top of page

sg mastic
2-component epoxy

seal Secure protect


SG Mastic differentiates itself from all other epoxy systems with its exceptionally low pinhole formation rate (< 1%) and bonding capacity. A 2-component, solvent-free, moisture insensitive epoxy system, SG Mastic’s 100% solid, low-odor amine-cured proprietary formula provides exceptional resistance to most organic and inorganic acids. Specifically designed for the protection of sanitary manholes, wet wells, and valve vaults, it cures in the presence of moisture. Formulated to be mixed on site without the need for proprietary equipment, its paste-like viscosity is designed to withstand sagging at thicknesses up to ¼ inch. SG Mastic is recommended for coating horizontal, vertical, and overhead surfaces.

typical uses

SG Mastic provides a non-structural seal over CMS 10K cementitious mortar to protect the underlying structure from exposure to destructive gasses prevalent in manholes, lift stations, valve vaults, or other sewer treatment environments. 

environmental limitations

Apply only in good weather, when air and surface temperatures are above 50°F and surface temperature is at least 5° above wet bulb temperature reading. For optimum application, bring product to between 70° and 90°F and maintain in heated storage prior to mixing and application. Exposing SG Mastic to dew or rain while uncured may impair the curing process as well as the adhesion of subsequent coats. 

surface preparation

Concrete surfaces must be clean, dry, properly cured and free from curing compounds, oil, grease, dirt, chemical contaminants, waxes, as well as previously applied coatings which are incompatible with SG Mastic. Brush or water blast to provide an etched surface and to remove contaminants and latents. Remove dust before coating. Apply SG Mastic as specified.


Mix only complete units. The A Component container is short filled to allow addition of B Component. Add B Component to A Component container and thoroughly blend with jiffy mixer for two to three minutes. Allow to stand a minimum of five minutes prior to application. DO NOT THIN the mixture. Usable life of mixed material is a function of material temperature. 


Apply to required thickness using gloved hand or spatula (125 mils recommended). After material has achieved an initial set (approximately 30 to 40 minutes), using a clean glove, dip gloved hand in recommended solvent. Solvent applied via glove will level previously applied SG Mastic to desired smoothness. Keep glove constantly wet with solvent. Solvent on surface will evaporate quickly. Where two coats of SG Mastic are required to achieve the required film thickness, the interval between coats should be as short as possible. To insure maximum inter-coat adhesion, it is recommended that: (1) the next coat be applied as soon as possible, after the previous coat is firm, and (2) if the previous coat has cured beyond the maximum recoat time given in Drying Time section above, uniformly abrade the surface by brush blasting or mechanical grinding to provide an adequate mechanical bond before recoating.


Following application of the final coat, see Curing Properties above for detailed information on recommended cure time. Cure times are proportionately shorter at elevated temperatures and longer at lower temperatures. For immersion service, curing time is 12 hours at 77°F or higher. 

clean up

Clean all equipment immediately after use with Rainstopper #5 Cleaner or xylene.

continuity testing

SG Mastic shall be tested for holidays at the specified voltage using a holiday detector to verify continuity of fully cured film. A suitable device is the Tinker-Rasor Model M-1. Consult equipment manufactures voltage-per-mil-thickness of applied coating recommendation. Holiday areas should be sanded or brush-blasted, then recoated over abraded areas only. 


KEEP OUT OF REACH OF CHILDREN. Take these precautions during application and before coating dries. Avoid breathing of vapor or spray mist. Avoid contact with eyes and skin. Use a barrier cream on exposed skin. Wash thoroughly after handling. In case of spillage, absorb and dispose of in accordance with local applicable regulations. Do not take internally. Use with adequate ventilation during application and drying. In tanks and other confined areas, use only with adequate forced air ventilation to prevent dangerous concentrations of vapors which could cause death from explosion or inhalation. Use fresh air masks, clean protective clothing, and explosion-proof equipment. Follow OSHA regulations regarding ventilation and respiratory equipment. Any mixture of Components A and B will inherit the associated hazards of each individual component. Contact Rainstopper to obtain Material Safety Data Sheets for complete information on safety and handling.

first aid

In case of skin contact, wash thoroughly with soap and water. For contact with eyes, flush immediately and continuously with water for 15 minutes and call a physician. If affected by inhaling vapor, move to fresh air. If swallowed, call a physician immediately. Do not induce vomiting.

in case of fire

Use dry chemical, foam, water fog, or CO2 to extinguish flames.


bottom of page