1. First of all, buy good quality putty.
2. Secondly, putty and water should be mixed in an appropriate ratio, and then stir evenly.
3. Then, clean the base of the wall and apply putty.
4. Finally, scrape three times. Each time you have to wait until the putty is completely dry before scraping the putty for the second time. The thickness is best controlled at 2 mm.