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Basic Guidelines For Restoration Of Marble Tops
The following guidelines make reference to “average’ situations. This means that there is no way of establishing beforehand what the exact sequence of the various steps will be. Much will depend on the type of stone, the contingency of the situation, i.e. the depth of the scratch patterns or severity of the etching, etc.
Keep in mind that the following guidelines are not written…in stone!
Two-Step Procedure: Honing and Polishing Marble Vanity Tops 1
The definition of marble makes reference to calcite-based stone that are traded as marble. Stones that are still traded as marble, but are not calcite-based (serpentine, ophicalcite, etc.) are not part of this group. Dolomitic marbles can be part of this group, providing that the final polishing is going to be made “hotter” than average.
Bear in mind that when restoring a marble vanity top you will have to deal with encumbrances such as faucets, stoppers and backsplashes or drop-in sinks. It is important to let the customer know at the time of estimate that the areas immediately near the faucets and stoppers will not be restored as properly as the rest, unless the faucets and the stoppers are removed before the commencement of the job. In the case of a backsplash or the rim of a drop-in sink, if there is damage (a scratch or a severe etch-mark) that reaches up to these places, it will be technically impossible to restore it completely because the overlapping of steps necessary to complete the job will not be possible.Before you start the job, be sure to mask all surrounding areas that could be damaged by splatters, including the front of the cabinets the vanity is sitting on and the floor near it.
1st Step – Honing
It is recommended to use wet-diamond honing pads, on a 4” diameter flexible pad holder. There is no way to pre-determine which grit you should start with. It could be just a light honing with, say a 400 grit and the polish. Or the situation may require you to start with a 50 grit resin-bond, or, in the most severe situations, with a 60 grit metal-bond pad. It is usually possible to polish after 400 grit, but certain dolomitic marbles, i.e.: White Thassos, Brown Emperdor (light or dark) will require a higher grit (800 or 1500) before polishing. The same general principle of keeping the polishing slurry “hotter” with these types of marble applies also in the case of a vanity top. Very delicate marbles (like Botticino) will need to be brought up to 1500/1800 grit before polishing, but the slurry must be kept “lukewarm”, or else they will “burn”.
2nd Step – Polishing
You can either “wet-polish” or “dry-polish” with a white nylon pad on the 4” or 7” backer pad.If you choose the wet-polishing method, sprinkle some polishing powder in the middle of your targeted area (shouldn’t be more than 2 to 4 square feet) so it will all be contained under the polishing pads. Add plenty of water with a spray bottle, place your polishing pad on top of the wet powder and polish at the lowest possible speed. Check with a squeegee to see if that area is polished, then pick up the slurry swiftly with a masonry sponge or other appropriate means. Proceed to the adjacent area, making sure to overlap into the previous area.If you choose the dry-polishing method instead, sprinkle a little bit of polishing powder rated for “dry-polishing” in the middle of the area where it will be contained within the polishing pad. Sprinkle water onto it from a spray bottle according to the “heat” that you need to produce and depending on the type of marble. Place your polishing pad on top of the wet powder and, with the machine pre-set at approximately 2500 RPM, start polishing keeping the RPM to a minimum by controlling the speed with your fingertip and swiftly spreading the slurry over your targeted area, no more than 2 to 4 square feet at a time. As typical of the dry-polishing process, the first area done with a new pad may have to be done twice. As you proceed, the amount of powder per section will decrease because you will be using powder that has stuck to the pad that’s still active. As the slurry becomes almost dry (to the point of not splattering any more), pull the trigger all the way and polish the targeted area, keeping a swift pace all over it, until it is nicely shined and dry. Repeat the procedure in the next adjacent area; don’t forget to overlap the previous one a little.
Note: With dolomitic marble like White Thassos or Emperdor (both dark and light), wet-polishing will not always produce a factory finish; White Thassos may “orange-peel”, while Emperador may appear hazy all the time. Only dry-polishing can produce a factory finish (or better) all the time with those kinds of marbles.
For more in depth instruction of restoring marble tops, order our Natural Stone Maintenance and Restoration Book. Also - consider attending one of our Stone Restoration Training Classes in Wilson, NC.