IPE selfbow

[traditionalman]

I'm making a IPE self bow with bamboo backing. The bow is 1 and 1/4 wide and 66 inches nock to nock. The bamboo backing is 1/8 thick and the IPE is 3/8 thick back to about 12 inches from handel and then it is 7/16.

Never had a IPE bow come out yet they all broke in the tillering process. However if this one lives what do you think the poundage would be. I'm not experience enough yet to make a guess. I have worked with hickory but this IPE is different for me.

[John Scifres]

Just to be clear, if you back it, it isn't a selfbow.  It is a composite bow.  A selfbow is the same working material from belly to back.

That being said, your answer lies in your efforts.  It could be anywhere from 40-90#.  1/8" bamboo is probably too thick if you are measuring at the sides.

[traditionalman]

Thanks I'm learning as I go. I thought the Bamboo at 1/8 would be heavy but thought of thinning after I glued it to the IPE. Would this be the wrong thing to do?

[John Scifres]

Is it raw bamboo?  If so, then yes, it is not a good idea.  I don't know about other types of boo.

[Loren Holland]

Gary,
much of my failures with Boo/Ipe was from leaving the boo too thick. If you don't taper it down to 1/16 at the tips, then after tillering you don't maintain a good ratio of bellywood to backing. my last several bows, i started stopping just short of knife edgeing the boo,then cut it match the limb width taper,(now you will see that the boo appears thicker at the ends, its an illusion, its just that now you only see the center portion of the boo) and then go back taper the ends to maintain the same look on the edges from middle to tips, this will insure it is tapered.
Get the Ipe bending some first, then perry reflex the glue up of the backing.
John was absolutely right, onced you put on raw boo on the back you can't thin it. in fact be very careful about sanding the nodes and scraping the rind off.
You can however sand laminated boo. In the last bow i posted Sam Harper showed me how to glue on a trilam of processed boo, so that i could sand it. I used the third layer to take the weight back up on a bow that i had hinged and had to even it out.

[DogVilleDane]

Gary,

I have had a great help from reading Sam Harpers build along of his Ipe/Boo bow. It has saved me from countless errors    

It is located at:

 Sam Harpers PoorFolkBows

[traditionalman]

I was wrong about the Bamboo backing it turned out to be Hickory. When I bought it off a guy he told me  it was Bamboo but upon questioning him futher it is Hickory.

[John Scifres]

OK then yes, you can thin it after backing but you probably won't need to.  The backing should not comprise more than 25% of the thickness.