Primitive Archer

Main Discussion Area => Bows => Topic started by: Lee Lobbestael on January 15, 2012, 05:33:57 pm

Title: left bamboo to thick!
Post by: Lee Lobbestael on January 15, 2012, 05:33:57 pm
Well i"m making a bamboo backed hickory r/d bow for my brother in law and Its all glued up and its about floor tillered. I thought I got the bamboo pretty thin but after I reduced the width to an inch and a half I realized that the boo is pretty thick. Its probably a quarter inch thick. Will this overpower the hickory and cause chrysals?  :(
Title: Re: left bamboo to thick!
Post by: Pat B on January 15, 2012, 07:17:11 pm
Lee, trap the sides so the back is narrower than the belly. This will help. Even an inch and a half is too wide for a boo backed bow. 1 3/8" is about right and will allow the boo to have a very thin edge.
Title: Re: left bamboo to thick!
Post by: HickoryBill on January 15, 2012, 08:08:00 pm
Yep what Pat said ;) ;)
Title: Re: left bamboo to thick!
Post by: PatM on January 15, 2012, 10:19:19 pm
Trapping the sides will make the backing appear relatively thicker......
Title: Re: left bamboo to thick!
Post by: Pat B on January 16, 2012, 01:19:35 am
...but lesson the compression stresses on the belly.
Title: Re: left bamboo to thick!
Post by: Lee Lobbestael on January 16, 2012, 09:35:11 am
Ok thanks guys
Title: Re: left bamboo to thick!
Post by: PatM on January 16, 2012, 12:18:38 pm
I guess it depends how crowned the bamboo is. I was going by the reference that the edges would be thin. They would look tapered after trapping but now there is unsupported bamboo "pithy"material exposed on those tapered adges.
 If the bamboo is fairly crowned then that centre ridge is doing most of the work that is "crushing" the belly so reducing the edges won't do THAT much.
 Removing material that is just floating on the edges won't radically change the fact that the center is just too thick. It's certainly worth a try but no guarantee that it will do as much as is hoped for.
Title: Re: left bamboo to thick!
Post by: Lee Lobbestael on January 16, 2012, 06:49:25 pm
Would if I decrowned the back and then backed it with rawhide?
Title: Re: left bamboo to thick!
Post by: Marc St Louis on January 16, 2012, 06:55:51 pm
Would if I decrowned the back and then backed it with rawhide?

No.  Try what PatB said.  When you trap the Bamboo go down into the Hickory a bit
Title: Re: left bamboo to thick!
Post by: Lee Lobbestael on January 17, 2012, 08:26:18 am
How do you guys trap a bow. Just make the cross section look like a trapazoid?
Title: Re: left bamboo to thick!
Post by: Pat B on January 17, 2012, 11:15:33 am
Lee, I start out by rasping the sides of the limb at an angle working(rasping) from back to belly to get the shape I desire then dress it up with a scraper. Be sure to round all corners too.
Title: Re: left bamboo to thick!
Post by: Lee Lobbestael on January 17, 2012, 12:30:53 pm
Trapping should save the bow then?
Title: Re: left bamboo to thick!
Post by: Pat B on January 17, 2012, 12:33:07 pm
It will definately help it along.  ;)
Title: Re: left bamboo to thick!
Post by: Lee Lobbestael on January 17, 2012, 06:29:59 pm
Ok guys it should be a good experiment for me then!
Title: Re: left bamboo to thick!
Post by: Badger on January 17, 2012, 06:46:58 pm
I wouldn't worry too much about the bamboo being thick, the outer part does all the work, the inner part will just act like a core. Not sure how lonh your bow is but if it is around 66" or longer you should be fine, just next time maybe thin it a bit more.