power lam question

[Duffy]

I am making a white oak backed ipe bow. Ipe isn't thick enough to taper to keep my riser from popping off so I thought I would try a power lam. Does the lam have to go between the backing strip and the ipe or could it go on after the backing strip? With an eight inch handle how long would the lam need to be?

[Pat B]

Duffy, I've never used one but I believe for best results the power lam goes between the back and belly. I think I'd make it taper out about 4" to 6" each direction past the handle.

[okie64]

Duffy, I always put mine between the back and core.  How far you run it past the handle kinda depends on how thick you make it. If its 1/4" thick in the center do like Pat said. Just remember the longer you go with it the shorter you are making your limbs.

[Duffy]

Thanks for the info guys. Would putting thin lams in the handle section work just as well? And if so, how thin would they need to be for an eight inch handle?

[NTD]

No, even with thin handle lams you can pop them off.  I would definitely go for a power lam.  Plus they help make the riser pretty  

[okie64]

Im with NTD on this one, I think if you use a contrasting color for the powerlam it makes the riser look really good. Not sure how you are going to contrast between white oak and ipe though? Maybe cherry or osage?

[No-sage]

I've never used a power lam in any of my backed bows.  I haven't had a handle pop off in many years now.  They aren't a necessity.

I do sometimes use several thin lams to build up the handle area, usually 1/4 thick.

[NTD]

No-sage, How thick are your cores?  

I can't imagine getting away without a powerlam when your core is 3/8" thick  :rolleyes:

[No-sage]

I make my cores 7/16"

[7 Lakes]

What kind of glue are you using that a glue line just pops apart.  Titebond?

[NTD]

I use Urac.  It's pretty well accepted that it doesn't matter what kind of glue you use, if you use a thin core that is bending through the handle and don't mitigate it with a powerlam you will get lift on the handle lams.

[Duffy]

Mike,

  I have been using titebond 3. In my limited experience, it has worked very well. My backings have not delammed but my riser popped off. I think it was because I had very little taper into the limb and it must have been flexing in the handle area.

[Pat B]

Can you post pics of your bow and handle area?

[Duffy]

Can't do pics yet Pat, but I'm working on it.