Faucet Corrosion Guide: How to Diagnose, Remove & Prevent Rust

The bathroom environment has high humidity. Water vapor, condensation, and splashes provide the electrolyte for oxidation to occur.12 Poor ventilation can trap moisture, allowing water to sit on the faucet’s surface.

“Hard water” contains a high concentration of dissolved minerals like calcium and iron. When this water evaporates, it leaves behind mineral deposits known as limescale.

These deposits can trap moisture against the surface, creating areas where corrosion can begin.

Many common household cleaners contain chemicals that can be destructive to metal finishes. Abrasive powders can create micro-scratches.

Cleaners containing bleach or ammonia can be particularly damaging. Ammonia is known to be aggressive toward brass and can strip away protective plating.

Most faucets consist of a base metal, like brass or a zinc alloy, plated with a protective layer. Scratches, dents, or normal wear can create an opening in this plating.

Moisture can then seep underneath and cause the plating to bubble and peel away.

Less expensive faucets may use lower-quality zinc alloys or thinner plating. These materials are often less resistant to corrosion.

This form of corrosion occurs when two different types of metal are in contact with each other in the presence of water, creating a small electrochemical reaction. One metal, the anode, corrodes at an accelerated rate.

This can happen when steel washers are used with a brass faucet or when new copper pipes are connected directly to old galvanized steel pipes.

This reaction can cause parts to fuse, making future repairs difficult.

A constantly dripping faucet provides a persistent source of moisture, which can speed up both oxidation and the formation of hard water deposits.

Baking soda is a mild abrasive. A paste can be made by mixing it with water. Adding a few drops of white vinegar can create a fizzing reaction that helps dissolve rust particles.

Apply the paste, let it sit for 10-15 minutes, and then gently scrub with a soft cloth.

The citric acid in lemon juice can help break down rust. Sprinkle salt over the rusty area, then squeeze lemon juice on top. Let it sit for several hours before gently scrubbing.

This technique uses a chemical reaction and mechanical action. Crumple a piece of aluminum foil, dip it in water or white vinegar, and gently rub it over the rust spots.

Aluminum is a softer metal than chrome plating, so it can polish away rust without typically scratching the finish.

Products like CLR and Evapo-Rust are formulated to dissolve heavy mineral deposits and rust stains.1 It is important to follow the manufacturer’s directions, wear protective gear, and ensure good ventilation. Always test the product on a small, hidden area first.

Tools like a pumice stone or fine-grade steel wool should be used as a last resort. A wet pumice stone can be used on porcelain sinks but may scratch most metal faucet finishes.

Chemical cleaners should not be left in contact with fixtures for longer than the recommended time, as this could cause damage to the finish. For example, CLR suggests a contact time of no more than two minutes.

If rust has created deep pits, the finish is peeling in large sections, or the faucet has persistent leaks, the fixture may be nearing the end of its functional life.

Many faucets have a functional lifespan of 15 to 20 years. Beyond this age, finding replacement parts can be difficult.

If a faucet requires constant repairs, the cumulative cost and time may suggest that a replacement is a more practical choice.

If the “Water Test” revealed a corroding water heater or aging pipes, replacing the faucet alone will not solve the underlying problem.

Clean the faucet to look for a logo, which is often on the base of the spout, on the handle cap, or on the pop-up drain stopper.

Look for a tag on the water supply lines that may contain the manufacturer’s name and model number.

With the water supply turned off, the handle can be removed to inspect the internal cartridge. The cartridge often has a part number or a distinctive shape and color that can be used for online identification

The top of the faucet stem, called the broach, has a series of “splines” or teeth. Different manufacturers use a specific number of splines, which can help identify the brand through online guides.

Creating a waterproof barrier at the base of the faucet is important. The choice between plumber’s putty and silicone sealant depends on the countertop material, as using the wrong one can lead to staining.

Using plastic or nylon mounting nuts instead of metal ones can help prevent galvanic corrosion by electrically isolating the faucet’s metal components.

After installation, check all connections for drips. A leak can indicate a worn or improperly seated part, like a washer or O-ring, which should be addressed to prevent constant water exposure.

Wiping the faucet with a dry cloth after use can prevent water from sitting on the surface, which helps to stop both oxidation and mineral deposit formation.

Using a bathroom’s exhaust fan during and after showers helps to vent moist air outside. Opening a window can also be effective. In very humid environments, a dehumidifier can help control moisture levels.

When purchasing a faucet, consider materials known for their durability. Solid brass (especially with a chrome plating) and stainless steel are often recommended for their resistance to rust and corrosion.

An additional protective layer can offer defense against moisture.

• Quick Method: Applying a thin coat of automotive carnauba wax to the faucet every month or two can create a surface that causes water to bead up and roll off.
• Durable Method: For a more lasting solution, specialized clear coatings designed for metal, such as Nyalic, can be applied to seal and protect the surface.

For homes with hard water, a whole-house water softening system can remove minerals like calcium, magnesium, and dissolved iron through a process called ion exchange.

This addresses a common cause of limescale buildup and rust staining. For very high iron levels, a dedicated iron filter may also be useful.

Inside every tank-style water heater is a “sacrificial anode rod,” typically made of magnesium or aluminum.

This rod is designed to attract corrosive elements, corroding away to protect the steel tank. This rod should be inspected every one to three years and replaced when it is significantly depleted, which is often every three to five years.

Regular inspection is particularly relevant for homes with water softeners, as softened water can sometimes accelerate anode rod corrosion.

For routine cleaning, mild soap and warm water with a soft cloth are sufficient for most faucets and will help preserve the factory finish.