Looks like I am getting the best results using the Phosphoric acid I bought at home depot. It's the same ingredient as in Naval Jelly but cheaper. I used a brush to put it on and Armor All Car Wash soap with water to clean it off. Here are some shots after a single application.
Now I need to use steel wool to agitate it and keep the surface wet using a squirt bottle,
The link below suggests I use steel wool to agitate it and keep the surface wet using a squirt bottle, rinse, lather, repeat, lol.
Check out this old hot rodders results:
secrets of surface rust removal revealed
