Dowsil 791 External Weatherproofing Silicone Sealant 600ml - Black

DOWSIL™ 791 Weatherproofing Silicone Sealant is a one-part, low modulus, neutral curing sealant designed for both commercial and domestic applications. It offers exceptional weatherproofing properties and provides excellent adhesion to most porous and non-porous surfaces without the need for a primer. Ideal for general glazing and weather sealing in curtain walls and building facades, this versatile sealant is resistant to ozone, UV radiation, and extreme temperatures, ensuring long-lasting durability and protection.

• Superior Weather Resistance
• Flexible and Durable
• Adheres to a wide range of substrates

Before applying the sealant, ensure that all surfaces to be sealed are clean, dry, sound, and free from grease, dust, or any other contaminants that could affect adhesion.

• For non-porous surfaces (such as glass, aluminum, or PVC), clean them using DOWSIL™ R-40 Universal Cleaner. Apply the cleaner to a clean, lint-free cloth and wipe the surface thoroughly. After cleaning, make sure the surface is completely dry.
• For porous surfaces (such as concrete, brickwork, or mortar), mechanically clean the surface to remove any loose particles or debris. Use tools like a steel brush, sanding disc, or similar methods to ensure a smooth, clean surface.
• After cleaning, check that the surfaces are completely dry and free of any contaminants to ensure proper adhesion of the sealant.

We recommend using the Geocel ecoSEAL Cartridge with the Dowsil 791 External Weatherproofing Silicone Sealant Sausage.

• Begin by installing any necessary backing materials, joint fillers, setting blocks, spacer shims, or tapes to prepare the joint. These materials help ensure proper sealant application and provide back pressure to prevent three-sided adhesion.
• Mask the areas adjacent to the joint to ensure neat, straight sealant lines and to protect surrounding surfaces from excess sealant.
• Primer is generally not required for non-porous surfaces. However, for certain porous surfaces, a primer may be necessary to achieve optimal adhesion. Conduct a test placement on a small area to confirm compatibility.
• Apply DOWSIL™ 791 Silicone Weatherproofing Sealant in a continuous bead using positive pressure. The sealant can be applied with a variety of air-operated guns or bulk dispensing equipment such as the Geocel Cox Skeleton Gun.
• Before a skin forms (typically within 15 minutes), use light pressure to tool the sealant for best results we recommend using Bedec Silicone Profilers. Spread it evenly against the backing material and the joint surfaces to ensure a strong bond.
• As soon as the sealant has been tooled, immediately remove the masking tape for a clean, neat finish.

Always follow manufacturers instructions found on the cartridge.

Q. How does DOWSIL™ 791 cure?

A. The sealant cures by reacting with moisture in the air, transforming into a flexible and durable silicone rubber seal. The curing process occurs at ambient temperatures.

Q. Can DOWSIL™ 791 be used on all types of surfaces?

A. Yes, DOWSIL™ 791 is designed to bond well with a wide range of materials, including glass, metal, ceramics, PVC, and painted surfaces. It is ideal for weatherproofing joints around windows, doors, and other exterior applications.

Delivery

All orders placed on a working day before 3pm will be dispatched on the same day for next working day delivery. Orders placed before 3pm on Friday will be delivered on Monday (excluding bank holidays). Orders placed on weekends and Bank Holidays will be dispatched on the next working day. All orders have a charge of £3.99 for express delivery. We strongly suggest customers avoid booking tradespeople until they receive their order. Next Day Paint will not be held liable for any costs incurred due to order processing errors, delivery delays, or other issues that may result in financial loss.

Special Delivery

You can now choose some special delivery options. 

• AM Delivery: Get your order by 2pm
  If placed on a working day before 3pm, the AM Delivery will be dispatched on the same day for Next Working Day delivery. 
  Orders placed before 3pm on Friday will be delivered on Monday AM (excluding bank holidays). Orders placed on weekends and Bank Holidays will be dispatched on the next working day for delivery on the following AM. All orders have a charge of £12.99 for AM delivery.

• Late Cut-Off: Get an extra hour to place your order for Next Working Day delivery.
  Orders placed on a working day before 4pm will be dispatched on the same day for Next Working Day delivery. 
  Orders placed before 4pm on Friday will be delivered on Monday (excluding bank holidays). Orders placed on weekends and Bank Holidays will be dispatched on the next working day. All orders have a charge of £5.99 for Late Cut-Off delivery.

• Saturday Delivery: Get your order on Saturday
  Option available on Fridays. Orders placed on Friday before 3pm will be delivered on Saturday. All orders have a charge of £9.95 for Saturday delivery.

Exceptions

We do not deliver to the Channel Islands or the Republic of Ireland

Certain postcodes delivery times and charges may vary please head to the cart to see your available delivery options.

Returns

We offer a 14 day money back guarantee for all goods shipped correctly that are not required. If the item is not required, please send the item back for a full refund in its original condition, unused with its original packaging. Please note return for unwanted item is at your own expense.

Contact us as soon as possible to inform us you will be returning the product either by the contact form below or by calling our team on 0161 960 0217.

Please note that all tinted paint purchases are final and non-refundable, if you are unsure this is your product please check the listing or contact us for details. Once an order is processed and mixed, it cannot be returned or refunded, even in cases of delivery delays or changes in circumstances.

While we strive to meet delivery timelines, we are not responsible for any delays once the product has been shipped. Delivery times may vary due to factors such as courier delays, weather conditions, or other circumstances beyond our control.

We always recommend getting samples or contacting us for free of charge colourcharts. We do our best to represent colours as accurately as possible however screens variations and different surfaces can alter this. Unfortunately in the event you do not like the colour we are unable to accept the product back if they it has been opened.

Damaged Paint

Please visit our damages page where we can help resolve the issue for you. 

Incorrect Item

We will be happy to organise an exchange for the correct goods at no extra charge to yourself, please get in touch to organise this.

Faulty Items

If you find a fault with your product, we can offer a full refund or exchange within 30 days. We test every product that is returned to us, sadly if a product is found to have no fault we cannot refund this and the you will be given the option to have this returned to you. Please get in touch to discuss these options. If you find fault after 30 days of purchase you may wish to contact the manufacturer directly as they will be able to offer support with the product.