How to remove or clean roofing bull?
 

I am trying to clean off some black tar like material the roofer put around the drain, he put a lot of it and then threw granules on top, making it impossible to completely close the flashing collar over the drain.

This material has somewhat cured and is very difficult to remove. I am using a knife but not having a lot of luck. Is there some special solvent or method to clean it up good?

Any petroleum or laquer based solvent I would think.

Are you talking about a clamping ring? What's it off for?

It wasn't off.

It was a new install. The roofer smeared bull all over the flashing that was folded over the drain opening, then threw granules over it, then the collar would not close because of the granules and will only screw in partially.

I have remove the collar and now am trying to clean off all the bull and granules over the lip just so the collar will close snuggly. This stuff is impossible to get off it's like trying to get peanut butter off bread.

I tried mineral spirit and not much luck.

Look for something with a bit more tooth like a Goof Off or similar.

Be sure to wear proper protection and treat with caution.

You aren't trying to get it spotless are you? scrape all the bulk of it off with a stiff putty knife/chisel and a hammer. It's messy as hell but it's not intended to come off.