What are the commonly used coating sealants? What is the purpose of sealing?

       The coatings obtained by most spraying processes are porous. After the coating has been sealed, it can prevent the coating from falling off the grinding wheel and the pores in the contamination layer of the abrasive particles. Can be used as cutting lubricant.



    When spraying ceramic powder as an insulating coating, if the pores are exposed, moisture or dust can be drawn in, creating many conductive paths in the material, reducing the insulating properties. Paraffin seals pores and keeps the insulating properties of the coating intact. In the case of high temperature work, inorganic sealing agent should be considered. Such as hydrolysis of ethyl silicate, etc.

    Another purpose of sealing the coating is to improve the corrosion resistance of the coating. For example, alumina coating is a porous coating that can be sealed with phenolic resin to enhance corrosion resistance.

    Commonly used sealing materials are paraffin, liquid phenolic resin and epoxy resin. Inorganic sealing materials include water glass and hydrolyzed ethyl silicate, both of which are not very good coating sealing agents and are generally not recommended. ,

    The surface of the coating must be clean and dry before applying the sealant. It is best to seal the hole immediately after spraying, so as not to adhere to the surface of grease. If there is grease, it must be washed with a suitable solvent and evaporated before the coating operation.

    In order to obtain a satisfactory sealing effect, the coating method of vacuum injection sealing agent is sometimes used.