jsouth
Member
Stock screws (or screws modified to be rounded on the end) are vital. However, even with stock screws, on the screws that thread into the tank I find that it helps to avoid ANY misalignment of tupperware and threaded hole. I look at the alignment and press or pull on the tupperware with one hand until there is perfect alignment BEFORE inserting the screw, and hold it there until the screw is threaded in. If the tupperware is not aligned well (and it never is to start with) there are off-center pressures applied to the screw that will strip out or cross thread the threaded hole in the tank.