Flexiguard is a liquid quartz water-based nano-coating designed to protect porous stone from staining caused from dirt and grime in the environment, but how can you be sure it works?
Flexiguard is tested according to ISO 11507 Artificial Weathering methodology in order to measure its active longevity under accelerated UV conditions. Sunlight or more specifically UV light rays cause many stone and paving sealers to degrade rapidly– reducing their ability to repel dirt and stains in the long term, therefore requiring regular reapplication.
Independent testing of Flexiguard under the ISO 11507 protocol measure and verifies performance. The repellent nature of the coating is determined by the contact angle Θ of the edge of distilled water droplets every 500 hours within an overall period of 3500 hrs.
Results are impressive , in that the coating showed an ‘increase in the contact angle Θ from 131.6° to 147.9° after an exposure time of 3500 hrs. A possible interpretation of this behaviour is the chemical post-crosslinking of the coating. Essentially, this means that through prolonged exposure to UV light Flexiguard continues to cure and become more effective at repelling liquids and dirt.
The accelerated conditions of the tests are equivalent to at least 3 years ‘normal’ UV weathering.
A competing fluorocarbon coating marketed by a leading concrete manufacturer was tested to the same standard at the same time – it lost more than 50% of its repellence after 500 hours (6 months equivalent approx.) and would no longer be considered hydrophobic as its water bead angle was only at 50° (hydrophobicity is classified as above 90°). Flexiguard has demonstrated an actual improvement in performance after an additional 3000 hrs.
Laboratory tests provide an indication of performance – but ‘in-field ‘or ‘in-garden’ testing demonstrates ‘real life’ performance. To this end, a sandstone sample was half coated with Flexiguard and then returned to the garden to be weathered – seventeen years ago!
After 17 years functionality it’s possible to clearly see the darkened untreated right-hand side, where dirt and grime have become ground-in. The treated left-hand side only requires the soil to be brushed off for it to look pretty much as it did when was new and first coated.
Flexiguards’ weathering resistance is achieved without the use of fluorocarbons. It’s water based – so kind on the environment as well as your pocket! One coat demonstrably has functionality in excess of 10 years as our ‘in-garden’ test can verify.