connecting ABS p-trap to brass bathtub drain and overflow kit

Hi,



I am installing a new bathtub in my home and I will be connecting it to a new drain leading to the main stack. For the tub I have used a brass bathtub drain and overflow kit and I am now trying to connect the brass outflow to an ABS p-trap. I am using an ABS slip joint 1 and 1/2 inch on one side and 1 and 1/4 inch on the brass side but it really does not seem like a very good connection. The plastic washer is in place and I hand screw it tight but I can still slide it off with a little force.



Is there something else that might work better?



Do people sometimes use some sort of goop to help seal the fitting and hold it in place or is the washer really all that is needed.



Thanks



Bindy

connecting ABS p-trap to brass bathtub drain and overflow kit