Putty on top (not too much or you will plug the over flow) and pipe dope on the thread like spcwaters mentioned before. -personally, I like to use Rectorseal 5 underneath-
Gargalaxy, just curious.
What draws you to rectorseal 5? I have a tube I keep in my bag I use for black pipe, I'm not sure why lmao.
I usually use blue monster on everything else, I prefer the white rectorseal, but the supply house doesn't carry it and we got a guy that wears out the Home Depot card so I don't buy anything from there if I can help it.
I just find that stuff to be too messy and sticky.