Silicate primer is used as a base coat for long-lasting paintwork on masonry walls. Apply one coat of SecilTek Silicate Primer and two coats of SecilTEK Silicate Masonry Paint. SecilTEK Silicate Primer is easy to apply with a brush or roller and dries in hours (although we advise applying no more than one coat per day). It can be used internally or externally on a wide range of mineral surfaces including lime and cement renders, gypsum plasters and stonework. Its also ideal for problematic areas such as damp basements.
Silicate masonry paints have an interesting history. They were designed at the behest of King Ludwig I of Bavaria in the last 18thCentury. Ludwig commissioned a paint that looked and worked like limewash, of which he was a great admirer, but was more durable in the harsh winter climate. The small pore size of silicate paints still allows high water vapour permeability, while at the same time these small pores don’t allow the larger rainwater molecules to penetrate. There are instances in Germany of silicate paints lasting 100 years !
Like limewash, silicate masonry paint soaks into the mineral substrate. In addition to this, the potassium silicate (waterglass) reacts chemically to form a microcrystaline bond; a process known as silicification. Silicate paints have a comparable thermal expansion co-efficient to a mineral substrate. This minimises the stresses and damage caused by differential expansion.
(*Note: Please contact our technical team for advice when considering the application of SecilTEK Silicate Masonry Primer and Paint over conventional ‘plastic’ masonry paints)
What’s an Sd value?
This refers to the resistance shown by the equivalent thickness of air, so the lower the Sd value the greater the breathability. Paints with Sd values less than 0.1m are considered to be highly breathable. SecilTEK Silicate Paint has an Sd value of 0.01 m!!