After quarrying, milling and then packing a black limestone it is possible for residues of moisture and sediment to remain on the surface. If left over a period of months these deposits of mineral and sediment absorb into the pores of the stone. This type of staining can be very difficult to remove using conventional cleaning materials. The following is a guide to help restore the appearance of the stone using a strong cleaner and then sealing to restore and enhance the colour.
1. LTP Grout Stain Remover is applied and then immediately scrubbed into the surface using a black emulsifying pad. This should be done for 1 – 2 minutes making sure to cover the whole surface of the stone. This cleaner will slightly etch the surface of the stone to release the stains from within.
3. Once dry, surfaces will appear grey rather than black. The stains should no longer be visible. The surface of the stone has been conditioned ready for sealing.
4. Apply a small amount of LTP Stone Oil to the surface of the Limestone and spread out evenly. Leave to absorb into the surface of the stone for 1 hour. Any visible excess after this time work should be worked off using a soft absorbent towel.
5. The sealer should be left to dry for a minimum of 24 hours with light traffic only.
It will take a further 3 days to reach full hardness, so surfaces should be kept as dry as possible during this time.
Finishing the stone with a light coat of LTP Mattstone should be considered if the stone is to be used in kitchen areas.
This should be done after fixing and before sealing and grouting to remove calcium carbonate and mineral deposits including dust and dirt that has accumulated during the production and fixing process. Apply undiluted solution to the surface of the stone and agitate immediately with an emulsifying pad. Rinse thoroughly with a separate pot of clean fresh water. Wipe away the released calcium dirt and grime with a mop or sponge and water and leave to dry for 24 hrs.
Before grouting apply a light coat of LTP Stone Oil, check that all of the sealer has been
fully absorbed within 1 hour, any excess that remains on the surface after 1 hour should be worked in with a soft cloth or buffing machine. Leave for a further 4 hours or overnight before grouting the joints. Once all residual grout has been removed and the surface and joints are thoroughly dry; apply a final light coat of StoneOil covering the joints as well. Buff to remove any excess within 1 hour and then leave for a minimum of 3 days to fully harden before making excessively wet.
When cleaning or sealing vertical surfaces always start at the top and work down.