I heat mine quite a bit longer before bending. I like to let the stock heat all the way through before trying to bend. Usually wait from 30 to 45 minutes. It's probably from making damascus - with 6 to 9 layers of steel at start if only the outside layers are at welding temp and it's beat togeather the billet looks good but the inner layers aren't welded. You end up with a pile of sh**. So I like the inner wood also hot enough to bend so all the stress of bending is applied through out the wrist area. Good luck to all - Paul