Brand: RA&Sons

RASTRENGTHENER is a premium eco friendly VOC-free stone sealer ideally suited to masonry, stone and traditional lime based plasters. RASTRENGTHENER’S unique formula means it actually strengthens as time passes and its high resistance to alkalis make it perfect to control the absorption of humidity in walls and ceilings, it can be used as a finishing and protective coating both internally and externally. RASTRENGTHENER is available in 1L, 5L and 25L plastic containers.

Surface Preparation

Ensure all new or old surfaces are sound, clean, dry and free from flaking paint, grease and similar contaminants. Mold or algae growth must be removed and treated. There should be no paint present on the surface to be treated.



Apply RASTRENGTHENER undiluted to the substrate with either a brush or roller, one even coat is sufficient. If a sheen is required apply a second coat. Clean tools after use with water. RASTRENGTHENER is clear but will change the colour of the substrate slightly.



  • With temperatures below +5°C or above +35°C
  • Do not use on wet surfaces
  • Do not use on gypsum or gypsum boards
  • Do not use on painted surfaces
  • Do not use on glass or metal
  • Protect floor coverings, furniture and personal effects

Mineral Reinforcing Consolidant

Packaging & Storage

RASTRENGTHENER is supplied in 1L, 5L and 25L plastic containers and can be stored up to 12 months in a cool dry place, in its original unopened packaging

Safety Notice

Before using RASTRENGTHENER it is recommended to consult the product safety data sheet available on request

Technical Data

Type of Binder
Potassium Silicate
1.16 Kg/L21.5%
15 m²/L
The data and statements in this information sheet refer to laboratory tests in our possession, conducted in standard environmental conditions. Practical applications on site according to these conditions of use may result in different data readings. Due to the wide variety of possible uses and applications, the end-users should independently determine the suitability of the material for their specific purpose prior to use. R.A. & SONS Manufacturing Ltd. reserves the right to make technical modifications of any kind without prior notice.

Other Products

© Copyright RA & Sons Ltd 2024