Rust and Rust Removal
The key to a long-lasting paint job is proper surface prep and choosing the right product. But if rust rears its ugly head — as a nail head bleeding through, a surface stain from a can, or a blemish on wrought iron — here are ways to solve the problem.
on Painted Surfaces
by Stacey Enesey Klemenc
long-lasting paint job is proper surface preparation and the right choice of products. And nearly every structure, residential or commercial, is going to have some metal issues to contend with, ranging from rusty nail heads to peeling chunks of weathered wrought iron.
Rusting nail heads bleeding through paint
If rusting nails are showing through paint now, they'll do it again unless you take steps to prevent that from happening. The experts at the Flood Co. recommend sanding the heads and sinking them below the surface of the wood. Next, seal the heads with a primer-sealer or a primer that contains rust inhibitors. For the finishing touch, fill in the dent with putty to create a smooth, continuous surface. Now you're ready to apply a fresh coat of paint.
There is a variety of products on the market made to solve rust and corrosion-control problems. In 1988, Charles Grigsby created Zero Rust, a product he maintains "contains rust, period." First scrub the nail heads with Zero Rust Prep Step, a powder that mixes with water, to get off the grit. Let the nails dry, spot them with Zero Rust, and "then you can paint the surface anything you want." The product works better with pigment, he says, but a top coating is completely optional.
Rust-Oleum's Rusty Metal Primer is available as a spray, in quart containers or in a convenient bottle with a built-in brush attached to the cap. "For nail heads, the bottle is ideal," says Jan Healy, senior brand manager for Rust-Oleum aerosol products.
Barry Dubin, vice president of Dumond Chemicals, says instead of a rust inhibitor, shellac will also stop the rust from going through the paint.
To clean up the rust stains but not to stop the rust, an environmentally friendly Canadian product could come in handy. Simple Wash, from Napier Environmental Technologies Inc., cleans and brightens any outdoor surface, including wood decks, plastic decks and treatments, vinyl siding and gutters, stucco, concrete and fiberglass. It will readily remove rust stains and rinses easily with water.
The company's technologies are specifically developed to replace unsafe harsh chemicals and unacceptable mechanical methods still common in the industry.
Rust stains from a can on surface
To remove a rust stain, a product with some type of acid is usually necessary. However, you may be able to remove a rust stain with good old-fashioned soap and water.
Simple Wash also can be used to remove rust stains on all coatings and treated lumber at recommended-use dilutions. Depending on the surface, a gallon will cover anywhere from 200 to 2,000 square feet. Scrubbing may be necessary to remove heavy rust stains. Allow it to set five to 15 minutes before rinsing.
On natural and manmade stone surfaces, Safe n' Easy Masonry Rust Remover from Dumond Chemicals will remove a variety of contaminants, including rust. The slightly acidic, heavy-duty cleaner is ready to use. Simply apply to the affected area, let it set for 15-20 minutes and hose it off. For best results, pressure wash.
Rust-Oleum Rust Stripper will take rust stains off a metal surface but, cautions Healy, "It's powerful stuff and it can take the paint right off. Don't use this product on nicely finished surfaces."
Rust on wrought-iron railings
Before applying any coating to a metal surface, be sure to remove any loose rust. For small jobs, a chisel-style scraper and hand-held wire brush will usually do the trick. Larger jobs may require power wire-brushing or disk-sanding with aluminum oxide paper. Experts from the Rohm and Haas Paint Quality Institute contend that it's not necessary to remove every bit of rust, but rather to remove as much rust as these methods allow. Next, rinse the surface to get rid of the rust particles and dust for better coating adhesion.
There are several products designed to make this type of rust removal easier. Safe n' Easy Metal Restorer from Dumond Chemicals is a concentrated product designed to quickly remove rust and other contaminates from copper, brass, bronze, stainless steel, aluminum and glass surfaces. An added inhibitor prevents rust and oxidation from reforming. "This will shine up the surface beautifully and you don't have to paint it," says Dubin.
Zero Rust — a high-solid, low-VOC, impermeable, direct-to-metal barrier coating used by the Marines and U.S. Navy — is formulated for complete rust and corrosion control. It can be applied over fully or marginally prepared surfaces.
You also can use Rust-Oleum Rusty Metal Primer to drive out moisture and to prevent that area from rusting in the future. "Only apply the primer to areas that are rusty," Healy says, "and then repaint the wrought iron with Rust-Oleum Protective Enamel, which comes in different finishes and hundreds of colors."
RemovAll 400 rust remover is an excellent choice for railings, says Brian Morse, vice president of research and development for Napier. No prewashing is necessary. Simply apply the thick gel to the railing and let it set for 15 minutes. If you're going to apply a coating, wipe off the product with a cloth and rinse the railing with water. If you're not going to recoat the railing, do not rinse off the residue.
If you're looking for a paint primer and rust converter all rolled into one, check out the solvent-based Rust Destroyer or the waterborne Rust Knock Out from Advanced Protective Products Inc. Both products, which are guaranteed for five years, can be applied directly over rust with no scraping, sandblasting or washing before or after applying. The nontoxic products meet the EPA's Rule 66 guidelines on solvent emissions. The products, which are only available in red, can be used under and over all finishes.