I have a fire place insert . We Bought the home and it was 10 years old I can't find any material on it. But the back of it has been nearly knock out with logs in badly needed repair

Cora, most inserts are dual walls to accommodate a blower, are you sure the damage happened by the firewood? If the undamaged metal is in good enough shape you can replate, if your not a welder then see a local welding shop for the repair. Good luck