Hi geoff.
I use Lithofin mn slate seal.....good product.....
this is the instructions for its usage...
Manufacturers Instructions
Description:
A special product from the Lithofin range for marble, natural and artificial stone (MN). Lithofin MN Slate-Seal contains high-quality acrylates, suspended in organic solvents and it is ready-to-use. Lithofin MN Slate Seal provides a high gloss protective layer which prevents the penetration of water and dirt. It also heightens the colour of coated surfaces and makes them less susceptible to damage and easier to clean. Water vapour permeability is retained. The slip resistance is hardly affected. The coat is durable, it does not turn yellow and is conditionally weather-resistant.
Field of application and suitable surfaces:
Provides a high gloss seal for all absorbent, porous natural stone, particularly for internal applications. Particularly suitable for Indian or Chinese slate with a naturally rough surface. Not suitable for polished and fine honed surfaces.
Please Note:
Great care must be taken not to allow any wetness to permeate the sealed surface either from above or from below, to prevent the sealant turning white! Apply Lithofin MN Slate Seal uniformly with a foam roller or soft brush. In the case of strongly absorbent surfaces repeat process twice. Glass, polished surfaces and other solvent-resistant parts should be protected against splashes. Do not use in bright sunlight or in temperatures below 5°C or over 25°C. The application tools can be cleaned using thinner or white spirit. To remove Lithofin MN Slate-Seal we recommend Lithofin MN Power Clean.
Durability:
Used indoors - several years with correct care; used outdoors - depending on the support and the weather, about 1 year. If deterioration occurs, reapply. However, this product is not particularily suited for external applications.
Directions for use:
The surface should be absorbent, clean and dry. Non absorbent surfaces cannot be sealed. Apply to a small test area.
Coverage:
About 10m2/L, for multi-coloured riven slate and rough sandstone.
Drying time:
About 45 minutes at 20°C per thin coat.
If you don't want a high gloss finish you can use Lithofin stainstop mn...
Manufacturers Instructions
A spirit based, Silicon impregnator that penetrates into the surface of stone and forms an invisible film within the pores and capillaries. Prevents staining from water, dirt and oil, allowing the stone to breathe, and aids maintenance. For use on all polished and unpolished natural and artificial stone.
Description:
A special, ready-to-use product from the Lithofin range for marble, natural and artificial stone. Lithofin MN Stain-Stop contains silicones and hardeners that repel water and oil effectively. Lithofin MN Stain-Stop penetrates into the surface and forms a thin, invisible film in the capillaries. This stops oils from penetrating the surface for about 6-24 hours for marble and granite and up to 8 days for limestone. Within this time, it is possible to wipe away oils without leaving stains. The effect depends on the absorbed quantity of the product. Using Lithofin MN Stain-Stop does not usually affect the appearance of the stone, however, some intensification of colour may occur in darker stone types. It is UV-resistant (yellowing of stone will not occur) and dries without leaving a sticky residue. The active ingredients pose no health hazard after drying (please contact out technical team for more detailed information).
Field of application and suitable surfaces:
Lithofin MN Stain-Stop is used as a stain repellent for all marble, natural and artificial stone surfaces. Particularly suitable for walls and floors of kitchens, bathrooms and other areas at risk from staining, as well as for table tops, window sills and domestic surfaces. Polished and ground marble, polished and natural cleft limestone, slate, varying finishes of granite, reconstituted stone, artificial stone, terrazzo and resin bonded stone.
Please note:
With polished marble, red wine, ketchup or cola can cause etching. Never allow Lithofin MN Stain-Stop to dry on the surface, as it is not easily removed. Only to be used on absorbent and dry surfaces. Glass, ceramics and surfaces sensitive to solvents must be protected. A test area is advised before full treatment.
Directions for use:
The stone surfaces to be treated must be clean and dry. On an absorbent surface, apply generously and evenly with a brush or lambswool roller. On less absorbent surfaces apply with a brush or cloth. Within 30-40 minutes, treat the surface again to permit the impregnator to be absorbed. Then after 30 minutes remove any residue completely using a cloth. Over large surfaces, draw off excess material using a window rubber and polish using a using a Numatic scrubbing machine with a 3M polishing pad.
Coverage: dependent on absorbent properties of stone:
about. 15m2/L, for polished stone surfaces
about 6-8m2/L, for natural and sawn stone
about 3-6m2/L, for porous sandstone and limestone
Drying time:
preliminary drying: 2 hours (safe to walk on with smooth sole shoes). Complete drying: 24-48 hours (full effectiveness of impregnator).