Hallo people,
I am playing with shafts these days and I cut down some little trees to make harpoons with.
Yeah I know I should have done that between November and January, but that's not the point.
The point is, some of these trees are slightly curved, so I decided to hang them to the ceiling with a leather string, the heavier end down side.
This because I thought that gravity would work as a traction force, "forcing" the wood to unbend while it dries out.
I knew I could use heat as well, but would it work on green, thin wood?
What do you think about my method, and what's yours?
I looked for similar discussion, but haven't find any.
Greetings,
Mauro.

I have no experience yet but I watched an episode of weaponmasters about the atlatl where atlatl bob straightened a fallen branch from the DC area (so probably oak or a similar hardwood) it looked like it was kindling material, not green at all, and it straightened really well. So heat might  work fine even if it's not very green.

I've never been able to make hanging with a weight as straight as when I used heat, then again, I haven't tried hazel.   I have river cane, arrow cane( types of bamboo), and Chinese Privet Hedge, and Youpon Holly, and a few other native hardwoods for arrows and dart shafts.  Incedently, river cane make a great dart point and an OK fish spear when green but becomes too bouyant when it dries out.  A hardwood shaft makes a much better fish spear.

Cut your shoot extra long.  You can hand straighten a green shoot, don't de bark it and straighten it every three days or so, tie it in a bundle when you are done.  Depending on humidity and temperature, it will take a week to three weeks to dry and stay straight.  That means you will have to straighten it at a minimum of three times and probably ten or twelve.  Once it is dry, scrape the bark, cut to length, remembering to leave space for nocks on BOTH ends.  Then burnish it and rub in some type of oil or fat.  When you burnish, you can get your final straightening because you can curve your shaft into a hula hoop if you do it wrong.  Support the section you are burnishing on a flat surface.  Incedently, you save yourself a lot of work if you just cut a straight shaft to start with.

Remember to make haste, slowly.  Heat your dried wood slowly, get it hot all the way through before trying to bend it.  Once it gets hot, you have a very limited amount of time to bend the wood.  If it starts to get stiffer, stop and re heat.

To clear things up,my hung up weighted method just keeps the wood drying as it was,it doesn't let it curve additionally as it dries.So straightening before and after is needed for straight shafts.

Any heat source will do, coals, a low fire, a burner on a stove, a heat gun, a camp stove, those are all I can think of right off the top of my head.

heat box works also wet put in heat box 3 60 wat light bulbs work well

  When it comes to big shafts for spears or harpoons I don't do any straightening, I simply cut trees that are straight to begin with and then wrap them all up together really tight in a bundle of no less than 5 then either stand them up in a corner or lay them across a few beams in the top of my shed, but be sure that they aren't just supported at both ends or they will bow.  Bundling them up will keep them from going crooked as they dry, when you tie them up wrap one end around and around with the cord, then spiral it down the bundle to the other end and wrap that end up then spiral it back up to the original end and tie off, if you spiral it like that I find it keeps them straight better.
  For small shafts like arrow shafts I straighten them every day with bark removed if wood permits without checking just by bending them straight while they are green, when they dry they should mostly be all straight, then the ones that aren't I heat straighten. 
  If you are looking for good harpoon/spear shaft wood try spruce, fir, or cedar.  Go somewhere deep in the woods with a lot of tall shady trees around and find some saplings growing in a clump, trees growing in the shade grow straighter and taller for their diameter to reach the sunlight and have most of their branches on the top to absorb the sunlight, this is doubled if they are also growing in a clump, this way you get a tall straight tree with few or no branches for most of it.  Another great place to find them is alongside highways, (if you can do it legally,) as they have cut back very deep forest in some places and you will see a line of straight trees all along the roadside.