Calcined Hemihydrate Gypsum Powder for Wall Coating

When the calcined hemihdrate gypsum powder is used for walling coating, it's important to figure out for undercoating or the final coating sincere there is a big difference between the quality of gypsum powder for these 2 kinds of wall coating.

In order to identify the 2 kinds of gypsum powder, we call the undercoat plaster Alabaster Gypsum Powder, and call the final coat plaster Alpha Gypsum Powder or Superior Wall Coating Gypsum Powder.

Main Difference:
1, Classification
>Undercoat gypsum plaster, bending plaster
>Final gypsum plaster, finish plaster

2, Application
>Undercoat/bending plaster is directly used on bare wall surface of

• Clay(Red) brick masonry
• Fly ash brick masonry
• Concrete brick masonry
• Cellular Lightweight Concrete Blocks(Siphorex) Masonry
• Auto claved Aerated Concrete Blocks(Ecolite) Masonry

>Final/finish plaster is directly used

• on ceiling up to thickness of 3~8mm
• as final finishing coat on undercoat wall plaster

3, Standard Consistency
>Undercoat plaster consistency is mostly around 70%
>Final plaster is around 77~80%

4, Initial Setting Time
>Undercoat plaster is 6~8 minutes
>Final plaster is 6~9 minutes

5, Compressive Strength
>Undercoat plaster is 66.4kg/Sq.m
>Final coat plaster is 60kg/Sq.m

6, Coverage
>Undercoat plaster is 80~85/Sq.m in 13mm per MT
>Final coat plaster is 290/Sq.m per MT

7, Color
>Undercoat plaster is brownish white
>Final coat plaster is pure white

8, Fineness
>Undercoat plaster is 120 mesh
>Final coat plaster is 160 mesh