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Superior Bonding: DOWSIL 991 Aluminum Window Frame Silicone Sealant

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DOWSIL 991 is a premium silicone sealant specifically formulated for aluminum window frame applications. Offering exceptional adhesion and weather resistance, it stands as the preferred choice for professionals in construction and window installations. A top-tier sealant is paramount, ensuring longevity, structural integrity, and energy efficiency in every project.

Key Features of Dowsil 991 Aluminum Window Frame Silicone Sealant

DowSil 991 Aluminum Window Frame Silicone Sealant boasts a range of outstanding attributes that render it an exceptional choice for sealing aluminum window frames:

1. Exceptional Adhesion

This sealant excels in adhering to aluminum surfaces, guaranteeing a secure, long-lasting bond that effectively seals gaps and joints.

2. Superior Weather Resistance 

It offers robust resistance to adverse weather conditions, safeguarding against rain, wind, and other harsh environmental factors. This safeguard prevents water intrusion and preserves the structural integrity of the window frame.

3. Enduring Performance 

DowSil 991 is meticulously engineered for enduring performance, diminishing the necessity for frequent resealing and maintenance. It sustains its efficacy and resilience over time.

4. Flexibility

The sealant's flexibility accommodates joint movements, permitting materials to expand and contract without compromising the seal's integrity. This adaptability ensures the seal remains intact even in dynamic conditions.

5. UV and Temperature Endurance 

Specifically formulated to endure exposure to ultraviolet (UV) radiation and extreme temperatures, it resists deterioration and upholds its efficacy in various weather conditions.

Benefits of Using DOWSIL 991

Utilizing DOWSIL 991 offers a host of benefits for window installations:

1. Increased Lifespan

DOWSIL 991 extends the lifespan of window installations by providing superior weather resistance, preventing water intrusion, and maintaining the structural integrity of frames. This translates to longer-lasting windows and reduced replacement needs.

2. Reduced Maintenance Costs

With its long-lasting performance and resilience, DOWSIL 991 minimizes the need for frequent resealing and maintenance. This reduction in upkeep expenses saves both time and money.

3. Enhanced Aesthetic Appearance

DOWSIL 991 retains its original appearance over time, without yellowing or discoloration. This ensures that window frames maintain their aesthetic appeal, contributing to the overall visual appeal of buildings.

4. Energy Savings 

The improved insulation properties of DOWSIL 991 enhance the energy efficiency of windows. By sealing gaps and joints effectively, it helps prevent drafts and heat loss, leading to potential energy savings and reduced utility bills.

Application Instructions

Application Instructions for DOWSIL 991 Aluminum Window Frame Silicone Sealant:

dowsil 991 aluminum window frame silicone sealant

Surface Preparation Guidelines

  • Ensure that the surface is clean, dry, and free from dust, dirt, oil, and other contaminants.
  • If needed, use a suitable solvent to clean the surface thoroughly. Allow it to dry completely before application.
  • For optimal adhesion, roughen non-porous surfaces like glass or metal with abrasive material, and then remove dust.

How to Apply for Best Results?

  • Cut the nozzle of the sealant cartridge at a 45-degree angle to the desired bead size. Insert the cartridge into a caulking gun.
  • Apply a continuous bead of sealant to the joint or gap, ensuring full contact with both sides of the joint.
  • Tool the sealant immediately using a tool dipped in a soap and water solution to create a smooth, even finish.
  • Remove excess sealant before it cures. Clean tools and hands with a suitable solvent.

Curing Time and Conditions

  • DOWSIL 991 typically skins over in about 15-30 minutes at room temperature (77°F or 25°C) and 50% relative humidity.
  • Full cure may take up to 7 days, depending on temperature and humidity conditions. The sealant should not be exposed to water during this time.
  • Ensure proper ventilation during curing to allow acetic acid vapors to dissipate.

Tips for Ensuring Optimal Bond

  • Adhere to recommended surface preparation guidelines for the best adhesion.
  • Apply sealant in temperatures between 40°F (4°C) and 100°F (38°C) for ideal results.
  • Do not dilute the sealant or mix it with other materials.
  • Ensure a proper bond line thickness for optimal performance.
  • Avoid exposure to water or rain until the sealant is fully cured.
  • By following these application instructions, you can achieve the best results with DOWSIL 991 Aluminum Window Frame Silicone Sealant, ensuring a secure and long-lasting seal for your window frames.


Safety and Handling Guidelines for DOWSIL 991 Aluminum Window Frame Silicone Sealant

Recommended Safety Gear and Precautions

  • Wear appropriate personal protective equipment (PPE), including safety glasses and gloves, to prevent skin and eye contact.
  • Work in a well-ventilated area or use respiratory protection if working in confined spaces.
  • Avoid breathing in vapors or mists.
  • Keep the product out of reach of children and pets.
  • Read and follow the manufacturer's safety data sheet (SDS) for detailed safety information.

First Aid Measures in Case of Exposure

  • Skin Contact: Wash affected skin areas with soap and water. Remove contaminated clothing.
  • Eye Contact: Rinse eyes gently with plenty of water for at least 15 minutes while keeping eyelids open. Seek medical attention if irritation persists.
  • Inhalation: If inhaled, move to fresh air. Seek medical attention if respiratory irritation occurs.
  • Ingestion: Do not induce vomiting. Seek medical attention immediately.

Storage Recommendations

  • Store the sealant in its original, tightly closed container.
  • Keep the container in a cool, dry place away from direct sunlight and extreme temperatures.
  • Store away from incompatible materials and sources of ignition.

Disposal Guidelines

  • Dispose of unused or excess products in accordance with local, state, and federal regulations.
  • Do not pour the sealant or residues down drains or into water sources.
  • Consider recycling or contacting a hazardous waste disposal facility for proper disposal guidance.
  • Adhering to these safety and handling guidelines is crucial for the safe and responsible use of DOWSIL 991 Aluminum Window Frame Silicone Sealant. Always prioritize safety and follow recommended procedures when working with this product.

Comparison with Other Market Sealants

Why Choose DOWSIL 991 Over Competitors?

Choose DOWSIL 991 over competitors for superior adhesion to aluminum, enhanced weather resistance, long-lasting performance, flexibility, and UV/temperature resistance.

Real-world Testimonials and Case Studies.

Real-world testimonials and case studies demonstrate its reliability in preventing leaks, increasing window lifespan, and reducing maintenance costs, making it a trusted choice for sealing aluminum window frames. Users consistently report improved energy efficiency, aesthetics, and overall satisfaction when opting for DOWSIL 991, highlighting its effectiveness and durability compared to other sealants on the market.


DOWSIL 991 Aluminum Window Frame Silicone Sealant excels as the premier choice due to its outstanding bonding capabilities. With its unmatched adhesion, weather resistance, and durability, it remains the preferred option for sealing aluminum window frames, guaranteeing enduring and reliable performance in diverse environmental conditions.