My adaptor is an oval... about 5 and 1/2 by about 11 inches or so... just placed on in each end. Unless the iron broke, you could lift the insert with it... linear expansion with heating... pushed the liner further in, when it cooled, it pulled it further out. With the angled approach, the binding between the adaptor and the insert walked the thing right out of the hole.
"Not good"...
"Not good"...