Stone inclusions, calcite texture, glass-like or cloud-like structure, or diversified components are usually the places where natural stones attract people, not the places where people complain. However, the cracks and holes in natural stone are undesirable. These cracks and holes will inevitably be complained by people, especially the black stone and similar stones, which are dazzling in every irregular place. In this article, we will talk about black stone processing technology and protection renovation.
● Black stone processing – strengthening and polishing:
When these plates are further processed, such as when they are made into kitchen countertops, the final polished corners maybe another color, usually lighter than the surface color. This is because the epoxy resin cannot penetrate the whole slate.
In this case, a special product that can deepen the color of the black stone can be used. The stone’s heavy color protective agent can ensure that the natural stone has a high-quality penetration protection effect at the same time. It can be applied to the whole kitchen countertop, floor, and stair-step countertop. The black stone will lose its elegant appearance and high-quality appearance if it is not polished but treated in other ways. If “Shanxi black”, “Panama black” or “all over the sky star” are subject to anti-skid treatment such as sandblasting or heat treatment, they will be grayish-white and look unobtrusive.
After cutting and processing, these stone slabs cut from the waste materials are cleaned, roughened, heated, and coated with a layer of black epoxy resin adhesive with very low viscosity. This leveling can penetrate very fine capillary cracks and holes, strengthen bonding and ensure that the surface of natural stone materials is sealed. After curing for about 24 hours, these slabs can be further ground and polished. Due to the relatively long curing time of the epoxy resin adhesive, the color of the treated stone is deepened more or less.
In the above industries, the processing of black marble or limestone is relatively small. The reason is that the scrap rate of the final products produced by these stones is quite high. These kinds of soft black stones are often full of calcite texture or very fragile due to their natural holes and cracks. Therefore, it is usually impossible for these stones to produce large plates.
To process this kind of stone in a relatively economic range, the back of the stone plate should be strengthened. A flowable epoxy resin adhesive is applied to the back of the whole unprocessed slate. Then stick the glass fiber back net on the adhesive coating and apply the second layer of epoxy resin adhesive. When the reinforcing layer is cured, the front of the rough board can be filled. Since marble and limestone are only suitable for indoor use, these holes and large pores on the surface can be filled with a fast-drying polymer resin product. After a few minutes, when these products are cured, the stone can be ground and polished.
● Penetration protection of black stone
When dealing with many kinds of black stone, the penetrant will cause the change of stone color, which is usually the effect that needs to be achieved.
For these sensitive natural stones, a special penetration protection product nano antifouling agent should be used. Remove the excess material after 5-10min. The penetration protection effect can be completed in the only 2H. The product will not cause a change in stone color.
● How to grind and renovate the black stone
● Reason for the whitening of black stone
1. Insufficient grinding optimization
The primary reason for the whiteness of black stone is three words: not polished well. It should be pointed out that it is forbidden to skip numbers when grinding black stones. If the number jumps, there will be a situation of “unable to hold the number”, which means that the scratch left by the next level grinding plate cannot hold the upper-level grinding plate, and it must turn white.
2. Black stone can’t cover scratches
The scratches on any stone are white. This phenomenon is determined by the optical principle and has nothing to do with material and color. Therefore, the ability of the black stone to cover scratches is the lowest. Grinding scratches caused by coarse particles of grinding plate and scratches caused by sole gravel are easy to make black stone gray and white.
3. Black stone is easy to be polluted
Black is a color with strong contrast. Dust, stains, and pollution are easy to appear on black stones, resulting in gray and white visual effects.
4. Relationship between “color” and “luster” of stone
Stone color comes from the natural color of the minerals contained. Therefore, the black of stone mainly depends on the natural color of its minerals. The higher the gloss, the brighter the color of the stone.
● Solution
1. Do a good job of protection
The black stone is easy to be polluted by dust, pigment, and other substances, so it should be well protected.
2. Grinding optimization should be done well
In the grinding optimization stage of black stone, it is necessary to continuously cross grind more than 3 times. The more times, the more uniform, and the clearer the background color of the stone.
3. Prevent scratches
① During construction, prevent gravel or hard objects brought by external factors from scratching the ground.
② Clean the mud on the site and the mud of the machine itself in time to prevent the debris from scratching the ground and keep the ground highly clean.
③ Prevent coarse-grained scratches on the grinding plate. Solution: when grinding, if there are prominent particles on the grinding plate, remove them with a needle or blade.
Well, this article will be written here first. If you have more good suggestions on black stone processing technology and protection renovation, I hope you can send me an email at sales@sntstone.com.
