We get email questions that can also benefit our other readers. Here is an email from a Maryland reader. This customer is working to get rid of rust on his SUV and has some specific questions regarding rusty metal we would like to share with you. This reader included his own pictures for illustration. We love to get pictures from our readers. If you have any before and after pictures of your projects, send them our way. We can feature your rusty metal projects in a future blog.
1. Is Rust Doctor thin enough to be sprayed using a garden sprayer, such as the one below? If not, can it be thinned with water and retain its effectiveness if used in multiple coats? I’d like to use this wand to get down between inner and outer fender panels and other hard to reach places on my SUV.
Rust Doctor is thin enough to go through a garden sprayer. However, the pressure in the sprayer is not enough to atomize the paint to give you a nice even spray. For the use you describe, this process will work fine as the sprayer will get the Rust Doctor to the surfaces you want to treat, just not in a nice even spray. You do not want to thin Rust Doctor as it will diminish the effectiveness of the product. The viscosity of Rust Doctor is more fluid than Latex paint which allows you to use it in a spray gun with a latex tip. Also, it is fluid enough to penetrate seams and crevices to convert rust to magnetite and completely seal them. This makes reaching those rusty spots easy for the restorer. That way you don’t have to take door panels etc. apart. Regarding multiple coats, usually only one coat of Rust Doctor is needed to treat a surface. Heavy rust may require a second coat. Apply the second coat of Rust Doctor while the first coat is still tacky.
2. What is the “pot life” of Rust Doctor once a container has been opened?
You can open and close a container of Rust Doctor as much as necessary without affecting the two year shelf life.
Make sure that Rust Doctor is not exposed to freezing weather.
3. Your site says Rust Doctor can be used over paint. If I treat the lower fender chips shown in the photo below, will it only affect the rust spots and leave the paint alone? In your video, it seemed to stain the paint, as well. My thought was to treat, fill the chips with filler, sand, and spray on a rubberized coating. Do you think that will work?
Rust Doctor does two things when you apply it to the surface of rusty metal or rusty metal and paint. The rust converters change the red iron oxide we call rust to a non-rusting black iron oxide called magnetite which will never rust. The magnetite actually protects the base metal from ever rusting. The entire surface that is treated is covered with a clear latex primer. So when you paint your lower fenders, the Rust Doctor will convert any rust on the surface to magnetite and coat the entire surface (paint and converted rust) with a latex primer. You can then top coat the surface with any kind of paint, bed liner coating or sound deadening material. Nothing in Rust Doctor will affect the paint. The stains you refer to is some of the rust in the clear primer picked up by the brush and converted black magnetite. This does not affect the surface in any way. Your suggestion of filling the chipped spots after Rust Doctor treatment with filler and then painting with a rubberized coating should work just fine. The latex primer in Rust Doctor will fill the nicks to some degree, requiring less filler. By the way, when you paint Rust Doctor on the fender you will see a lot more black spots on the surface than rust spots on the surface before treatment. That is because Rust Doctor finds any rust on the surface and coverts it to magnetite, even the tinniest little scratch or nick in the paint.
REMEMBER: Rust Doctor is non-toxic, non-flammable and biodegradable. All Rust Doctor products are made in the USA!