Safe thickness of window?

[styksnstryngs]

Hey guys, I'm drawing out plans for a TD longbow and I wanted some input about safety. The riser is a slim riser, like a pronghorn or similar riser. I'm planning on sandwiching walnut, 1/4" phenolic, glass, 1/4" phenolic, and walnut. Do you think I could cut 3/16" past center on a 1.5" wide riser?

[Crooked Stic]

Phenolic and wood expand and contract at different rates. If you must use it for accents be sure to rough the glue surfaces good .36 grit or even a hacksaw blade. You better choice would be a stronger wood with the walnut such as a osage ibeam. Also glass overlays on the front of the riser.

[mikkekeswick]

The key is just making sure you get the walnut dry enough first.
Personally I would use a glass or carbon I-beam if you want to cut so far past center. With the combo you have I would go to centre and no further.

[Crooked Stic]

Another thing would be to get you walnut stabilized.

[styksnstryngs]

Alright, the thing is, I really can't use an I beam because of a limit of tools I have. If I have to, I will, probably using three pieces of core tuff, but I would prefer not to. Would five or six pieces of .030 core tuff as accent strips work?

[Roy from Pa]

I'd go for it. What weight bow?

[styksnstryngs]

Probably 45# or less, nothing too heavy.

[styksnstryngs]

How strong would a 1/4" phenolic  I beam be?

[Roy from Pa]

It will be fine then.

[jess stuart]

Coretuff on the back of the riser will help a bunch.  Also be sure you radius the site window junction well.  While walnut is a very pretty wood it isn't the strongest, I would never personally use walnut and cut 3/16" past center.  I assume you are building your bow 1.5" wide so, the window would be 9/16" thick.

[Crooked Stic]

You can use the wood accents. They can be oriented in the width also. The phenolic will be plenty strong just ruff up the glue surface really good. And be sure the MC on the walnut is low. Be sure you get a good seal on the riser after done.

[LittleBen]

Everyone likes to ask "how heavy is the bow?" Or "how far part center?". But remember, the longer the bow, the more stress that is on the riser. So what would be safe for a 56" bow might not be for a 70" bow.

Just my .02

I've never had a bow fail at the shelf/window and Ive cut many to center or slightly past with all wood risers on all wood bows up to 65# and 68" with 1.5" width. So personally i say go for it! What fun is it to live by strict rules?

Live free or die.

[BenBow]

I add additional wood and glass to the outside of the window equal to the amount past center the window is cut. Plus I put .030 glass between 5/16" hickory and locust lams and .030 glass and 1/16" phenolic between the back and belly halves. And this is a very thin riser that's 1 1/16" wide at the pads and is cut 1/4" past center. It's very solid.