Whether it is in the processing of stone products or in the construction of stone products, stone adhesives play an important role and are indispensable auxiliary materials in stone production, processing and construction.
However, due to the lack of training in the use of adhesives, the users do not know how to use the adhesives, and the stone adhesives are often misused in the Misuse of bonding leads to disease of the stone: the surface becomes yellow, blue, and adhesive spots; the adhesive does not dry for a long time; the bonding is not strong, and the stone and the substrate are easily separated; yellowing occurs in the bonding gap Change; glue penetrates into the stone surface; glue spreads to produce offset printing.
Figure 1 is a photo sent to me by a friend who is engaged in stone care work. When you see such a large yellow spot on the surface of the stone, ask a friend what caused it?
Ask a friend if the dry glue is cured, it is impossible to chemically react with the metal parts to make the metal rust.
The friend replied that this was his friend’s villa. In order to save installation costs, the friend handed the installation to a local construction migrant worker who had no knowledge of stone drying. These migrant workers have never used dry-hanging glue, do not understand the preparation of dry-hanging glue, sloppy when mixing the glue, and stir at will, without mixing the two components A and B evenly, use this unmixed When installing the stone with uniform AB glue, the glue will corrode the metal pendants, and the glue will seep up from the back of the stone, resulting in offset printing and yellow spot printing on the surface of the stone. Not to mention these untrained migrant workers engaged in building construction, even the installation staff of a formal building decoration and installation company will also make this mistake. At the installation site, they randomly find a piece of wood, plywood, or stone, shovel the dry hanging glue A and B components, the proportions are based on visual inspection, and use a shovel to mix the A and B components for a few times. The deployment of the glue used for the installation has been completed. This kind of visual ratio can be adjusted with a few random mixing of A and B components, genius knows. It is no wonder that many stone building decoration projects have the problem of yellowing of the stone surface, which has a lot to do with the inadequate blending of A and B glues and the failure to fully mix them evenly.
When working in a stone factory, the window sill panels processed by a well-known real estate in China had several batches of adhesive strips falling off due to the carelessness of the processing master. When the factory's after-sales service personnel went to the construction site to investigate the cause, they found that the glue was still wet, not solidified, and the glue did not form adhesion, so it fell off. One of the main problems of misuse of adhesives in the bonding process of stone products is that the glue does not dry for a long time and the bonding force is weak.
The misuse of stone adhesive shows the following situations
(1) Misuse of marble glue instead of dry hanging glue
Marble glue and dry hanging glue are two kinds of glue with completely different physical and chemical properties. The residual olefin bonds of the cured marble glue are easily oxidized and aged under normal conditions, and the durability is poor, and even the bond is broken and embrittlement. The cured product has low shrinkage and excellent durability; the curing process of epoxy glue is relatively mild and suitable for large areas. Process construction; due to the special molecular structure of the epoxy structural adhesive, its cured product has excellent chemical resistance and can resist corrosion by acid and alkali, salt spray, etc. The quality and effect of the two bonding are very different, and it should not be used Products bonded by dry hanging glue are bonded with marble glue.
The most common way for most stone processing enterprises and construction workers to use wrong glue is to use marble glue instead of dry hanging glue. There are deep reasons for this. Although dry hanging glue has good performance, it has a fatal flaw—the curing speed is slow and the time is long, which affects the production efficiency of employees. Especially in winter when the temperature is low, the curing time of dry hanging glue can be as short as half a day, and it may be as long as One day. No stone production company will provide a large area for production staff to spread out for bonding, so that the production staff have to wait for the dry hanging glue to cure before moving the product. The low output in a day causes the employees to be reluctant to use dry hanging glue for bonding. For stone products, use marble glue to bond stone products with fraud. As for the construction staff of building decoration enterprises, it is even more troublesome. If the dry hanging glue of the lower layer of stone products is not cured and the upper product is installed, if the lower layer of the product appears because the dry hanging glue is not cured, it will be disassembled after reinstallation. The upper product is a waste of time. Some stone processing business owners ask their employees to use marble glue instead of dry hanging glue for cost considerations. After the product is bonded, the glue is concealed in the inner product, and the customer cannot see it.
(2) Use inferior glue
There are many brands of stone glue, good and bad, and prices vary greatly. The price and quality of the glue basically correspond. The high-priced glue is of good quality, and the low-priced glue is of poor quality. Poor quality glue will not only have poor bonding strength and yellow glue quickly, but will also cause various lesions of the stone, which will make the stone ugly after installation and affect the decorative effect. In July 2018, when processing the Xi’an Garden Conference Center project, I used some relatively cheap dry hanging glue. When using it, it was found that the glue would turn yellow, and the glue seam would turn yellow completely within a few days, making the bonding The appearance quality of the products that came out was very ugly, so I had to cut off all the bonded edges of the products that had been bonded with cheap glue and reprocessed them, which wasted a lot of time. The cheap images increased the cost. The repair of the stone surface should be treated with glue more seriously, because some inferior glue will spread on the surface of the stone, resulting in "oil spots" similar to Figure 4, which will affect the appearance of the stone. Some materials with loose materials, such as Jazz White and Ash White, which are easy to spread, should be selected carefully. Wrong selection of glue may cause a large number of "oil spots" on the surface of the board.
