Faulty putty is also called find putty, repair putty, delicate putty and so on. It is mainly used for leveling the surface of intermediate paint or scraping the last putty such as the top coat.
For the scraping of defective putty, first of all, the appropriate type of putty should be selected according to the painting production conditions. Such as construction under normal temperature conditions, in order to speed up the construction progress and improve production efficiency, putty or nitro putty should be used. If it is a large-volume painting production line, and the construction station and drying room are ample, it is recommended to use amino drying putty or alkyd putty, which will not only facilitate the scraping construction, but also ensure the quality of scraping. However, when the work stations and drying rooms of the large-scale painting production line are tight, in order not to affect the production progress, nitro putty should also be used, that is, after the putty is scraped for 10 to 20 minutes, it will be sent to dry without affecting the construction schedule.
The specific scraping method is a very meticulous operation. When scraping, you should follow the light to effectively find and smooth the small defects such as sand marks, pinholes, and pockmarks on the surface of the paint film, so that the base layer is very smooth and lays a good foundation for the topcoat. Therefore, a small steel scraper or ash knife should be used on the scraping tool to facilitate scraping construction. When scraping, usually each side needs to be scraped several times along the light, so that the defects can be easily found and smoothed. Every time you scrape and apply a piece, you should immediately clean up the surrounding residues to prevent the residues from drying out and adding trouble to polishing. If you use a wide scraper or a wide ash knife to find faults, since the surface of the fault is extremely small, not only is the putty wasted, but also the scraping area is large, which will affect the working hours and prolong the grinding time.
Another point that should be noted is that water quality putty or thick cooked tung oil gypsum putty should not be used to find faults. Because these two kinds of putty are thick, they have good filling and leveling performance for large depressions and other unevenness (that is, thicker putty can be scraped at one time), but they have poor filling and leveling performance for small defects such as pinholes, sand marks, and pockmarks . The surface is rough, so special care should be taken.
