Tuesday, November 19, 2013

Repaint A Rusted Surface

Bringing rusty wrought iron furniture back to life is a rewarding endeavor.

Corrosive rust occurs when oxygen combines with iron or an iron alloy such as steel, at the atomic level. It is a lengthy process that results in the formation of a new compound called "iron oxide" which weakens the structure of the metal. Iron oxide forms when the metal is exposed to water or humidity. If this oxide, or rust, is not completely removed from the metal surface before repainting, it will spread under the surface of the new paint and cause it to flake off.


1. Prepare the work area. Scraping and sanding old paint from a rusted metal surface is a messy job that involves toxic dust, chemicals and sharp pieces of paint and metal that can be dangerous to eyes and small children. Find a well ventilated but non-breezy area and protect the ground or floor with a tarp. Gather all the materials you will need and don't forget to put on your goggles and dust mask. Since you are working with rust, avoid starting this process on a rainy or extremely humid day.

2. Clean the surface of all loose and flaking rust and paint. Surface preparation eliminates surface contamination that can also include dust, moisture or dampness, oil and grease that will interfere with the bonding of the paint to the surface. Scraping loose paint often reveals areas of rust that are not immediately visible.

3. Remove rusted areas. To clean moderately rusted steel, scrape loose rust scale off the metal and then use a wire brush or steel wool for a more thorough cleaning. Use a drill equipped with a wire brush to remove chipped paint and rust from ornamental iron work or wrought iron patio furniture. If the surface is extensively or deeply rusted, consider having it sandblasted. After you've sanded off the rust and smoothed the surface, wipe it with a rag dipped in paint remover to remove any dust. Always wear a dust mask, safety goggles and gloves for protection.

4. Apply corrosion-resistant primer. Make sure the primer and top coat are compatible by checking with your paint dealer. After removing old paint and rust dust, brush or spray on the primer. If you use a spray, it's very important to work the primer into the metal surface with a brush while it's still wet. Spray painting won't get the paint down into tiny crevices or pinholes in the metal, and this can result in the occurrence of more rust as moisture and oxygen attack the exposed surface. Notice the drying time for the primer and re-coat as soon as possible to help the topcoat bond with the surface.

5. Apply a topcoat of paint with a spray, brush, or roller. Spray paint is fast and effective, but it is more expensive than other methods. Rolling is also a fast way to apply the paint but whether you spray or roll, remember to back-brush to level the paint, fill in tiny spaces and remove drips.

Tags: metal surface, dust mask, paint rust, wire brush, wrought iron