I'm 41 and I guess it's never to late to learn something so big as this. Thank goodness we are trying to learn and can hopefully break the cycle with our own kids. I appreciate your empathy and wise words, that means a lot.
Breaking the cycle is precisely what I want to do - exactly!
I spent a great deal of the day thinking about all of these posts and I'm sure they will help when I have to lay down the law with him.
(His daughter is in town visiting and I don't want to ruin their week. On the positive side, we haven't communicated much and I think it's been really good for all of us).
Just for what it's worth-- you telling him what you need (him not to be in your life right now) is never going to be at the "right time" and if for your serenity you want to tell him now, do it. You are not responsible for his reaction or how he chooses to spend time with his daughter after hearing what you have to say. And honestly, maybe saying it to him now while his daughter is around is a good idea. Maybe she is too afraid to say something to him (since I am guessing his addiction is not a secret) and having the issue addressed is something that needs to happen.
At the end of the day you get to choose when it is best for you to set boundaries for your life. Don't wait for the right time -- it'll never come. I waited 8 yrs to face reality and that was 8 yrs too long.