Best Adhesive for Undermount Sink to Granite: 6 Picks

If you want to secure an under-mount sink to your granite countertop, you’ve probably realized finding the right adhesive can make a huge difference. However, let me inform you not all adhesives are created equal, and it can be overwhelming to find the perfect fit for your project.

When choosing an adhesive to attach an under-mount sink to granite, consider the type of adhesive suitable for granite. Ensure that the adhesive is waterproof and heat-resistant to withstand the conditions in the kitchen. Also, long-term durability is a crucial factor to keep in mind when making your selection.

To make things easier for you, I’ve researched and reviewed my top 6 choices for you to pick the best one. So, let’s explore these adhesives and discover which is best for your kitchen sink.

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6 Best Adhesives for Attaching Undermount Sinks to Granite Countertops

You don’t want to compromise your kitchen sink’s stability by using an unsuitable adhesive for granite. That’s why consider one of the adhesives I’ve listed below according to your needs:

1. Loctite 2.7-ounce clear silicone waterproof sealant
2. Gorilla 2.5-ounce max strength clear construction adhesive
3. Permatex 3-oz clear RTV silicone adhesive sealant
4. 3M marine grade 3-oz silicone adhesive sealant
5. GE household 2.8-oz silicone clear adhesive
6. BAZIC 3.38-oz waterproof silicone glue

1. Loctite 2.7-ounce Clear Silicone Waterproof Sealant

If you want a reliable and versatile adhesive for attaching your under-mount sinks to granite countertops, the Loctite clear silicone waterproof sealant offers a waterproof, long-lasting solution. This clear silicone sealant can attach an undermount sink to a granite countertop or repair a leak.

From my perspective, this clear silicone waterproof sealant is a versatile option that can bond with a wide range of materials. This adhesive can create a strong and durable bond that withstands water exposure and temperature changes, whether metal, glass, rubber, tile, or porcelain.

According to my analysis, this waterproof sealant is a trustworthy adhesive that delivers proven results. It demonstrates trusted performance by bonding and repairing saltwater and freshwater aquariums successfully.

Moreover, it remains clear without yellowing or fading over time, which makes it a reliable choice for long-term adhesive needs. It comes in a convenient 2.7 oz tub with a smooth consistency that applies evenly and smoothly.

Pros:

• Creates a waterproof and protective seal on multiple materials
• Versatile for indoor and outdoor applications
• Resists cracking, peeling, and shrinking
• Clear color that doesn’t turn yellow or fade over time
• Comes in a handy 2.7 oz tub

Cons: 

• Not be suitable for large-scale industrial applications

2. Gorilla 2.5-Ounce Max Strength Clear Construction Adhesive

Based on my research and analysis of Gorilla Max strength adhesive, I can confidently recommend it for securing under-mount sinks to granite countertops. With its exceptional durability and waterproof properties, this product is ideal for professionals and DIY enthusiasts.

If you’re looking for a dependable adhesive, the Gorilla Max Strength Clear Construction Adhesive is one of the finest options available. With its 2X strength compared to other Gorilla products, you can trust that it will withstand tough conditions.

One of the most significant advantages of this adhesive is its clear drying feature. When used to attach an under-mount sink, it won’t detract from the overall appearance of your countertop and sink. This gives your kitchen or bathroom a professional, polished look.

No matter where you live, you need an adhesive that can withstand harsh weather conditions. This adhesive’s 100% waterproof formula makes it suitable for various outdoor projects and indoor locations with high humidity levels. You won’t have to worry about the adhesive failing due to water damage.

Pros:

• 2X stronger than other construction adhesives
• Clear drying and 100% waterproof
• Repositionable, gap-filling, and paintable
• Its paintable nature allows for easy touch-ups.

Cons:

• Strong odor upon application

3. Permatex 3-oz Clear RTV Silicone Adhesive Sealant

The Permatex RTV silicone adhesive sealant is ideal for indoor and outdoor applications. This adhesive sealant is waterproof and flexible, making it ideal for indoor and outdoor projects.

I can tell you this professional-grade, sensor-safe sealant is suitable for a wide range of materials such as glass, metal, plastics, fabric, and vinyl. Its waterproof and flexible nature makes it resistant to water, ensuring a secure and long-lasting bond.

Also, I have found it effective for sealing gaps, repairing leaks, and creating strong bonds in various applications. Once it dries, it creates a strong bond that can withstand water, weather, and vibration.

However, note that once the silicone dries in the top, it becomes a one-use product with no way to reuse it. Some customers also suggest including multiple tips for multiple uses and a scraper for cleaning the nozzle.

Pros:

• 3-oz clear RTV sealant for wide application
• Waterproof and flexible for various materials and environments
• Effective for sealing gaps, repairing leaks
• Resistant to water, weather, and vibration

Cons:

• Need to use multiple tips for long application
• Becomes a one-use product

4. 3M Marine Grade 3-Oz Silicone Sealant

The 3M sealant is an effective and reliable product for attaching under-mount kitchen sinks to granite countertops. This clear sealant is specifically formulated for marine use and is suitable for sink mounting tasks.

