Stone Polishing – How to Restore a Stone’s Gloss
While some natural stones may look pristine once installed, the truth is most surfaces require regular polishing to maintain their luster. Restoring a stone’s shine can be done by the owner or a professional.
Most stone is polished by tumbling it in a barrel with progressively finer grades of abrasive, for days and sometimes weeks. The stones are washed carefully between each grit to avoid introducing scratches. Get more info.
Stones are polished in a variety of ways to create one-of-a-kind gems and cabs. Each polishing procedure has its own advantages and disadvantages, but all methods will produce a polished stone surface when used properly.
Before starting to polish, test the stone to make sure it’s hard enough by scraping a small area with the tip of a pocket knife. If the mark left by the knife blade is gray or white, it’s too soft for polishing.
Next, wash the stones and barrel by removing both end caps and washing them carefully. Now re-tumble using the same proportions of grit and water but this time use 400 grit. This is an important step and will determine the final polish so do not skip it to save time.
Stone surfaces can be polished with a variety of methods, but all achieve the same goal – to reduce the stone’s ability to absorb liquids. This aids in stain prevention and can greatly enhance the beauty of a stone.
Large quantities of rough stones are tumbled – turned slowly in a barrel filled with water and sand for days or weeks. By washing and tumbling with progressively finer grades of abrasive, stones are polished to serendipitous shapes.
Examine the stones carefully and discard those with jagged edges. Skipping grit sizes to save time may lead to extensive scratches in the final polish. This example of convoluted jasper contains fossil coral that has been replaced with agate (agatized). The material is very colorful and highly reflective, but it shows some rough areas that could have been smoothed out with another 320-grit tumble.
Stone surfaces lose their shine with wear and tear over time, and it’s important to refinish them to keep them looking like new. Refinishing can be done at home or professionally, and the process is relatively simple.
The basic idea behind polishing is to rub a harder stone against a softer one. The harder stone is often a rock, but sandpaper and even powdered metals can be used to get the job done.
A rotary tool (like this Dremel set) is perfect for this kind of project. Thoroughly clean the barrel and stones by removing both end caps and washing them carefully. Start with grit, working your way through the different sizes. Skipping a grit size to save time could make your final result worse.
When a stone surface becomes dull and lacks luster, the crystals within the stone that reflect light become crushed and worn down. Only by polishing can the luster of natural stone be restored.
Once the stone is honed to remove very light etches and scuffs, it is ready for a high sheen. This process uses a diamond pad with a lower grit level and produces a smooth, natural-looking sheen.
To help protect your natural stone after the process, our Granite Heroes will apply a penetrating sealer to your shower, countertop, or floor. There are a number of different sealer options available. Ask your Granite Hero for details.
A polished finish displays all of a stone’s colors and crystalline structure. It also increases compression strength and resistance to dents and chips. It is also naturally resistant to disease-causing microbes.
To polish, the stone is tumbled with gradually finer grades of grit until it shines. These grits are usually aluminum oxide, cerium oxide, tin oxide, or diamond powders.
After the tumbling process with 160 grit is finished, wash and dry the stones, and then use 220 grit to smooth out the larger scratches left behind by the coarser paper. This should run for no more than five or six days, and the results will be very noticeable. This is a very important step in determining the final shine, so do not skip it. Definitely worth checking out!