Best wood for bamboo

[colin1991]

As long as you prep your bamboo properly, use a nice large diameter pole and thin it correctly before you glue it on you can get away with pretty much anything as a belly...  Timber choice depends more on weight you're after from the bow.

I've made 40lb bows with bamboo backs and red oak bellies... 50-70lbs I use Grey Ironbark or Spotted gum or Massaranduba (pacific jarrah) and anything over 70 I use Red Ironbark or Ipe...  You wont find spotted gum or the ironbarks in the states, they're Aussie natives but Osage would be a great substitute.

[alwayslookin]

Thanks for all the help gents. I think I will try Osage first and then locate some ipe.

[Springbuck]

When it comes to ipe is edge grained preferred over face grained?

It never mattered to me. I just want straight grain with no pins or swirls. They tend to give up the ghost on ipe.

Yeah, the growth ring orientation isn't nearly as important as having the grain run mostly straight end to end.  A little run off or some gentle zig-zags are ok, but kinks, angles, jogs, swirls, knots, and abrupt run-off are trouble.

[loon]

I'd like to see more bamboo-only bows. Bhutanese style bows seem pretty easy to make.

And I'd definitely like to know how the Song Mu Gung bamboo-only Korean bows are built - apparently a 51" ntn bow of bamboo can be drawn to 33"??! With reflex! Not sure if sinew backed or what...

Kind of off topic, but should one ever even bother trying to steam or boil bamboo to try to flatten it?

[Springbuck]

  Bhutanese bows require a special specie of bamboo that tolerates the inside of the bamboo being shaved down and still becoming the back of the bow.

  I also like the look and coolness of all bamboo bows, but they take a lot of understanding and forethought.  Large diameter bamboo helps.  I have had success just laminating two pieces of even thickness together front to front, and shaping it like a pyramid bow, then messing with the side tiller (because the lenticular cross section doesn't allow a perfect pyramid bow.) The technical issue is that you need to thicken the handle with a tapered middle handle block/lam, and that is not easy to do well with basic tools.  Also, you can scrape bamboo a little on the belly, and knock down the nodes on the belly, but don't do it on the back. 

  You CAN flatten bamboo side to side, and I have heard all kinds of guys do things like steam it between two boards that are clamped together tighter and tighter in increments.  Stuff like that seems like so much trouble. Go too fast and it splits, etc    I did learn that if I flattened the inside of bamboo and knocked out the inner nodes a bit, then ran the heatgun or torch over the outside of the bamboo, it would flatten itself.  Not completely, but a lot, then you can sand the belly again.  This tempered bamboo should only be used on the belly, though, because heat improves bamboo in compression, but NOT in tension as I understand.  Unfortunately, I have been to busy since I learned this to try it in a bow.

And the last thing I learned that I filed away is that there are a TON of bamboo varieties throughout the world.  So many.  There are huge 10" plus diameter guadua bamboo pillars used as construction timbers in South America.  There are tropical bamboos from SE Asia and India that are so dense they are solid all the way through and have a
band of the densest fibers 3/8" thick all around a 2" across pole.  They are so dense and hard it is scary.  Tre Gai bamboo grows 3" across and has only a 3/4" hole down the middle.  I always wanted to buy a pole, split it and make an all bamboo ELB.  But, most of this stuff is hard to get or super expensive to ship (can you imagine the shipping on a 12 foot long 10 inch dia. bamboo timber?) and I don't have any free time anymore.

 I also want to mess with cable-backed, bamboo belly bows more.

[loon]

Seems like cable or sinew backed bamboo bows would have great potential. Thanks for the info

I found this from paleoplanet, it looks really cool. like a bhutanese bow with recurves and a cable backing

http://s178.photobucket.com/user/OrienM/media/bow002.jpg.html