When attaching under-mount sinks to granite countertops, I can assure you 3M marine-grade silicone sealant provides a reliable bonding performance. Whether you are a seasoned DIY enthusiast or a professional, this clear sealant is easy to apply and assures a strong, waterproof bond.

This sealant suits granite, metal, glass, paint, fiberglass, plastics, and abraded rubbers. Its versatile nature makes it popular for marine and non-marine applications.

It can be used to bond and seal surfaces both above and below the waterline. As far as I can tell, this clear sealant is formulated to withstand the harsh effects of saltwater and sunlight, making it suitable for boats, yachts, and other marine applications.

Pros:

• Versatile bonding and sealing capacities
• Marine-grade durability
• Endurance in harsh marine environments
• Easy-to-use application straight from the container

Cons:

• Difficulties with quantity and dispensing

5. GE Household 2.8-Oz Silicone Clear Glue

For attaching under-mount sinks to granite countertops, the GE silicone glue offers a strong, flexible adhesive that is reliable and waterproof. According to my analysis, the GE silicone glue offers a permanent bond.

This 100% silicone adhesive provides a permanently waterproof and flexible bond, ensuring a secure attachment. It adheres well to various materials, including glass, metal, plastic, rubber, ceramic, and painted surfaces.

The clear and low-odor formula suits household and craft applications. This adhesive also dries quickly and remains clear, making it ideal for projects where aesthetics are essential.

Pros:

• Permanently waterproof and flexible bond
• Adheres well to granite materials
• Clear and low odor formula
• Suitable for various household and craft applications

Cons:

• Hardening of the adhesive inside the tube between uses

6. BAZIC 3.38-Oz Waterproof Silicone Glue

For reliable and quick repairs, consider BAZIC silicone glue for attaching undermount sinks to granite countertops. This waterproof and crack-resistant glue sets as fast as 1 hour, providing a reliable seal around water-exposed areas.

The BAZIC waterproof glue is an excellent adhesive for mounting kitchen sink, repairing pipes, sealing gaps, and replacing fixtures. According to my analysis, this waterproof and crack-resistant glue sets fast and provides a reliable bond around water-exposed areas.

From my perspective, one of the most impressive features of this silicone glue is how it can be used indoors and outdoors. Its strong binding properties make it ideal for home improvement and craftwork.

This silicone glue dries fast, within just one hour, and remains usable in a tube. I strongly sense that this glue is perfect for fixing kitchen sink leaks and cracks.

Pros:

• Provides a reliable seal around water-exposed areas
• Suitable for repairing leaks and cracks
• Features a waterproof and crack-resistant formula
• Strong binding properties make it great for DIY

Cons:

• Not suitable for fabric repairs

Comparison Table for the Best Granite Undermount Kitchen Sink Adhesives

Product	Loctite	Gorilla Max Strength	Permatex	3M	GE	BAZIC
Size	2.7 oz	2.5 oz	3 oz	3 oz	2.8 oz	3.38 oz
Strength	Resists cracking and shrinking	2X high strength	Flexible and professional-grade	Durable and flexible bond	Permanent and flexible bond	Crack-resistant
Odor	N/A	N/A	Low odor formula	N/A	Low odor formula	N/A
Item Form	Solid	Foam	One-use product	Solid	Solid	Liquid

Factors to Consider When Choosing an Adhesive for Undermount Sink to Granite

When buying an adhesive for securing an under-mount sink to your granite countertop, I recommend considering the following factors:

Adhesive Types for Granite

When choosing an adhesive for attaching an under-mount sink to a granite countertop, consider material compatibility, waterproof sealing and curing time.

For granite, opt for adhesives specifically designed for stone applications, ensuring compatibility and a strong bond. Look for adhesives that offer a waterproof and flexible seal, especially for under-mount sink installations where water exposure is frequent.

Consider the curing time and resistance to water, weather, and vibration to ensure long-lasting performance in a kitchen or bathroom environment. Additionally, evaluate the adhesive’s versatility for bonding various materials and its suitability for indoor and outdoor use.

Sink Material Compatibility

To ensure a secure bond between the granite countertop and the undermount sink, consider the adhesive’s compatibility with the sink material. This includes granite, stainless steel, porcelain, or composite materials. It’s crucial to ensure that the adhesive is suitable for use with the undermount sink material.

Take into account any specific characteristics or finishes of the sink material. Verify that the adhesive is designed to bond effectively with the sink material for long-lasting and durable results.

Additionally, check if the adhesive won’t cause damage, discoloration, or other adverse effects on the sink material. Consider any special requirements for the specific type of sink material used with the adhesive. This will ensure a successful and lasting attachment between the sink and the granite countertop.

Waterproof and Heat-Resistant

Ensure a secure bond between the undermount sink and the granite countertop by selecting a waterproof and heat-resistant adhesive.

