Product line
Gypsum plaster retarder
Product overview
What Gypsum Retarder is
Gypsum retarder extends the working time of gypsum plaster, joint compound and anhydrite screeds. Dosage is tuned to the target open time; final hardness is preserved when the retarder is dosed within the recommended window.
Benefits
Key benefits
Extends setting time predictably at low dosage
Does not reduce final surface hardness within the dosage window
Works in hemihydrate and anhydrite systems
Applications
Typical applications
- Gypsum plaster
- Joint compound
- Anhydrite screed
- Gypsum blocks
Key facts
Gypsum Retarder at a glance
| Property | Value |
|---|---|
| CAS number | Mixture — no single CAS |
| HS code | 3824.99 |
| Appearance | White to light-brown powder |
| Pack sizes | 25 kg · 12.5 kg · 6.25 kg · 1,000 kg jumbo bag |
The HS code is the international 6-digit code; destination customs classification governs. Pack sizes are the standard range — other sizes are quoted on request.
Packaging & loading
How Gypsum Retarder ships
| Item | Detail |
|---|---|
| Pack sizes | 25 kg · 12.5 kg · 6.25 kg · 1,000 kg jumbo bag |
| 20′ FCL — loose | Loading quantity on request |
| 20′ FCL — palletised | Loading quantity on request |
| Custom printing | Available on all pack sizes; artwork design free of charge |
Loading figures are for a 20-foot container. Exact quantity depends on pallet pattern and on how the bags are stacked — we confirm it against your order. Figures marked estimated are converted from the measured bulk volume.
Part of ALCellu's 60,000 t/yr production capacity.
FAQ
Questions buyers ask about Gypsum Retarder
How does a gypsum retarder work?
A gypsum retarder extends the working time of gypsum plaster, joint compound and anhydrite screed by slowing the conversion of hemihydrate to dihydrate. Dosage is tuned to the target open time rather than picked from a table, because the same plaster from two plants can need different additions. It works in both hemihydrate and anhydrite systems.
Does a retarder reduce the final strength of the plaster?
Not within the recommended dosage window. Above it, the set is delayed so far that the crystal structure develops differently and final surface hardness drops. That is why the dosage is set against a target open time and confirmed on a trial with your own plaster, instead of being increased until the working time feels comfortable.
How is gypsum retarder packed and shipped?
Gypsum Retarder ships in 25 kg, 12.5 kg and 6.25 kg bags or 1,000 kg jumbo bags. Custom printing is available on all pack sizes and the artwork design is free of charge. The minimum order is 1 metric ton. Loading quantities for a 20-foot container are quoted per order. A free sample is available so you can run a trial mix before ordering.
Ask for the Gypsum Retarder TDS and a free sample
Tell us the system you are formulating and the standard you work to. We reply with the TDS, the pack sizes and the loading figure for your quantity.