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Main Boards => The Bowyer's Bench => Topic started by: wood carver 2 on January 16, 2017, 04:40:00 PM

Title: Core lam.
Post by: wood carver 2 on January 16, 2017, 04:40:00 PM

I've been planning to build a tri-lam recurve with bamboo for the back and belly and a tapered hardwood core lam, but I'm not sure what wood will take the curve near the tips without breaking. I would like to use maple. The area with the most extreme curve will be about 1/16 of an inch thick. Can it be pre bent using dry heat before glue-up? I am planning to bend the bamboo to the curve as well and I think that I'll add a thin tip wedge for the last 6 or 8 inches.
Dave.

Title: Re: Core lam.
Post by: Bowjunkie on January 16, 2017, 05:02:00 PM

Yes, prebending them with heat can be done and tends to make the limb act more static than those simply held in shape by the glue up. Depends on what kind of limb action you want I guess.

Title: Re: Core lam.
Post by: wood carver 2 on January 16, 2017, 06:09:00 PM

It might be better if the tips are a little stiff. This bow will likely take a fair bit of set and I don't want the tips to flatten out.
I hope it works out.    :pray:  
Dave.

Title: Re: Core lam.
Post by: Roy from Pa on January 16, 2017, 06:20:00 PM

I do that all the time with 1/4" Osage.

Title: Re: Core lam.
Post by: wood carver 2 on January 16, 2017, 09:52:00 PM

I was just unsure if maple could take an extreme bend without breaking. I want to use maple because I have it in the riser and anything else might look funny.
I will be doing the glue-up in stages so a failed limb won't be a big problem.
Dave.

Title: Re: Core lam.
Post by: mikkekeswick on January 17, 2017, 02:06:00 AM

It is not the species more that the grain is straight.

Title: Re: Core lam.
Post by: die_dunkelheit on January 17, 2017, 02:35:00 AM

How much of a bend are we talking about? As thin as you mention could be heat or steamed into a circle. Just use a fiberglass lam or a piece of flashing as a backer when you bend it so it won't break or lift any grain.

Title: Re: Core lam.
Post by: KenH on January 17, 2017, 07:10:00 AM

Standard recurve type curve?  1/8" maple should take that bend without any problem.  But wet or dry preshaping will certainly help things along and give hone those skills.

Title: Re: Core lam.
Post by: Wolftrail on January 17, 2017, 11:25:00 AM

Quote

Originally posted by wood carver 2:
I was just unsure if maple could take an extreme bend without breaking. I want to use maple because I have it in the riser and anything else might look funny.
I will be doing the glue-up in stages so a failed limb won't be a big problem.
Dave.

I use maple all the time, most older FG recurves used maple as the core.  And I can easily bend dry hard rock Maple with a heat gun.

Title: Re: Core lam.
Post by: wood carver 2 on January 17, 2017, 04:18:00 PM

Thanks guys. I'll be starting the limbs as soon as the weather gets better. It's supposed to be pretty nice on the weekend.
Dave.

Title: Re: Core lam.
Post by: LittleBen on January 17, 2017, 08:48:00 PM

For my pressure strips I use either hard maple or white oak because I know they will take whatever bend I need them to.

So yeah, maple will definately bend as you need.