USG Gypsum Plaster Retarders are additives that lengthen the setting time of gypsum plaster by slowing the chemical crystal formation that causes the gypsum plaster to set or harden.

USG offers two retarder products to meet a wide range of needs

• USG Gypsum Plaster Retarder: Standard Strength is recommended for slight to moderate (30 to 45 minutes) lengthening of set times of veneer and conventional plasters as well as setting-type joint compounds
• USG Gypsum Plaster Retarder: For Lime-Based Products is used with USG Diamond® Veneer Finish, USG Red Top® Brand Finish Plaster and USG Red Top® Brand Gauging Plaster

Features

• Excessive additions of retarder will drastically reduce strength, thereby impairing the integrity of the finish work.
• Excessive amounts may produce “dry-out”—the inability of plaster to set before the water necessary for chemical reaction evaporates.
• USG Gypsum Plaster Retarders should never be added directly to the plaster mix. The addition of dry retarder does not provide controlled dispersion as quickly or uniformly as retarder premixed with water.

2.5 lb bag