Why Do Brass Door Handles Patinate So Quickly?

We’re often asked why some brass door knobs and lever handles patinate at a faster rate than others. First, let’s start by exploring what patination is and how it occurs.

What is patination?

Brass is an alloy formed of copper and zinc. Natural brass patination occurs as a result of a chemical reaction between the copper and zinc in the brass and the elements in the environment. Over time, the surface of the brass will react with air, water, and other environmental factors, causing a layer of copper salts to form on its surface. This layer of copper salts is what gives the brass its distinctive patina.

The specific colour and pattern of the patina will depend on the composition of the brass, the environment in which it is exposed, and the length of time it is exposed. Brass that is exposed to high humidity and saltwater may develop a green patina, while brass that is exposed to air pollution may develop a black or brown patina.

Brass will typically reach maximum patination after about two years, but the process of natural brass patination can also be accelerated or slowed down by various factors. For example, the use of protective coatings or the regular cleaning of the brass can slow down the patination process, whilst exposure to harsh chemicals or abrasive materials can speed it up.

Rates of patination

Let’s take a look at the reasons some door handles may patinate faster than others.

• The chosen finish of the handles will affect how quickly you see the results of patination. If you’ve selected a Dark Bronze Waxed, our darkest finish, you’ll notice the brass wearing back to its original colour faster, in comparison with a Mid Antique Brass Waxed finish. This is purely due to the large tone difference between the base brass colour and the applied finish.

• Exposure to the elements – if the handle is used on an external door, the brass will have greater exposure to moisture, which will speed up the oxidisation of the copper in the brass. The speed of this will increase in marine locations or areas where there is a high level of pollution.

• Amount of use – you’ll notice that handles that are used more frequently patinate faster. This is due to the oils transferred from your handles to the handle, which will react with the brass, speeding up patination.

View our blog on maintaining brass finishes here. If you have any questions on our finishes, reach out to our team at hello@josephgiles.com, or call +44 (0) 20 8680 2602.