I just wanted to share my experience with this product. It was given to me by a friend and I have to say it is the most incredible product I have ever used when dealing with rust. You paint it on right over rust and it chemically reacts to convert it into a paintable surface. You dont have to paint over it if you dont want. 1 gallon could do your entire truck. It looks like milk and you paint it on. It turns bluish greenish color and after about 30 to 60 minutes it turns the rust into a darker color and ends up looking more like you clearcoated the rust into a dark look. You can rub the surface after it dries and no residue no flaking of the rust, it is gone! Stops the rusting process dead in its tracks. I dont know how readily available it is but if you can find it you will not be disappointed. You can see it on applied in some of my pics from my google photos folder I shared.
Just google it
I can attach a link but not sure if we are allowed