I have my bottom drain going to a 4 inch pipe then a 4 inch 45 elbow then a 3 foot section of 4 inch pvc comming up out of ground i had to raise my cetus sieve because i raised the perimeter of the pond so i had to cut the pipe and glue on a collar to co ntinue running the pipework. When i cut the other end of the pipe i cant get it square so the pipe comming out of ground butts up all the way around inside the collar. Any one know how to cut this correctly?