Rust spot

[akrateffil]

All,
I am in the process of prepping a car to paint, it is a low budget old VW bug. It has many spots coming through the current paint. Have taken a DA and smoothed them down to metal but the rust mark never seems to go completely away. Though the project is low budget I still want the paint to last as long as it can. How should I prep these spots to keep them from coming back. I posted a couple pics showing a rust spot before DA, and another after using DA. What should I do to prep for paint?
Thanks,
Andy

 

[CFD244]

Anytime I run into that, I use a neutralizer like Naval Jelly and and scrub it with a stainless wire brush. There's also a spot blaster that I have but it's messy.

 

[rklein383]

I have used this product of a couple of my Mopars and it works great.
Rust Mort™ | morttm | SEM Products

 

[akrateffil]

Anytime I run into that, I use a neutralizer like Naval Jelly and and scrub it with a stainless wire brush. There's also a spot blaster that I have but it's messy.

.
Naval jelly doesn’t cause issues to paint over it?

 

[akrateffil]

I have used this product of a couple of my Mopars and it works great.
Rust Mort™ | morttm | SEM Products

do you have to keep the areas wet for a time using Rust Mort? What is ballpark cost for a gallon?

 

[MoparMike1974]

Any rust neutralizer with phosphoric acid will neutralize the rust. I like to work it in with a 3M pad. Wipe off the excess with a dry rag. Most will recommend rinsing with water but follow the directions for whatever product you choose. I like Ospho, been using it for years. Lastly, a good base of epoxy primer on the bare steel should take care of it.

 

[Murray]

POR-15.

 

[rklein383]

do you have to keep the areas wet for a time using Rust Mort? What is ballpark cost for a gallon?

like previously said, any phosphoric acid solution will work. This stuff goes on very thin and a gallon will do an entire rusty car, almost. I have used this product as well, https://www.homedepot.com/p/Krud-Ku...d7790767468512f876a0663cd29da5d4&gclsrc=3p.ds
It is around 8 bucks for 16 oz.

No, don't have to keep wet. Brush on, let is sit overnight or so and then wipe down area with water and a rag a couple of times. Let dry, ready to paint over.

 

[Max1196]

Rust Converter Recommendations. Aerosol for sun faded/surface rust car. | For A Bodies Only Mopar Forum

 

[CFD244]

.
Naval jelly doesn’t cause issues to paint over it?

I rinse it with water, so far no problems with the 2k epoxy sticking.