Slight leak on compression ferrule

[dmen]

Hi there, installing a PTrap on a new bath tub and going from galvanized to standard 1.5" PTrap.
The guy at Ace sold me a brass adapter that screws onto a threaded section and then accepts the PTrap pipe using a brass compression ferrule.
When I leak test I get a drop or two of water coming from the spot with the arrow.
Do I need to just tighten it more or? It's pretty tight already I think...

 

[johnjh2o]

Put some pipe dope on the ferrule. Also that wouldn't be my choice for a tub trap.

 

[dmen]

I read various you should's and you shouldn'ts about doping the ferrule. Not just tighter?

And why would that not be your choice? What would? I just bought a PTrap... It's pretty much like what I replaced too.

 

[dmen]

FYI - tried to edit my last post, didn't work...

Anyway, did a bit more reading - you would use PVC? The overflow that came with the tub is 1.5" brass... much like the trap in the pic so it seemed natural. I thought it odd to go from the brass to pvc then to galv.

Also - this trap is accessible.