Partial caul will do. It gives the wood support so it spreads the stress out instead of looking for the weekest point. It also gives it a shape to conform to. I wet the wood ,heat until it evaps, re-wet only four or five times . That should give you enough heat to bend . The wood will dictate that. Yes , round over the edges of anything you want to bend. The wood will change colour ,just not as quick as Maple for example. Try for just starting to change . If the wood splinters ,it's because it was too dry,too thick ,grain run off, too tight radius,bent too quick or not hot enough. Or any combination of the above and likely a couple I missed. It's the same as tillering. If you have a grain violation or uneven thickness, the stress will all be concentrated on the weekest spot. Remember , the longer you heat it the dryer it gets. Like a concentrated kiln. If you hold the heat gun on it long enough ,it will catch fire. As you can see from the pic, I have a mark on the caul that I use as a reference point to get the same bend. The caul is a gradually tightening curve so I can use it for all different bends depending on where I clamp and where I bend to. I measure from the tip and line it up on that pencil mark,say 8" I then make my bend and measure from the tip to the edge of the caul. When I do the other tip I just repeat the process to match it up.!5 minutes give or take for each tip. let it cool for a couple of hours on the caul. Wait untill the next day to work with it again.
