I'm installing a Vogelzang TR-004 wood-burning insert in my house with a standard 6" stainless flexible chimney liner (the kind with tiny ridges spiraling around the whole length). They'll be situated in my old fireplace. The liner comes into the fireplace rather vertically, and does not need ovalizing. However, the TR-004--like many inserts--has an exhaust collar pointed to the rear at roughly a 45-degree angle. Problem: the flexible liner is at a different angle, but is not flexible enough for me to hand-bend it (just near its end) to meet the insert's angle. Is it even possible to bend the flex liner, just near where it meets the insert? If so, what technique might I use to bend it? Or should I better look for an angled adapter? I searched Youtube to no avail about this problem.