Visually it’s obvious that there is a difference between brushed satin and mirror-polished finishes of stainless steel. Brushed satin stainless steel has a soft sheen and looks like a ‘matt’ finish when put alongside a polished mirror finish. In contrast, mirror-polished stainless steel is a bright, highly-polished finish. In this article, we’ll answer the question, what is the difference between brushed satin and polished mirror finishes?
A brushed satin finish stainless steel is achieved by mechanically creating a directional grain on the surface. This process involves using a grit abrasive material to brush the surface in a specific direction. The result is a subtle, matte finish with a soft sheen that does not reflect light directly.
In contrast, mirror-polished finish stainless steel is achieved through a polishing process that creates a highly reflective, mirror-like surface. This process involves buffing the surface with progressively finer grit abrasive materials until the surface is entirely smooth and reflective. This finish reflects light directly, giving it a brilliant shine.
There are tiny grooves on the surface of brushed satin stainless steel. They aren’t visible to the naked eye, but trust us on this 😊 If you look at brushed satin stainless steel through a magnifying glass or under a microscope, the surface looks very different. One obvious way to tell if something is a brushed satin finish is if you can see which way the grain goes. A mirror-polished finish doesn’t have a grain and is so much shinier because these tiny grooves have been completely polished out.
Which finish is best for my project?
For some, the choice between mirror-polished and brushed satin is purely cosmetic. We would always recommend a mirror-polished finish if your project is in a coastal or harsh environment (think swim spas or pools). However, for indoor projects or outdoor projects that aren’t coastal, the choice is yours. Mirror-polished stainless steel withstands the elements much better than brushed satin due to its significantly lower surface area. This finish is sometimes referred to as super marine mirror polished, and impurities in the air struggle to stick to the shiny surface of the steel, as it doesn’t have tiny grooves to trap the salts and impurities. 316-grade stainless steel must be used in outdoor projects, but this is especially true for projects in coastal/harsh environments. 316g has a higher level of chromium and is much better at resisting the elements than 304g.
Brushed satin is more susceptible to ‘tea-staining’, which is the brown rust-like staining on the surface of the steel. This isn’t rust, as it is only surface discolouration and doesn’t affect the structural integrity of the steel. Even outdoors, provided your project isn’t coastal, a brushed satin finish will look lovely for years with regular maintenance.
As well as the environment the balustrade is in, stainless steel is also susceptible to contamination from other metals. It’s good practice to have a set of drill bits/taps/blades that are only used on stainless steel to avoid cross-contamination. Contamination of mild steel occurs just by contact, so we have a dedicated workshop for stainless steel fabrication. Even the dust and dirt from the installation can settle on the surface of the steel and cause tea-staining if left. It’s essential to thoroughly wash the balustrade down with hot soapy water after installation, to remove residual dust or swarf. This first clean goes a long way to ensuring the balustrade looks perfect for years to come.
How do I maintain my balustrade?
Both brushed satin and mirror polish need regular maintenance, but the cleaning methods are different. Mirror polish is very shiny and does show up marks and fingerprints very quickly, but these are easy to buff off with a soft cloth. For deeper marks, a metal polish such as Peeks Polish will usually do the trick. If your balustrade has intense scratches, these must be mechanically polished.
The directional grain created during the brushing process helps to hide minor scratches and scuffs that may occur over time with brushed satin. Removing these from brushed satin is also much more straightforward than from a mirror-polished finish. You can use scotchbrite pads to polish the steel to remove the scratches by hand. The key is to start with the least abrasive method (think buffing cleaner into the surface first) and work your way up from there. Start with the finest grade of scotchbrite and be careful whilst polishing, as you don’t want to create new scratches or unintentionally mar the finish. When removing scratches from brushed satin, it’s essential to pay attention to the orientation of the grain, as all your polishing and cleaning needs to follow this direction. Never work across the grain in the metal when trying to remove a scratch, as this is likely to cause more scratches!
Is mirror-polished finish more expensive?
Mirror polished balustrades are generally more expensive than brushed satin, and this is mainly due to the extra processing that is involved. As a general rule of thumb, a mirror-polished balustrade will be 20-25% more expensive than a brushed satin one. However, this is just a rough guide, and some designs are more labour-intensive than others, causing a more considerable uplift in price.
Do you have questions about the different finishes of stainless steel and which is best for your project? Give us a call! We’d love to have a chat with you regarding your project.
