The Definitive guide to Bamboo Weapons in Belegarth by Tordek

Before we begin, understand, every bamboo weapon will eventually fail, and when it does, you will not be able to salvage anything from it, other than possibly the cover. When it’s done, throw it in the trash and build a new one.

Here is the big secret to core selection. Get Calcutta bamboo, no other bamboo type has been shown to hold up. Yellow/Chinese can be used for a spear, but is much more fragile than Calcutta.

Other points to consider for core selection are:
Wall thickness
Amount of core taper
Straightness
Pre-existing splits
Weight
Diameter
As for care of the weapon, the leading cause of splits is rapid swings in temperature. Thus, weapons build on bamboo should not be left lying in the sun or hot cars.

For building the weapon, like fiberglass, lightly sand the core with 60 grit fiberglass, and build as normal.

I saw someone post a link on a FB group to a relatively cheap online retailer, but I don't remember the site or where I saw the link. Where do you find yours?

Franks Cane and Rush Supply

http://www.franksupply.com/bamboo/bamboo-poles.html