Incest Survivors Support Group
Incest refers to any sexual activity between closely related persons that is illegal or socially taboo. Consensual adult incest is very rare. Incest between adults and prepubescent or adolescent children is a form of child sexual abuse that has been shown to be one of the most extreme forms of childhood trauma. If you or a loved one is a survivor of incest, join the group...
If your father could hold onto such a delusion, then there's every chance that nothing you say will get through to him. If you express your anger in person and once again he brushes it off, will you feel peace or will you feel more enraged and powerless? That's the worst worry - that your father will make you feel powerless all over again.
Therefore I feel you should write to him, not confront him in person. That way you get to have the last word, especially if you throw away any response you get without reading it.
I hear you about wanting to express your anger, I struggle with the same question about my mother (in my case, she's the reason I'm on this board).
You write that you don't expect anything from him but you need him to know your anger. The danger that I see there is that he will see your anger but it won't make him feel guilty, ashamed or anything. A lot of things could happen: He could throw it right back at you the way he did before, he could even be pleased to know that he has hurt you. I'm really sorry to say this, but I know that some of my abusers liked the fact that they had the power to make me suffer. The choice is yours, but be aware of those dangers, think about how it would make you feel if that happened and be sure you protect yourself. If you want to confront him in person, the best would probably be to not do it alone. If you want to write him a letter I second donnawanda's suggestion to throw away any responses without reading them.
Whatever you decide to do, I hope it will help you. Thoughts of healing and support to you.