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ASC SM Silicone Mastic High Solids Sealing and Patching Compound, White, 1 Gallon Pail
Regular price $80.75Orders start at $399 — combine any items to reach the minimum. Learn more
ASC SM Silicone Mastic High Solids Sealing and Patching Compound, White, 1 Gallon Pail
ASC SM Silicone Mastic is a solvent free, single component, high solids sealing and patching compound sold as a 1 gallon pail in white. It forms a durable, weather resistant seal on penetrations, skylights, seams, holes, cracks and detail areas on most surfaces. Apply with a brush or trowel, with polyester fabric for three-course details.
Key Features:
- High solids: 99% solids by volume per ASTM D-2369 with solvent-free, single component formulation.
- Weather resistant: Superior adhesion and flexibility withstands extreme elongation and resists weather.
- UV stable: Highly reflective, UV stable design withstands direct exposure to sunlight.
- Detail sealing: Especially developed to seal cracks, detail areas and surface imperfections.
- Versatile repairs: Seals penetrations, skylights, seams and holes, and trowels over cracks in concrete, masonry, and wood.
- Low VOC: VOC/VOS below 50 grams per liter.
- Brush or trowel: Applied in the Three Course Installation Method using a paintbrush or trowel.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | ASC |
| Manufacturer model | ASCSM1 |
| Sell unit | 1 pail, 1 gal |
| Product type | Silicone mastic, sealing and patching compound |
| Chemistry / base | Silicone, solvent free, single component |
| Color | White |
| Container size | 1 gallon pail |
| Application method | Roll, brush, or trowel |
| Dry / cure time | Tack-free 1-2 hrs; dry to handle 3-4 hrs; varies with temperature and humidity |
| Solids content | 99% by volume (ASTM D-2369) |
| VOC | <50 g/L |
| Specific gravity | 1.26 |
| Flash point | 141°F |
| Coverage / film thickness | Apply 1/8-1/4 in. (3.2-6.4 mm) per coat in Three Course Installation Method |
| Compatible substrates | Most surfaces; concrete, masonry, and wood cracks; new and existing roofs |
| Intended use | Roof repairs, priming and sealing penetrations, skylights, seams, holes and detail areas |
| Storage | Do not store below 50°F (10°C) or above 120°F (49°C); do not allow to freeze |
| Manufacturer warranty summary | One-year warranty against manufacturing defects; no labor or installation cost coverage |
| Product weight, complete sell unit | 12 lb |
Coverage & How Much You Need:
Apply at 1/8-1/4 in. (3.2-6.4 mm) per coat in the Three Course Installation Method. Additional applications may be necessary as elastic cement shrinks through drying; a 1 gallon pail suits crack, seam and detail repairs rather than large-area coating.
Fit and Compatibility:
Pairs with ASC polyester fabric in the Three Course Installation Method for reinforced detail sealing. Surfaces must be clean and dry before application; rusted metal should be brushed clean. Sold in the ASC roof repair system alongside ASC coatings and mastics.
Frequently Asked Questions (FAQ):
Q: What is included in the sell unit?
A: One 1 gallon pail of ASC SM Silicone Mastic in White.
Q: What can it seal?
A: It primes and seals penetrations, skylights, seams, holes, cracks, detail areas and surface imperfections on most surfaces.
Q: Do I need fabric with it?
A: It is applied in the Three Course Installation Method: first coat 1/8-1/4 in., embed polyester fabric while wet, then immediately apply a second layer of the same thickness.
Q: How long does it take to dry?
A: Tack-free in 1-2 hours and dry to handle in 3-4 hours, depending on temperature, humidity, and film thickness.
Q: What surface preparation is required?
A: Surfaces must be clean, dry and free of dust, dirt, oil, loose granules, mildew and contaminants; rusted metal should be cleaned with a wire brush.
Q: What is the cleanup?
A: Clean tools with soap and warm water.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Pick ASC SM for crack, seam and detail repairs on most roof surfaces where a solvent-free silicone mastic with extreme elongation is needed. Work in the morning on a warm, sunny day to maximize cure time, and do not apply when rain is expected within 24 hours. Expect shrinkage through drying, so additional applications may be needed. For flashing-grade patches without reinforcement, ASC 911 in the same family is the related option.
For exterior use only; wear protective clothing and eyewear, ensure adequate ventilation, and do not apply when heavy dew or rain is expected within 24 hours.
Order ASC SM Silicone Mastic in the 1 gallon pail for durable, weather resistant roof detail sealing.
Product Documents:
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