Short Answer: Mastic powder is a type of lightweight polymer construction gypsum. After joint filling and before painting, a thin layer is applied to the wall to achieve a completely smooth surface. Its main application is preparing walls for paint and wallpaper, and working on gypsum boards, gypsum-faced panels, gypsum tiles, and plasterwork. Mastic Powder Sahar is available in 5 kg bags.

What is Mastic Powder?

Mastic powder belongs to the family of polymer gypsum. This means its base is gypsum, and polymer additives have modified its behavior, making it suitable for delicate work and thin layers. For deeper joints and cracks, joint filler putty is designed. The role of mastic is to finalize the surface, just before painting or wallpapering.

The technical specifications of Sahar mastic powder, according to the product specification sheet:

| Feature | Value |

|---|---|
| Initial Setting | None |
| Final Setting | 120 minutes |
| Particle Size | 200 |
| Whiteness | 87 to 88 percent |
| Gypsum Water | 60 to 100 grams |
| Weight per Bag | 5 kg |

A particle size of 200 means the powder is very fine and provides a smooth surface. The final setting time of 120 minutes also allows enough time for applying and smoothing the thin layer.

Applications of Mastic Powder

Creating a smooth and even surface before painting the building

Preparing walls for wallpaper installation

Working on gypsum boards and gypsum-faced panels

Working on gypsum tiles and plasterwork

Difference Between Mastic Powder and Painting Putty and Joint Filler

All three products are lightweight polymer gypsum and are available in 5 kg bags, but each is designed for a specific stage of work:

| Product | Main Application | Particle Size | Final Setting |

|---|---|---|---|
| Joint Filler Putty | Filling deeper joints and cracks, correcting overall joints of drywall and plasterwork, repairing serious damage | 160 | 90 minutes |
| Painting Putty | Filling hairline cracks, covering nail holes, screws, and anchors, priming before painting | 200 | 120 minutes |
| Mastic Powder | Final thin layer after joint filling and before painting, working on gypsum boards, gypsum tiles, and plasterwork | 200 | 120 minutes |

In simple terms, the usual order of work is: first, deeper joints and cracks are filled with joint filler, then hairline cracks and nail holes are filled with painting putty, and finally, a thin layer of mastic prepares the surface for paint or wallpaper.

How to Use Mastic Powder

Surface Preparation: The working surface must be clean and dry.

Mixing: Mix mastic powder with water.

Resting the Mixture: Wait for 2 to 3 minutes.

Stirring: Stir the mixture until it becomes uniform.

Application: Apply a thin layer (thin film) on the surface.

How to Use Painting Putty

The working surface must be clean, dry, and free of dust.

Mix the powder with a ratio of 60 grams of water to 100 grams of powder.

Fill the joints, cracks, and holes.

Finally, apply a thin layer of putty on the surface.

Buying Mastic Powder and Putty Directly from the Factory

You can buy mastic powder, painting putty, and joint filler directly from the Gach Sahar factory in Semnan. The minimum order from the factory is 10 tons. The current price of each product is available on the product page in the store. For ordering and coordinating delivery, contact the sales department. To learn about other products from the factory, see the Comprehensive Guide to Semnan Gypsum.