Purple Heart vs IPE

[LaBill67]

Ok all you experienced boyers out there.  Has anyone ever tried using purple heart for belly wood with an overlay of bamboo or hickory? IPE and purple heart seem similar when comparing their wood data specs.

[LittleBen]

Going strictly by the numbers, Ipe is 10% stiffer than purple heart, and ~8% more flexible. Ipe is also nearly 20% more dense.

On that analysis, you should be able to make your Purple Heart bow 20% wider than you would for ipe, and roughly 10% thinner back to belly and you should be in the ballpark.

I have never used purple heart, but have used a lot of ipe, and I have successfully used wood database to estimate the dimensions for alternative belly woods based on my Ipe designs.

I will say though, Purple Heart has a reputation for being brittle, suffering from compression fractures, and being extremely difficult to work ... although Ipe is a bear to work also.

[LaBill67]

Originally posted by LittleBen:
Going strictly by the numbers, Ipe is 10% stiffer than purple heart, and ~8% more flexible. Ipe is also nearly 20% more dense.

On that analysis, you should be able to make your Purple Heart bow 20% wider than you would for ipe, and roughly 10% thinner back to belly and you should be in the ballpark.

I have never used purple heart, but have used a lot of ipe, and I have successfully used wood database to estimate the dimensions for alternative belly woods based on my Ipe designs.

I will say though, Purple Heart has a reputation for being brittle, suffering from compression fractures, and being extremely difficult to work ... although Ipe is a bear to work also.

[LaBill67]

The compression fracture problem could be a major detractor. Is that a problem to deal with when using IPE?

[Pat B]

Ipe will fret too but not as easily as purple heart.

[Buemaker]

It is better to use PH as a center lam in a tri lam bow. In that capacity it is used quite a lot.

[LaBill67]

Thanks everyone for the replies.  You have sparked some additional interest in me now concerning tri lams. I have in my shop PH, cherry, walnut, maple and some birch.  Would any that be good for a tri lam and if so what combinations and thicknesses would be good?

[Mad Max]

Originally posted by LittleBen:
Going strictly by the numbers, Ipe is 10% stiffer than purple heart, and ~8% more flexible. Ipe is also nearly 20% more dense.

On that analysis, you should be able to make your Purple Heart bow 20% wider than you would for ipe, and roughly 10% thinner back to belly and you should be in the ballpark.

I have never used purple heart, but have used a lot of ipe, and I have successfully used wood database to estimate the dimensions for alternative belly woods based on my Ipe designs.

I will say though, Purple Heart has a reputation for being brittle, suffering from compression fractures, and being extremely difficult to work ... although Ipe is a bear to work also.

Ben
Post some of your bows for us to see.    
Thanks

[Roy from Pa]

I have a purple heart board. I'll use it for a core lam or riser, but not a belly lam.

[LaBill67]

Originally posted by Roy from Pa:
I have a purple heart board. I'll use it for a core lam or riser, but not a belly lam.

So Roy, how does this sound for a tri lam, walnut belly, PH core, and cherry back with a cherry riser?

[LaBill67]

Originally posted by Mad Max:
 

Originally posted by LittleBen:
Going strictly by the numbers, Ipe is 10% stiffer than purple heart, and ~8% more flexible. Ipe is also nearly 20% more dense.

On that analysis, you should be able to make your Purple Heart bow 20% wider than you would for ipe, and roughly 10% thinner back to belly and you should be in the ballpark.

I have never used purple heart, but have used a lot of ipe, and I have successfully used wood database to estimate the dimensions for alternative belly woods based on my Ipe designs.

I will say though, Purple Heart has a reputation for being brittle, suffering from compression fractures, and being extremely difficult to work ... although Ipe is a bear to work also.

Ben
Post some of your bows for us to see.        
Thanks [/b]

[LittleBen]

Originally posted by Mad Max:
 

Originally posted by LittleBen:
Going strictly by the numbers, Ipe is 10% stiffer than purple heart, and ~8% more flexible. Ipe is also nearly 20% more dense.

On that analysis, you should be able to make your Purple Heart bow 20% wider than you would for ipe, and roughly 10% thinner back to belly and you should be in the ballpark.

I have never used purple heart, but have used a lot of ipe, and I have successfully used wood database to estimate the dimensions for alternative belly woods based on my Ipe designs.

I will say though, Purple Heart has a reputation for being brittle, suffering from compression fractures, and being extremely difficult to work ... although Ipe is a bear to work also.

Ben
Post some of your bows for us to see.        
Thanks [/b]

I don't wanna hijack this thread.
I'll post some here shortly. It's brutal trying to use Photobucket on my iPad.
 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=125&t=014244#000002