i am installing crown moulding in a bedroom. 13 x 13 . i plan to cope the inside corners. i plan to put coped end to but cut, coped end to but cut and so on so that i will not have to cope a 13 foot length on both ends. turns out this seens to be imposible . how do i deal with having to cut two miters on on length. i was told this would be imposible to get the right fit.