How to Powder Coat Coil Springs

No matter their purpose – be it appearance or corrosion resistance – sometimes plain metal springs simply aren’t enough. When this occurs, adding an interesting surface finish to enhance functionality or appearance without altering dimensions is the solution.

Two such processes include plating and powder coating. Here is what you should know about these processes:.

The Process

Coil springs play an integral part of a vehicle’s ride control system by helping absorb road impacts and support its weight, as well as stabilizing it on various terrain and road conditions.

Quality coil springs are constructed of wound metal coils that offer drivers a smooth, comfortable ride. However, some vehicles experience spring failure due to overloading – compressing coils over time until they break. When one breaks, suspension components such as struts and shocks may become damaged as a result of suspension component damage caused by broken coil springs.

To address these problems, many vehicle owners opt for having their coil springs powder coated. Powder coating uses an electric charge applied to powder particles as they are sprayed onto parts being coated and then cured at high temperatures – unlike chemical blackening or electrocoating which may alter dimensions over time. It’s therefore vital that only accredited facilities offer powder coating services.


Prepping springs for powder coating begins with an intensive cleaning that removes any dirt, grease or oils accumulated on them – this will enable the powder coating to adhere more securely and last longer.

Next step in powder coating the parts is sandblasting them. Sandblasting may reveal surface weaknesses on parts, for instance exposing a center bolt hole that allows shearing or spring breakage between U-bolts.

Metals like cast iron and aluminum contain pores that absorb oils during their manufacturing or usage processes, or during use. To eliminate this oil absorption, pre-baking at higher temperatures than powder coat curing is used (called outgassing) is required of cast parts as well as those exposed to an oily environment. This process helps eliminate these pores.

The Coating

Powder coating provides springs with a hard, stylish, and corrosion-protective surface finish that does not drip or run, providing seamless protection. Unlike liquid finishes, which often drip and run while providing protection, powder coating provides seamless protection.

Note that coating does not alter OE spring rate, wire diameter or coil count; adding additional coils could create touchpoints before full suspension compression which lead to coil binding causing immediate suspension component damage.

Powder coat cannot replace proper preparation of parts. Your local powder coater should sand blast your springs thoroughly to remove all dirt, oil and rust before powder coating them; this is necessary for creating long molecular chains which provide increased durability and resistance against environmental conditions, and remove imperfections to enhance aesthetic appeal – otherwise early failure of either coating or springs could occur.

The Finish

Powder coating on springs may chip under extreme stress, which is one reason Eibach recommends painting springs instead.

Powder coating springs is not only durable and visually appealing, it also adds an additional layer of protection by sealing them from dirt and debris that could scratch or dinge them over time. Powder coating makes a particularly attractive choice for springs that will be exposed to offroad use or experiencing lots of road wear.

I have personally had several coil springs powder coated and have seen no discernable change to their rate afterward, as the 400 degree temperature needed to cure the powder coat does not reach temperatures high enough to cause weakening that would eventually result in breaking.

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