What Seals in Rust?
Rust forms on all types of metals and on all objects, from metal fences to car parts. In some cases, painting over rust or sealing rust in is preferable to removing it with a grinder or sand blaster. On thin metal sheets and in hard-to-reach areas, this is especially true. If you are planning to seal in rust, several products will help accomplish the job.
Metal Rust Sealers
Rust sealers work to cure and lock in the rust, neutralizing the corrosive effects that pit and further damage the metal. Some rust sealers cover all the pores in the rust and permanently block out water vapor. They also neutralize acids and alkalis. Rust sealer is also a single compound, which means no mixing is required. Other rust sealers come in two parts requiring an accurate mix to create the final product.
Many paints seal in rust by covering the rust with a layer of paint. The paint acts like a layer of skin and protects against moisture infiltration. The effectiveness of the seal depends on the application of the paint and on its own characteristics. The stronger the paint is, the more effective it is as a rust sealer. Other factors influence the effectiveness of the paint as a sealer. For instance, Some rust primers make a paint primer that is applied over rust. Since it is a primer, a top coat is applied over it. The combination of primer and paint is more effective than a single layer of primer or paint alone.
Commercial grade masonry sealers are used on concrete walls and other masonry installations. These sealers protect the concrete and the iron rebar inside from moisture infiltration, which prevents rust and corrosion extending the life of the structure. The sealer is applied to the masonry and blocks all water and oxygen supply to the inside of the structure to prevent the formation of rust.