I have always used a product called Rust Seal to take care of rust that is too much of a pain to strip. See the pictures below for encouragement. Its pretty easy stuff to use, you brush it on, let it sit for about a half hour and repeat. Then hose off all the extra. It converts the rust to a primer like coating. This is must easier than stripping all the rust off those hard to get to areas. I have been frustrated to the point you are at, but its all worth it when its done. You will not even remember the frustration when its all done.
Rusty
After Treatment
The product
