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Dealing with rust damage

Bicycles, barbecues, patio furniture, lawn and garden equipment, steel window frames, rain gutters and downspouts are some of the things around the home that are susceptible to rust damage.

Aside from its ugly appearance, left untreated, rust can bring any of the aforementioned products to an early demise and lead to other damage. For example, a leaking rain gutter due to a rusted joint can allow water to travel along the wood trim at the roofline or down the wood siding. This will result in rot that might cost hundreds or even thousands of dollars to repair.

Another example is a rusted window frame. Water could enter through the frame and go down into the wall framing below. This might require the removal of the wall and the need to replace it with new framing, siding and plaster or wallboard.

Rust presents a safety issue as well. A rusted-out screw or the rust-ravaged leg of a garden chair could result in a nasty fall. Rusty outdoor power equipment leaves the operator particularly vulnerable because a damaged bolt can become a projectile.

Dealing with rust is usually a paint project, and when it comes to painting, preparation is important. First, rusted screws and fasteners should be removed. Install replacements after surrounding rust has been eliminated and the object has been refinished. A couple of the most difficult aspects of replacing a damaged fastener are removing it and locating a replacement. One of the best methods of removing a rusted-out piece is to saturate it with a penetrating lubricant. The lubricant is usually just what's needed to break the bond in combination with a screwdriver, pliers or wrench.

The next step is to remove as much rust as possible. A wire brush will remove the majority of the surface rust. However, if you're anything like us, you'll likely take the path of least resistance and use a wire wheel on the end of a power drill. For safety's sake don't forget protective goggles, gloves, long sleeves and a mask.

The remaining rust can be handled in a couple of ways: chemical removal and chemical conversion. Phosphoric acid-based rust solvents work well in removing rust from all kinds of surfaces.

Rust converters can be used when it is impossible to remove rust down to bare metal. The rust converter is a coating that chemically converts the rust to an inert paintable surface. It contains ingredients that will inhibit future rust growth.

Whether or not a converter is used, the next step is to wash the metal to improve primer adhesion. There are various one-step washing products available on the market. Most of these primers contain one form or another of acid: phosphoric, acetic or citric acid. We have found that straight vinegar on a soft cloth works quite well. Once washed and allowed to dry, the metal should be painted with a primer designed specifically to be used with metal. Metal primers contain ingredients such as zinc oxide and red oxide which help resist rust. Additionally, a primer provides extra resistance to harsh elements and improves adhesion of the topcoat. We prefer an oil-base metal primer -- even if a rust converter has been applied.

Most exterior metal surfaces will be more abrasion-resistant and last longer if an oil-base enamel top coat is applied. In fact, some of the rust converters require an oil-base top coat. Metal railings, garden furniture, toys, outdoor power equipment and farm equipment should have an oil-base top coat because of the abuse to which they are subjected.

Exceptions to the oil-base top coat rule might be gutters and downspouts, for one primary reason: architectural appearance. An acrylic latex top coat produces a low sheen that tends not to draw unwanted attention to these architectural elements. If they are to stand out, it should be a function of color and not paint luster. Further, due to their inaccessibility, abrasion resistance provided by oil-base enamel isn't a priority.

Grills, fireplaces, wood or coal stoves, heaters and furnaces should be top-coated with high heat enamel specifically designed for use with items that are too hot to touch. They generate heat in excess of 200 degrees F.

Converters, primers and paints can be sprayed, rolled or brushed. When spraying, it's always a good idea to back brush for a smooth, uniform finish. Remember to use a natural china bristle brush when using oil-base paints. Synthetic brushes made from nylon or polyester work best with latex paints.

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