Twisted Binding

Lately when I have been bending binding it sometimes twists (racks?) at the tight waist bend ruining the binding strip. I have not had much problem with this in the past and only seen it before with some rosewood. Does this happen to anybody else? I have two theories: 1 It is me and I'm overcooking my binding while bending or 2, it is a grain issue and the strips were cut on a bias. I buy my binding from the same seller as before and they are reputable. Attached is a picture of some cocobolo binding with the twist. Picture does not show it well and it is worse than appears. Any ideas?

I was having similar issues with some really unusual koa bindings and cobbled together a process that worked really well for me, maybe it can help you. I divided it into two steps- rough bending, and "setting" the bend in a form. I taped four lightly wet bindings together tightly, then wrapped them in a few layers of foil. I bent these free hand roughly to shape, using a steel rule as a backing plate.

I made a bending form out of 35mm ply. The inside profile is cut just the same as you would cut a normal bending form for a heat blanket style bender. The outside profile is cut to the same profile, minus the width of the binding. This outside profile was cut into three sections- upper bout, waist, and lower bout. I take the binding packet right from the bending iron and lay it against the inner form. I use a heat gun and some hand clamps to slowly bring the two parts of the form together and leave them clamped tightly until everything cools.

I'm sure there are better ways to do this, but I was able to bend some pretty gnarly wood with grain all over the place.

Josh

It's more of a grain issue. I bend over a hot pipe and the odd piece of binding sometimes has an alarming twist to it. Of course bending on a hot pipe allows you to counter the twist but even that won't work when you come across a bad example. It's not unlike bending certain sets of sides, some will buckle like crazy even though you are bending dry and using a backing strip.

Thanks all. I think this is an issue of wood gonna do what wood wanna do and this wood wanna twist. What a waste of good wood.