Is the black spot on the surface of the water-based paint mildew? - Ask the water-based paint expert Problem: The wooden doors of our company's surface veneer have no black spots before they are painted. After spraying the water-based paint (primer + top coat), black spots appear on the veneer during the natural drying process. I wonder if the water-based paint is mildewed? If the oil-based colorant is used to seal the bottom, will the water-based primer finish avoid such problems? Response： According to your description and photo analysis, the phenomenon you are experiencing is not the mildew of the waterborne wood, but the chemical substrate of the wood substrate you use. This is because there is no black spot in the wood. This is the case when the wood is unevenly colored, and when it is dry, it will be swollen with water or the solution will swell. Most wood is chemically treated. Black spots do not occur when the chemical treatment is good. However, in some cases, such as excessive hydrogen peroxide accumulation or unidentified stains, there will be black spots on your picture. We recommend that you try to wash the surface of the wood with water or sprinkle, and then dry the paint. We feel that after solving the problem that the substrate is not clean, the problems you encounter can be solved. For wooden doors that have been painted, only remove the paint and clean it. Sealing the bottom with an oily colorant and applying a waterborne primer finish may not solve your problem. This still depends on the substrate. If the substrate is not clean, black spots may occur, but the solvent has little effect on the fiber, and the black spots are not so obvious. I hope our answer will help you. If you have more specific requirements, you can contact us directly. For more information on waterborne coatings, you can also visit sinograce chemical's waterborne coatings knowledge base and recipes in our waterborne formula library. Or ask us directly through our question water-based paint expert column. Sinograce Chemical produces water based coating,Water-based glue, polyurethane coating,Acrylic solution. visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511

Is the water-based wood paint film as hard as possible? In the market of waterborne wood lacquers, hardness is one of the most concerned indicators for many Chinese waterborne paint developers and users.In the traditional concept, the harder the paint film, the better. There are often customer consultations for ways to get the paint film to 2H or even 3H.Although waterborne wood lacquers have improved in performance over the past few decades, their hardness is still not as good as solvent-based paints. As a water-based paint developer, if 2H and 3H are set as the criteria for successful research and development, most of them will be futile for many years and will be ineffective.I am afraid that the problem we need to pay more attention to is not "how to increase the hardness of water-based wood paint film to 3H?", but "Is the harder the water-based wood paint film?" In Mr. Zhu Wanzhang's "Research and Measurement of Hardness of Waterborne Wood Coatings", there are some discussions about the excellent hardness of waterborne wood coatings. Mr. Zhu pointed out the following points: 1. Hardness reflects the ability of one material to resist, indent, scratch, and penetrate another material. 2. Hardness and scratch resistance and abrasion resistance: Wear is the result of peeling off the material from the solid surface under the action of force when the two solid surfaces are in contact. The force received during wear has shear forces in addition to the positive pressure. A relatively soft surface is more susceptible to scratching when the two materials are in contact with the surface. The scratch resistance reflects the surface properties of the material under the action of large stress and short time. Scratch resistance is not only related to the hardness of the material, but also to the toughness of the material. Abrasion resistance describes the extent to which a material peels off from the parent under the same stress conditions (temperature, humidity, contact medium, magnitude of external force, and time of stress). As with scratch resistance, wear resistance is related to the hardness and toughness of the material, but the wear resistance reflects the surface properties of the material under the action of small stress for a long time. 3. The harder the coating film is, the better the abrasion resistance is. On the contrary, for the same type of polymer coating film, it has been found that the harder the coating film is, the worse the abrasion resistance is. In fact, the flexible coating has better wear resistance. Conclusion: As a coating, a hard and tough coating is the best coating. Among Sinograce Chemical's waterborne resin materials, PU-106 Aromatic polyurethane dispersion is an excellent waterborne polyurethane resin with medium hardness and toughness requirements. It is an excellent choice for high-grade waterborne wood lacquer formulations. If the formulation cost is critical, the PU-106 Aromatic polyurethane dispersion can be used wit...

Problem：I have not done waterborne polyurethane, the waterborne paint is a rookie .I have never done water - based, water -based is a rookie，I wonder if waterborne polyurethane also needs curing agent? If you want to use it, what is the ratio?Because of the presence of water, is it possible to go back and consume the curing agent?And I want to use this to make the electroplated silver, is it ok? Response：Waterborne polyurethanes do not necessarily require a catalyst. In fact, waterborne polyurethanes are primarily designed for single component coatings.In other words, the resin itself has a high molecular weight .This is essentially different from solvent based polyurethane coatings. Good quality polyurethane gloss can reach over 90.In more demanding applications, it is necessary toadd small amounts of crosslinkers.However, most of these cross-linking agents are not isocyanates, and the crosslinking mechanism is different, and does not react with water. For the application of electroplating silver, please contact our company, we have protective products for electroplating field . Sinograce Chemical produces water based polyurethane emulsion products and related chemical additives, welcome to inquire, we will recommend suitable waterborne polyurethane products according to your production needs. visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone               :+86 0551 63459511

PH adjustment of water-based paint-Ask water character paint expert Question: If the pH value of the water-based paint is not weakly alkaline or the pH value is unstable, what effect will it have in actual use? Thank you! Response: The unstable pH of water-based paints has two main effects on water-based paints.One is that it affects the stability of the filler or paste in the resin because the pH of the system affects the surface chemistry of the particles and affects the dispersibility or degree of bonding of the particles. In severe cases, it will cause gel or bean curd.Second, it will affect the role of the system and the substrate.For example, for waterborne wood lacquers, some woods will exhibit different colors due to the pH of the coating. Alternatively, for aqueous anti-corrosive paints, the pH on the corrosive metal surface greatly affects the corrosion resistance of the water-resistant anti-rust paint . I hope our answer will help you. If you have more specific requirements, you can contact us directly. For more information on waterborne coatings, you can also visit Sinograce Chemical waterborne coatings knowledge base and recipes in our waterborne formula library. Or ask us directly through our question water paint staff . Sinograce chemical produces water based metal paint, water based metal protective paint, metal anti corrosive paint and metal anti rust agent, with good resistance to salt fog, weather resistance, antifouling, corrosion resistance and rust resistance, anti corrosion paint price is reasonable, welcome to inquire. visit us sinograce chemical: https://www.sinogracechem.com Get a Quote Now :sales@sinogracechem.com Telephone            :+86 0551 63459511