proper tiller I desire.  I don't make many backed or trilam bows so I'd rather air on the side of safety starting with a thicker piece of belly wood than someone that makes these bows on a regular basis, like Roy and others.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:24:15 AM

Wow, that's certainly easy to see.

Thanks Roy!

Quote from: Roy from Pa on September 26, 2018, 11:02:22 AM

1/4 sawn board on right side.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 11:24:32 AM

If using a cell phone for pictures, you need to go into the phones camera settings and choose the smallest size picture it take.

Cell phones take humongous size pictures for some reason..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:34:07 AM

Ah! I'll reduce them in Lightroom and try again.

Thx

Quote from: Roy from Pa on September 26, 2018, 11:24:32 AM

If using a cell phone for pictures, you need to go into the phones camera settings and choose the smallest size picture it take.

Cell phones take humongous size pictures for some reason..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:40:00 AM

These both started out as 3/8" and now are about 5/16". Hard to believe, but I can't even string the one finished in oak without a stringer device. The purple one I can barely string on my own.

Beck

Quote from: BMorv on September 26, 2018, 10:50:14 AM

I don't see how a decent weight bow was made from a .375" thick peice of YH.  Do you have pics of both bows? 

This bow came out 45 #'s and started out .550" right out the fades.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 11:40:37 AM

Ya know there will be a $19.99 fee for all this info, don't ya?

LOL Just kidding..

 :wavey:

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 11:42:57 AM

Roy,

The bows(staves) that I got from my instructor definitely look straight grained (1/4 sawn). The ones I picked out from my local supplier were flat sawn for sure. He showed me the cathedrals - which you call arrowheads.

Thanks,

Beck

Quote from: Roy from Pa on September 26, 2018, 10:57:39 AM

Looking at the belly of the bow, the side facing you when shooting.

1/4 sawn will have long straight growth rings running the length of the limbs.

Flat sawn will look like arrowheads.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 11:54:49 AM

Ok, that and them not being thick enough are the reason for the lighter weight.

But hey, finish them up and give to a kid to shoot.

Also:
You posted a thumbnail picture, which is fine.

After you select your picture from your PC or phone, just to the right of the little window where the picture name appears, click ( Insert Attachment 1 ). That will make the picture full size in your post.

 [ You are not allowed to view attachments ]

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 12:17:58 PM

Ha! Well, I sure to appreciate it!

Thanks.

Quote from: Roy from Pa on September 26, 2018, 11:40:37 AM

Ya know there will be a $19.99 fee for all this info, don't ya?

LOL Just kidding..

 :wavey:

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 12:20:46 PM

Hey guys,

I really appreciate all the info. Losing the access to my instructor really left me scratching my head. After all of your input, I feel I have a good baseline to start over do it right.

Thanks again!

Beck

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 12:21:35 PM

Great idea to turn them into a kids bow!

Thanks!

Quote from: Roy from Pa on September 26, 2018, 11:54:49 AM

Ok, that and them not being thick enough are the reason for the lighter weight.

But hey, finish them up and give to a kid to shoot.

Also:
You posted a thumbnail picture, which is fine.

After you select your picture from your PC or phone, just to the right of the little window where the picture name appears, click ( Insert Attachment 1 ). That will make the picture full size in your post.

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: BMorv on September 26, 2018, 12:26:58 PM

Hmm.  Bamboo looks pretty thick?  Bendy handle bow?  Sorry I assumed you were talking about a typical stiff handled bow.  I can't help you much with dimensions if it's a bendy. 

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 12:33:25 PM

WOW, I'll say the boo is thick...

I didn't notice that in the small picture..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 12:36:52 PM

I'll have to go back and measure the bamboo, but I know it's supposed(according to instructors specs) to be 1/8".

Thanks, Beck

Quote from: Roy from Pa on September 26, 2018, 12:33:25 PM

WOW, I'll say the boo is thick...

I didn't notice that in the small picture..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 12:43:50 PM

I'll have to go back and measure the bamboo, but I know it's supposed(according to instructors specs) to be 1/8".

Yup 1/8th...

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Fishinglink on September 26, 2018, 05:51:37 PM

Beck, glad to see you made it over here. Looks like you’re getting the answers you needed.


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Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 05:59:10 PM

OH?

So you are the one who sicked him on us?

LOL

We will get him headed in the right direction..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Fishinglink on September 26, 2018, 07:36:20 PM

He was getting no where on AT so I thought you guys could help him out a bit. It was far above my pay grade.


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Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: Roy from Pa on September 26, 2018, 07:47:40 PM

He is in the right place now..

Title: Re: Thickness of Belly Wood - when glueing wood to bamboo backing
Post by: outdoors4me on September 26, 2018, 09:54:45 PM

Thanks Fish!

Quote from: Fishinglink on September 26, 2018, 05:51:37 PM

Beck, glad to see you made it over here. Looks like you’re getting the answers you needed.


Sent from my iPhone using Tapatalk