Primitive Archer

Main Discussion Area => Bows => Topic started by: Blaflair2 on October 30, 2014, 12:51:53 am

Title: Bendy handle bbi dimensions, also kerfing
Post by: Blaflair2 on October 30, 2014, 12:51:53 am
So last piece of full length ipe, so I really want this to work out lol. Dimensions and maybe a sketch would be sweet. 29" draw. Would like 65ish pounds. In the ~60" range  >:D O:)

Also, I have a table saw, so I was wondering if I kerf it 5", how much of a radius would be reasonable? Also how thick should I make it when attempting the bend? I just want the very tips to be bent more or less. Thanks
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: bubby on October 30, 2014, 01:07:18 am
Your going to have a wide gap to deal with, I think your better off thining the tips enough to get them flipped like you want and glue on a underlay, or glue a piece on the back and cut the re urve in, on a kerf you want the saw kerf as narrow as possible
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Blaflair2 on October 30, 2014, 01:10:07 am
It's a 1/8" blade. I can't just fill it with an 1/8" slat?
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: bubby on October 30, 2014, 01:20:08 am
sure you can, but you cut the kerf with a round blade so you don't get a flat bottom and that is a bear to clean up, I do a lot of glueups and hate ugly glue lines but it's your bow, if you have to do a kerf cut get your hands on one of those Japanese pull saws they make a great cut
don't go more than a 1 1/4" wide straight out to about a ft from the tips and taper from there to 1/2 '
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: mikekeswick on October 30, 2014, 03:33:34 am
Also use a lot of cuts - ipe does not like to bend into recurves. The last one I did had cuts spaced about 1mm apart to get the ipe thin enough. You also have to think about getting even squeeze out which doesn't happen if the wood left is to thick.
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: DC on October 30, 2014, 01:06:14 pm
Is there a build-a-long that shows kerfing? The only kerfing I've ever seen is crossways, like making forms for pouring concrete with curved edges. Somehow that just doesn't seem right for a bow.
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Blaflair2 on October 30, 2014, 01:14:51 pm
U cut down the tip of a bow or stave parallel to the back and belly. And use a shim to fill the kerf and glue in bend.
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: DC on October 30, 2014, 01:22:26 pm
So you end up with a laminated tip. got it! Thanks
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: DarkSoul on October 30, 2014, 02:29:25 pm
Here's an example of a kerf bend recurve I did in an ash bow. The dark line is the thin strip of dark veneer I glued in the kerf that I cut using a regular hand saw.

(http://i30.photobucket.com/albums/c316/JorikSwier/Ash%20paddlebow/P1000674.jpg)
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: DC on October 30, 2014, 02:39:22 pm
Cool, thanks. I've learned something today. I was worth getting out of bed ;)
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Prarie Bowyer on October 31, 2014, 09:31:26 pm
Kerf cut them with a band saw.  I used to do 7" and go nearly 90 deg around paint can dia.  Fill the gap with a sliver of wood.

I use sanding blocks of 50 grit paper to clean up the slivers.  You could cut the kerfs with a fine cut ripping saw (you tube the method) or ryoba saw.  That might be best actually.  A bandsaw will need to have the cut cleaned up.  I just put pieces of the same 59 grit sanding belt in the kerf an the pull it out while squeezing....but the hand saw would leave a cleaner cut.

(http://i235.photobucket.com/albums/ee59/scottnlena/IMG_5437.jpg) (http://s235.photobucket.com/user/scottnlena/media/IMG_5437.jpg.html)

Ipe likes to be longer bows IMO.  I'd go for 64" or longer tip to tip.
If it is narrower I'd also use a level taper for as long as possible.

(http://i235.photobucket.com/albums/ee59/scottnlena/IMG_3705.jpg) (http://s235.photobucket.com/user/scottnlena/media/IMG_3705.jpg.html)

https://m.youtube.com/watch?v=mBN6eSwTi00


Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Prarie Bowyer on October 31, 2014, 09:41:34 pm
The smaller the diameter the thinner you'll need to cut it but you can glue on an underlay.  It doesn't take much ipe to make a heavy bow.  The top curve was 1/2"  so I Krefed it twice.  The bow above was about a quarter inch thick before the kerf cut.
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: bubbles on November 01, 2014, 07:17:26 pm
So with a kerf bend, the only thing holding the recurve in is the glue-up?  There is no steaming/heat bending involved? Just curious.

Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: wizardgoat on November 01, 2014, 07:44:56 pm
wow ive actually never seen this, its very cool. looks like something i would mess up horribly though,
i'll stick to my pot of boiling water for now haha
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Blaflair2 on November 01, 2014, 09:01:16 pm
Ipe and a lot of the Brazilian hardwoods don't take to any kinda bending.
Title: Re: Bendy handle bbi dimensions, also kerfing
Post by: Prarie Bowyer on November 01, 2014, 09:33:15 pm
No heat at all.  Well a hot light for the glue.  The curves stay in great!  No splintering.  Only way to get it in ipe with out gluing on a separate piece.