Ask the master to smear it.
Please master daub it. Scrape (clean) the wall first, scrape up the mixed putty powder, and then smooth it when it is dry. Then you can apply cement paint. After the first drying, you can apply it twice, which is very white and guarantees the quality!
Buy plaster
You can buy gypsum mortar and use it directly. Plastering mortar is generally produced by retarded soil additive factory and some artificial cultural stone factories with their own registered trademarks. Because these enterprises are generally dealing with engineering, most of them will produce concrete additives, adhesives, jointing agents, plastering mortar and other supporting materials.
do-it-yourself
If you do it yourself, just follow the above steps. The putty powder must read the instructions and be mixed with water or glue in proportion, as well as cement paint.