I am building some laminated longbows and wanted to know if having a sixth lam would have any negative effects on it? I've done several 5 lam bows but the lumber I have isn't thick enough to get the poundage I desire.

I don't see a problem. I have put six in before counting veneers.

It's all about stack height. You are effectively not doing anything but turning single pieces into 1 piece. There is a SLIGHT affect due to the additional glue lines, but it's hard to say how much without knowing the design.

Only down side is it gives 2 more points of potential failure, the extra glue lines.

Is that 6 including glass or excluding it?

Not including the glass. I was going to do a Hill style 66" 60#. 4 lams 2 veneers then the glass. My core lumber just isn't thick enough to give me the stack I want so I was going to add a extra one. I just wasn't sure of the side effects of a extra glue line.

Most of my bows like you are describing have 2 glass lams two tapers , two parallels and a matrix center core parallel if either glass or carbon,. So no Six is not too many. Actually the thinner the lams to a degree the less tension is applied to the wood and the longer the bow will last. The way I grind my lams and as tight as the glue lines are I absolutely reject that glue weight will make a difference. Also the only failures I have ever had was prior to the time I started using thin laminations and that was due to the wood itself failing. Not glue lines failing. If you clean every thing good , sand properly and use sufficient pressure and heat in the cooking then you should n0t have lamination failure. God bless and have fun, Steve

You will use more smooth-on,probably mix 9-10oz to be safe. What kinda lam wood ya using.

I didn't think it would be a problem. This bow is going to be all yew.

Nice where did you get the yew?

From curt at Wood vault. I also bought some mango and Myrtle. Beautiful veneers and great customer service. I Highly recommend them.

I can't prove it, but I'm of the opinion that the more glue lines one has, the stiffer the bow acts, or put another way, with two stacks of the same thickness, the one with more glue lines will be a pound or two heavier.

Yew is beautiful stuff.

IMHO A straight style Howard Hill bow will not be as sensitive to thickness as a more high performance type of bow. As long as your total butt thickness (stack) are the same I doubt if the extra glue line is going to matter much. Even if it is a pound or two heavier won't take that much either to dial her in to what you want.

Now with what everyone has said. Lets get some glue mixed up and giiter done! Want pictures too when your finished!!!

Y'all Take Care

Its glue time for Yew

Are yew doing it yewself ;)

Yes I'm doing "yewself". Just put it in the oven.

Depends on the lam material. Glue is heavier than bamboo so more lams would mean heavier, slower limbs.

Not bad for a days worth of work

Craig Ekin of Howard Hill Archery told me once that there was a benefit to 5 or 6 lam bows over 3 to 4 lam bows. Had something to do with the glue lines. Might be in line with what Sixby alluded to. It was years ago and I cannot remember what it was.

Yew'all put her together purty quick. How's her poundage! Looking good so far

I'm right around 60#. I'll put final pics and specs up after I'm done sanding.

Yew should have built that one in Texas, goes faster there I've seen it done ;) looking good man. Jeff F

Jim: the benefit of more thinner lams of BAMBOO is not the additional glue ones, but the ability to incorporate more of bamboo's power fibers which are found in greater amounts near the outside of the raw culn. Six thin lams taken from near the outside of the culn contain more power fibers than three or four thicker laminations which contain more weaker material. That's the argument, anyway. Andit doesn't apply to any other lamination material. As I said before, I think the additional glue lines also add stiffness, but probably not enough so most would notice.

I just need to name it and put specs on. 66"amo 57# @28

Yea did a nice job, congrats on completion. Jeff F

I came up with the name. Thanks for the compliments. Shoots smooth.

That is gorgeous Yew!

Bill

That's too damn funny Tate! Very nice bow and I love yew for cores!

"yew all" take care LMAO!

Great looking bow

Great looking, well made yew lam longbow!.. I like the name also.. YEWPHORIA..:)

IF one uses a good quality epoxy( I use G-2) and looks at the specs for tensile strength, flexural strength, shear strength..IT FAR surpasses any wood bowyers ever use.

Trick is to get a good design..accurate tapers a good glue up and proper cure and THEN the layout and tillering..:)

Interesting that Harold Groves often used a single maple lamination( tapered) with bacvk & belly clas..in some of his best Dyna-Stressed recurves..

With multiple laminations..EVERY lamination must be right, upper and lower limb balanced...prepped and buttered and clamped up well.. A fascinating hobby for certain sure..:) Jim

Thanks for the compliments. I'm very happy with it.

I just counted 13 lams, including tips, on an early 50s Grizzly on another thread.

That's a nice looking bow. Congratulations, I think you have a winner.

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