Carborundum Tactile Indicators
An extremely hard wearing, anti-slip Tactile Indicator solution...
Throughout our 25 years of operation in the tactile industry, we’ve tried and tested countless products to assess their viability for use in the public domain. Below is information about one of our discrete tactile indicators - there are pitfalls to avoid when choosing a suitable product.
Carborundum, also known as silicon-carbide, is a naturally occurring mineral – although it is quite rare so almost all the silicon carbide used for industry is manufactured. Manufactured Carborundum is formed by bonding silica grains together with carbon in an extremely hot furnace (a process called sintering). Carborundum is used all around the world for various applications such as automotive i.e. brakes and diesel particulate filters and abrasives for cutting and grinding discs. So where are we going with this? Well, Carborundum is also used as an infill in tactile indicators - like the product below.
Carborundum is used as it is exceptionally hard, giving great wear characteristics and when bonded together with epoxy resin, provides excellent anti-slip functionality. It’s also an aesthetically pleasing form of discrete tactile indicator that architects like to choose for their signature projects.
So, what about the photos below? Why do they look like they’ve got faded sand infills? Well, they are not filled with carborundum at all - when Carborundum is produced the natural colour is black/brown so almost impossible to tint to a lighter shade.
Instead, Tactile manufacturers take a fine white or translucent aggregate (not carborundum) and add a yellow colourant along with the epoxy to use as an infill material. Unfortunately, the UV stability and general quality of the colourant is, more often than not, poor; resulting in rapid fading when the Tactile Indicators are exposed to the sun. Poor infill mixtures can also result in the infill falling out - wrecking any of the originally intended asthetic appeal.
Once the tactile indicators fade to this extent, they are not only non-detectable to the visually-impaired but non-compliant and a potential liability.
When selecting a composite tactile indicator, TacPro® recommend the use of Marine-Grade 316 Stainless Steel with black Carborundum infills to ensure that the tactile indicators keep their colour-fastness as they never fade and maintain their anti-slip properties for years to come.
Also avoid tactiles that have a disc of self-adhesive carborundum tape pressed into a very shallow cavity on top - these invaribly fall out.