After I cut the bamboo into 6' lengths I knock the internal nodes out with a hoe handle and let the bamboo dry until it turns tan. Letting it dry whole eliminates cupping and warping as it dries, with the nodes out you get a chimney effect and keep air moving through the trunk. if you don't knock out the nodes it will take months for the trunk to dry out, moisture will have to go out through the rind which is a very slow process.
After it turns tan I pop a chalk line on the trunk and run it through my bandsaw to reduce it to 2" wide slats. I use the bandsaw to remove as much of the belly as I can from each slat then give the slats a few passes through my jointer to reduce the belly to completely flat.
At this point I store it for future use.