A waterproof adhesive ensures a strong seal unaffected by water exposure, ideal for high-moisture environments like kitchens and bathrooms. Additionally, a heat-resistant adhesive can withstand high temperatures without degrading or losing its bond, making it suitable for areas near stovetops or ovens.

Choosing an adhesive with these properties provides long-lasting durability, especially when moisture and heat are present.

Application Ease

Consider the ease of application when choosing an adhesive for attaching an undermount sink to a granite countertop. Look for repositionable adhesives that are easy to work with, allowing for adjustments before the final bonding occurs.

The consistency of the adhesive is crucial as a smooth and uniform texture can make application easier and more precise. Additionally, I suggest evaluating the adhesive’s drying time, as quicker drying adhesives may offer the advantage of faster project completion.

Check for specific application instructions the manufacturer provides to ensure smooth and hassle-free application. Considering these factors, you can ensure that the adhesive chosen for attaching the undermount sink to the granite countertop is easy to work with and facilitates a seamless installation process.

Long-Term Durability

For lasting security in attaching an undermount sink to granite, prioritize an adhesive with proven resistance to water, temperature changes, and heavy loads. Long-term durability is crucial for maintaining a strong and secure bond over time.

Look for adhesives specifically designed to withstand environmental conditions and constant use without deteriorating. Seek out products that emphasize long-lasting or permanent bonds to ensure the sink remains securely attached to the granite countertop for an extended period.

Additionally, assess the adhesive’s resistance to chemicals, stains, and cleaning agents commonly used in kitchen environments to ensure its long-term effectiveness.

How do you adhesive an undermount sink to granite?

Before you start installing the undermounted sink, make sure it fits properly. You can dry-fit the sink over the hole in your granite countertop to determine if any adjustment needs to be made. Once you’ve confirmed that the sink is the correct size, take it out and clean the underside of the countertop and the sink.

After this, you’ll want to apply a thick bead of silicone sealant around the edge of the sink using an adhesive gun. The bead should be thick enough to create a strong bond between the sink and the countertop, but not so thick. 

Ensure the adhesive has dried according to the manufacturer’s instructions before proceeding. This step is crucial as it allows the sealant to set and create a strong connection.

Finally, you can mount the sink into the hole in the granite, double-check its position, and proceed with any additional faucets and drains you may need to install.

What kind of adhesive should I use for an undermount sink?

You can use a construction adhesive ideal for gluing the sink clip studs in place. It’s best to use the silicone-based adhesive recommended by the sink manufacturer.

Aside from this, using a caulking gun, you’ll need to apply a thick bead of silicone adhesive along the inner edge of the outline. The silicone adhesive should be specially formulated for use with granite and can hold up well under exposure to moisture.

Is epoxy or silicone better for under mount sinks?

When securing undermount sinks, you can consider choosing between epoxy and silicone.

Epoxy is known for its strength and durability, an ideal choice for securing under-mount sinks. It is a two-part adhesive that hardens quickly and can withstand extreme temperatures and moisture. Epoxy can be used to attach the sink to the countertop, forming a bond that is nearly impossible to break.

Meanwhile, silicone is more flexible and easier to apply than epoxy. It is a sealant that keeps water and moisture from seeping into the space between the sink and the countertop. Silicone is also resistant to mold and mildew, making it an excellent choice for wet areas like kitchens and bathrooms.

Ultimately, the choice between epoxy and silicone depends on your specific needs. If you want a strong and permanent bond, epoxy is the way. However, silicone is your best bet if you’re looking for a flexible and mold-resistant option.

How long does it take for silicone to dry under the kitchen sink?

Once you’ve applied the silicone to seal your undermount sink, it may take 12 to 24 hours to completely dry and cure the adhesive. However, the time it takes for the silicone to dry can vary depending on a few factors.

• Firstly, it depends on the specific product you’re using. Most silicone sealants have instructions for the recommended drying time, typically between 12-24 hours.
• Secondly, the temperature and humidity in the room can affect the drying time. If it’s a warm and dry day, the silicone may dry faster than if it’s cold and humid.
• Lastly, the amount of silicone used can also affect the drying time. If too much silicone is applied, it will take longer to dry and set. It’s best to apply a thin and even silicone layer to ensure a speedy drying time.

Choose the Right Adhesive to Get a Strong and Secure Bond

Proper selection and application of the adhesive are crucial to ensure a strong and secure bond between your granite countertop and under-mount sink. In this article, I have discussed the important factors for selecting an adhesive suitable for granite, waterproof, heat-resistant, and durable over time.

Following these guidelines and selecting the right adhesive for your project, you can enjoy a beautiful, functional under-mount sink installation for years. While all the adhesives mentioned above are great for bonding, the Loctite clear silicone sealant is the best.

This clear silicone sealant is suitable for attaching an under-mountable sink to a granite countertop or repairing a leak. So, if you want a trustworthy and versatile adhesive, do not forget to purchase one.

Last update on 2024-04-28 / Affiliate links / Images from Amazon Product Advertising API