Determination and thickening scheme of specific gravity of bakelite varnishes for leaching

When non-ferrous metal castings have leakage defects, the method of dipping Bakelite varnish can be used to repair the defects. The bakelite varnish used for dipping is generally made of 50% cresol (carbolic acid), 50% formaldehyde (formaldehyde), and a small amount of ammonia water. According to the application method, the specific gravity of the liquid of this leaching material must be in the range of 0.95~1.03, in order to achieve better results. However, after the Bakelite varnish has been used for a period of time, the density will increase. If the specific gravity exceeds 1.03, distilled alcohol should be added to dilute it at this time, so as to ensure the quality of casting repairs. Take a graduated cylinder with a capacity of 250 cubic centimeters, pour the paint into the graduated cylinder to the point of 250 cubic centimeters, and then put a liquid specific gravity with a minimum scale value of 0.005 into the paint, and then the specific gravity of the paint can be drawn from the side (the temperature of the paint should be determined from the side) at 16~20°C).