Black ABS can be repaired with PlastiMend. Need to lightly sand the surface to clean/prepare and the sealant/solvent melts into and combines with the existing ABS same as joining waste pipes. For large issues or to provide support with a flex point that broke you may need to add some sheet ABS to strengthen the area. I have used PlastiMend on a corner flex point that was a bit thin and ripped from the fill/empty/fill cycle. Has held over five years. This after using several other 'solutions'.
http://www.plasti-mend.com/They also sell on amazon
