Grinding and Polishing Natural Stone
There are several main categories of stone that are commonly used for floors.
They are: Marble, Granite, Travertine, Limestone, Slate and Quartz.
The finishes commonly used are Polished, Honed, Brushed, Flamed, Split face and Antiqued.
There are many types of sealers and coatings that are also used which will affect the appearance of the stone.
Some of these are penetrating sealers which have no color change or gloss, Color Enhancing sealers which darken the stone and may be penetrating or be a surface coating, and Topical Sealers which are essentially a coating which will provide varying degrees of gloss and color enhancement.
In this section we will focus on grinding and polishing of natural stone.
See below for step-by-step instructions on how to grind and polish natural stone
Grinding and Polishing Granite
Grinding and polishing granite can be a challenge due to the hardness of the stone and the crystal structure, however there are ways to alleviate some of the problems associated with these factors.
For example, when grinding some granite there is a lot of micro-pitting produced as some of the crystals are released from the stone.
This can be greatly reduced by using a higher grit and going over the floor slowly and with more care.
Although this may take a little longer in the beginning, the end result will be a much higher shine and more uniform appearance.
For very hard granite it may be necessary to start grinding with 100 grit to “open” the stone then go to 50 grit then 30 grit and then back to 50 grit and finally back to 100 grit and then continue with honing and polishing.
If you are unfamiliar with the stone it is always recommended to do a test piece if available or a hidden section to determine the best procedures.
Following is our basic system for granite. This system is for professionals who already have experience and know how to refinish Granite.
How to Grind and Polish Granite
STEP 1 – Lippage Removal – For rapid Lippage removal load your Rhino grinding machine with 30/40 grit Titanium Metal Bonds. Start at the lowest speed and increase if necessary until optimum cutting action is achieved.(for minor Lippage start with 60/80 grit Titanium)
STEP 2 –Continue with 60/80 grit Titanium Metal Bonds and remove all 30/40 tool marks and any remaining Lippage. Clean floor thoroughly.
STEP 3-Transition using the 100 grit Shark Pad to provide a smooth and uniform surface. Clean floor thoroughly.
STEP 4 – Go to 100 grit WaterGloss Pad. Clean floor thoroughly.
STEP 5 – 200 grit WaterGloss Pad. Clean floor thoroughly and allow to dry.
STEP 6 – Apply a thin even coat of pore filler and hardener and allow 2 hours to dry.
STEP 7 – 400 grit WaterGloss Pad. Clean floor thoroughly.
STEP 8 – 800 grit WaterGloss Pad. Clean floor thoroughly.
STEP 9 – 500 grit WaterGloss Pad. Clean floor thoroughly.
STEP 10 – 3000 grit WaterGloss Pad.
STEP 11 – Clean and finish using the 3000 grit Mamba Pad.
FINISH – Apply a penetrating sealer, an enhancing sealer, or for high traffic areas in a commercial application, a thin coat of Proguard Coat n’ Seal can be used to protect the polished surface from wear.
- Dust mop or vacuum daily or as needed.
- Damp mop or autos rub using applicable neutral cleaner.
- When using ProGuard Coat n’ Seal — burnish periodically and re-coat if needed.
Marble – Travertine & Limestone
There are many different types of Marble, Travertine and Limestone encountered. All of them can be professionally refinished using the Rhino and our HyperGlosstools.
The difference between harder or softer stones will be accommodated by adjusting grit, weight and speed of the machine. Our system is recommended for professional contractors who have enough experience to properly assess the floor and make the necessary adjustments to the machine and system if needed.
How to Grind and Polish Marble, Travertine & Limestone
This system can be used for lippage removal, deep scratches or fine scratches and dull areas. The user will determine at what grit and what step to begin the process depending on the condition of the floor. Floors with sanded grout will generally require the grout to be cut down and unsanded grout installed prior to polishing. Please note the dry steps listed my also be used wet.
Step 1 – For lippage removal and deep scratches. Install 30/40 Titanium metal bonds (for severe lippage start with 16/18 Titanium metal bonds and then proceed to 30/40). Run Rhino machine at low speed and cross hatch floor to remove lippage and flatten floor. This step may be run wet or dry
Step 2 – Install 100 grit Shark pads and cut floor down to remove scratch pattern from first cut (for most Travertine’s apply filler after this step and allow to cure)
This step may be run wet or dry
Step 3 – Install 200 grit HyperGloss pad and cut floor evenly at low speed. This step may be run wet or dry. If running dry on Travertine, mist floor in the areas that have been filled to facilitate removing excess material
Step 4 – Clean floor thoroughly by vacuuming, damp mopping or auto-scrubbing. Apply hardener such as ProGuard Pore filler and allow minimum 1-2 hours to dry
Step 5 – Install 400 grit HyperGloss pad and remove excess hardener and evenly hone floor. On some floors it may be necessary to use some water so as not to have resin transfer from the tool to the stone
Step 6 – Install 800 grit HyperGloss pad and do one complete pass over entire floor surface at 800-1200 RPM
Step 7 – Install 1500 grit Mamba pad and run dry over entire floor surface while connected to vacuum, this will clean the floor and remove dust
Step 8 – Polish the floor using 3000 grit Mamba pad and run dry to produce a high quality shine
Step 9 – If floor has sufficient gloss proceed to next step and apply sealer – If a higher gloss is required please use standard polishing powder or cream and a polishing pad – or, use our HyperShine pad on a floor machine or high speed burnisher
Step 10 – Apply penetrating sealer and remove excess and allow to dry. For heavy traffic and/or commercial applications apply ProGuard coat and seal
How to Grind and Polish Slate
Not all Slates are suited to grinding and polishing. For instance, some of the layering in certain types of Slate will cause delamination if ground. Very soft Slate will not accept a high polish and can only be honed. Usually only hard solid bodied Slate that has been gauged is recommended for polishing. The general grinding and polishing steps are the same as for Marble – Travertine and Limestone. (See basic system for Marble – Travertine and Limestone)