Power lam

[DC]

What is the reasoning behind a power lam? Why not just make either the belly or back thicker in that area?

[Bryce]

Whenever I used a power-lam it’s usually Bc my stock is too thin to keep from bending and popping off the handle riser. With the power-lam it makes the handle area stiff enough to not move.

[bownarra]

Many ways to skin a cat.
It doesn't matter how you make the area thicker from a mechanics point of view as long as it is 'thick enough'.
A thicker belly lam is more wasteful of belly stock.
A thicker backing can be awkward with boo and not too easy when grinding hickory etc...
A powerlam is quite easy and quick to make if you have a drum sander. Make a short taper sled, half length. Grind a pair of lam on this then lap splice them together. Feather the ends for an inch. There you go. I can make one in about 20 mins now. Plus they can be made to look sharp

[DC]

Thanks guys. I figured as much but I thought I'd check.

[silent sniper]

DC, my use of power lams comes out of necessity. I have had a bunch of laminate bow failures from handles popping or the bows cracking in the center from too thin of laminations.These issues happened even with the use of the best epoxy glues. Once I started using a power lam these issues stopped immediately. I must also note that my laminations are made in the .001-.002 consistent taper fashion like glass bow laminations.

I will say that I don't think the power lam used today was invented until the advent of glass bows. I have studied old laminate bows from the 1930s-1940s and none of these have power lams that I have seen. 

I would like to know how the builders of those early 1900's laminate bows made their bows without the use of power lams especially considering the glue technology of the day. Figuring out their tricks is something I am trying to work towards figuring out.

Cheers,
Taylor

[Del the cat]

I think whoever coined the term "power lam" did the bow building community a huge disservice.
"Riser lam" "base lam" or "fade lam" would IMO all be preferable.
Del

[DC]

I think whoever coined the term "power lam" did the bow building community a huge disservice.
"Riser lam" "base lam" or "fade lam" would IMO all be preferable.
Del

Yessir! 

[bownarra]

DC, my use of power lams comes out of necessity. I have had a bunch of laminate bow failures from handles popping or the bows cracking in the center from too thin of laminations.These issues happened even with the use of the best epoxy glues. Once I started using a power lam these issues stopped immediately. I must also note that my laminations are made in the .001-.002 consistent taper fashion like glass bow laminations.

I will say that I don't think the power lam used today was invented until the advent of glass bows. I have studied old laminate bows from the 1930s-1940s and none of these have power lams that I have seen. 

I would like to know how the builders of those early 1900's laminate bows made their bows without the use of power lams especially considering the glue technology of the day. Figuring out their tricks is something I am trying to work towards figuring out.

Cheers,
Taylor

Simple - they just let the belly lam thicker.
If you wanted to carry on making lam bows without a powerlam or thicker belly lam you just needed to make the riser sit between the lams. Have one or two lams go up the riser fade.
This way is arguably 'the best' way to do things. That is why most glass bows are built like that. Zero chance of anything 'popping' and it gives the best look.  Quite bit more complicated than the standard wooden bow way of just gluing a lump on top of the limbs though hence why you very very rarely see wooden bow makers going down that route..