I'm finishing up a frame, and I am curious as to what I need to do sending it to paint.

I understand that most of the outside could be sanded or blasted, but what do you do on the inside, or are these things that the painters do? I have access to a blasting cabinet at work, but I can look inside the tubes and see a lot rust. Is this okay to leave that way?

What are your guys recommendations?

Also do you have any recommendations for painters in the Portland, OR area I could work with?