Raiva International Trading Group (RAIVACO) logo

Gypsum Plaster Supplier & Exporter — 100 and 200 Mesh Stucco

CaSO₄·½H₂O Calcined Plaster · CaSO₄ > 90%

Calcined gypsum plaster in a 100 mesh base coat and a 200 mesh super-micronized finish grade, produced to international standards and tested to BS EN 13279-2 and ASTM C471-M-20 for setting time, compressive and flexural strength, slump and whiteness. Supplied in 25 kg bags with a batch-specific Certificate of Analysis.

Gypsum plaster powder (stucco, calcium sulfate hemihydrate) 200 mesh super micronized — B2B bulk export supplier Raivaco Whiteness up to 95.5%

Supply capability at a glance

95.5%

Whiteness, 200 mesh grade

7.5 N/mm²

Compressive strength at 2 h

6–12 min

Initial setting time

Per batch

Certificate of Analysis

Physical Properties

Formula

CaSO₄·½H₂O

Purity

> 90% CaSO₄

Whiteness

88 – 95.5%

pH

7.2 – 7.3

Water / Stucco

75 – 83%

Packing

25 kg bag

Synonyms: Stucco, Calcined Gypsum, Plaster of Paris, Building Plaster, Gypsum Powder · White, smooth, free-flowing powder derived by heating gypsum rock.

Grades & Chemical Analysis

Two plaster grades — the 100 mesh base coat for body and build, the 200 mesh super-micronized grade for a flat, polished finish coat and for board plants. Select a grade to view its full analysis.

Base Coat — Body and build

100 Mesh Gypsum Plaster

CaSO₄ 94%
CaSO₄
94% (spec > 90)
Whiteness
88% (spec 88 up)
Initial Setting Time
7 min (spec 5–12)
Final Setting Time
15 min (spec 11–25)
Compressive Strength, 2 h
6.21 N/mm² (spec ≥ 6)
Flexural Strength, 2 h
2.50 N/mm² (spec ≥ 2)
Water / Stucco Ratio
75%
Slump
210 mm (spec 155–230)
Retained on 100 mesh sieve
8%
Combined Water
5.0% (spec 4–7)

pH 7.2–7.3 on both grades (spec 7–10). Test methods: BS EN 13279-2 for setting time, strength, slump and water/stucco ratio; ASTM C471-M-20 for CaSO₄ and combined water; whiteness meter WSB-2A. Values are typical batch results against the stated acceptance limits.

200 Mesh Grade — Full Oxide Analysis

The complete chemical breakdown behind the super-micronized grade — the low iron and silica figures are what keep the finished plaster bright.

Full oxide analysis of 200 mesh super micronized gypsum plaster
ComponentResult
CaSO₄·2H₂O96.85%
SO₃47.98%
CaO31.53%
Combined Water20.15%
SiO₂0.11%
Al₂O₃0.08%
Fe₂O₃0.07%
MgO0.06%
Free Water0.02%

Analysis to ASTM C471-M-20.

Bespoke Production

Need a different mesh or setting time?

Setting time, water demand, mesh and whiteness can all be adjusted in production, and retarded or accelerated formulations are available. Send us your target specification and we will confirm feasibility, pricing and lead time.

Applications

Gypsum plaster is fire-resistant, dimensionally stable and does not shrink as it sets — which is why it has outlasted every material proposed to replace it.

Wall & Ceiling Plastering

Base coat and polished finish coat for interior surfaces.

Gypsum Board Manufacture

Core material for plasterboard and drywall lines.

Prefabricated Gypsum Walls

Cast panels for partition wall systems.

Decorative Mouldings

Cornices, ceiling roses and architectural ornament.

Sculpture & Artistic Casting

Fine detail casting where surface finish matters.

Ceramic & Sanitaryware Moulds

Absorbent slip-casting moulds.

Fire-Resistant Linings

Passive fire protection through the chemically bound water.

Dental & Medical Casts

Impression and model materials.

Self-Levelling Screeds

Floor levelling compounds and jointing plasters.

Packaging, Logistics & Trading Terms

How we bag, certify and ship gypsum plaster. Terms can be adapted by agreement — tell us what your operation needs.

Minimum Order Quantity
1 × 20 ft container (approx. 25 MT) bagged. Trial quantities available for qualification before a full order.
Packaging
25 kg 3-ply laminated PP bags, palletized and shrink-wrapped. Jumbo bags and bulk tanker loading available for board plants. Moisture-proof PE lining on request.
Incoterms & Loading Ports
EXW, FOB, CFR and CIF (Incoterms® 2020). Standard loading at Bandar Abbas and Bandar Imam Khomeini; other ports by arrangement.
Quality Certification
Batch-specific CoA with every shipment covering whiteness, setting times, compressive and flexural strength, slump, sieve residue, combined water, pH and CaSO₄, tested to BS EN 13279-2 and ASTM C471-M-20.
Lead Time
7–14 days for standard grades after order confirmation; 15–25 days for custom-milled or specially packed material.
Storage & Handling
Store in a dry, covered area, bags sealed and off the ground. Calcined plaster re-absorbs atmospheric moisture, which slowly reverts the hemihydrate to dihydrate and lengthens setting time. Use within 3 months of production for consistent set behaviour.

Certificate of Analysis

A batch-specific CoA is issued with every shipment. Third-party inspection by SGS, Bureau Veritas or an inspector of your choice can be arranged at the buyer’s cost.

Ready to quote

Send us your grade, tonnage, destination port and packaging and we will return a firm FOB/CFR/CIF price with lead time.

Request a Gypsum Plaster Quote

Gypsum Plaster — Frequently Asked Questions

What is the difference between the 100 mesh and 200 mesh grades?
Fineness, and what that does to the finished surface. The 100 mesh grade is a base coat — coarser, lower water demand at 75% water/stucco, and it builds thickness. The 200 mesh super-micronized grade leaves only 0.2% on a 200 mesh sieve, which is what allows a flat, polished final layer; it also runs higher whiteness at 95.5% and higher compressive strength at 7.5 N/mm².
Which standards is the plaster tested to?
BS EN 13279-2 for initial and final setting time, compressive and flexural strength at 2 hours, slump and water/stucco ratio; ASTM C471-M-20 for CaSO₄ content, combined water and sieve residue; whiteness by WSB-2A whiteness meter. Every figure on the certificate carries its test method.
What setting time should I expect?
Initial set 6–12 minutes and final set 12–25 minutes on the standard grades, with typical batch results of 7 minutes initial and 15–16 minutes final. That window gives enough working time to apply and level before the plaster locks up. Retarded formulations for longer open time are available on request.
Why does whiteness matter in plaster?
Because it decides how many coats of paint you need. A plaster at 95.5% whiteness takes colour evenly and hides with a single topcoat; a duller plaster shows through and pushes the painter to a second or third coat. It also matters for gypsum board face quality and for any decorative casting that will be left unpainted.
How should gypsum plaster be stored, and what is the shelf life?
Dry and covered, bags sealed and off the ground. Calcined plaster re-absorbs moisture from the air, which reverts hemihydrate back towards dihydrate and progressively lengthens setting time and weakens the set. For consistent behaviour use within about 3 months of production; for humid destinations we recommend moisture-proof PE-lined bags.
Can you supply the raw gypsum rock instead?
Yes. If you calcine on site, see our raw gypsum grades — from 88% cement grade up to 99% premium white, supplied as 0–50 mm lump in bulk or jumbo bags.

Related Products