For years, the best glue for undermount sinks lacked a truly waterproof, gap-filling solution that holds under constant moisture—until now. Having tested various adhesives, I can tell you that the Gorilla Max Strength Clear Construction Adhesive 9 oz stands out. Its specifically designed formula offers 2x the strength of typical construction glues, making it perfect for securing heavy sinks deep beneath countertops. When applied, it’s smooth and leaves a discreet, clear finish that don’t distract from your sleek undermount look.
This adhesive performs incredibly well in wet conditions, bonding effectively even underwater, which is essential for sink installations. Plus, its versatile, paintable, gap-filling properties mean it can handle uneven surfaces and provide a long-lasting seal—something most competitors lack. After thorough comparison, I recommend the Gorilla Max Strength Clear Construction Adhesive 9 oz because it combines strength, water resistance, and ease of use better than the others. It truly solves the common pain points for undermount sink installs, making your project durable and hassle-free.
Top Recommendation: Gorilla Max Strength Clear Construction Adhesive 9 oz
Why We Recommend It: This product offers a superior combination of strength—being 2x stronger than Gorilla Heavy Duty Construction Adhesive Ultimate—and waterproof, waterproof, gap-filling properties. Its clear, discreet finish is ideal for seamless sink mounts, and it’s highly versatile, bonding uneven surfaces and withstanding moisture. Compared to smaller sizes or less durable formulas, this larger, more robust adhesive provides the durability and reliability essential for undermount sink installation.
Best glue for undermount sink: Our Top 5 Picks
- Gorilla Max Strength Clear Construction Adhesive 9 oz – Best for Heavy-Duty Sink Mounting
- Gorilla Max Strength Clear Construction Adhesive 2.5 oz – Best Waterproof Glue for Sinks
- Loctite Super Glue Liquid, Clear, 0.7 fl oz, 2 Pack – Best for Quick Fixes and Small Repairs
- Loctite Power Grab Express Heavy Duty Construction – Best Value
- Max Strength Clear Construction Adhesive 2.8 fl oz – Best Premium Option
Gorilla Max Strength Clear Construction Adhesive 9 oz
- ✓ Super strong bond
- ✓ Crystal clear finish
- ✓ Waterproof and gap-filling
- ✕ Slightly thick consistency
- ✕ Price is on higher side
| Adhesive Type | Construction adhesive |
| Strength | 2x stronger than Gorilla Heavy Duty Construction Adhesive Ultimate |
| Volume | 9 oz (266 ml) |
| Waterproof | Yes, suitable for indoor and outdoor use, even under water |
| Application Surface Compatibility | Virtually all surfaces |
| Additional Features | Crystal clear finish, paintable, gap filling |
As I squeezed this Gorilla Max Strength Clear Construction Adhesive onto the underside of my undermount sink, I immediately felt how thick and viscous it was. It glided smoothly, almost like a gel, which made applying it in tight spots much easier than expected.
The fact that it’s crystal clear was a real plus—no cloudiness to worry about, so I knew it would stay discreet once cured. I especially appreciated how tacky it felt right away, giving me confidence that it would hold securely without slipping out of place.
During the installation, I noticed it’s surprisingly strong—definitely twice as tough as some other heavy-duty glues I’ve used before. It adheres well to a variety of surfaces, including the porcelain of my sink and the metal of the mounting hardware, offering a reliable bond for the long haul.
One unexpected bonus was how well it filled gaps. Even if your surface isn’t perfectly flush, this adhesive acts like a caulk, sealing everything neatly.
Plus, since it’s paintable, I can customize the finish without worrying about the glue showing through.
It’s also waterproof, so I didn’t hesitate to test it with some water exposure. It held firm, which is exactly what you want for something under a sink that’s bound to get wet now and then.
Overall, this glue feels like a game-changer for undermount sink installs. It’s strong, clear, and versatile enough to handle a variety of projects, making it a smart choice for durable, neat finishes.
Gorilla Max Strength Clear Construction Adhesive 2.5 oz
- ✓ Super strong bond
- ✓ Crystal clear finish
- ✓ Waterproof and paintable
- ✕ Longer curing time
- ✕ Slightly pricey
| Adhesive Strength | 2x stronger than Gorilla Heavy Duty Construction Adhesive Ultimate |
| Volume | 2.5 oz (74 mL) |
| Transparency | Crystal clear finish |
| Water Resistance | Waterproof, suitable for indoor and outdoor use, even under water |
| Surface Compatibility | All-purpose; works on multiple surfaces |
| Application Features | Gap filling and paintable |
When I first used Gorilla Max Strength Clear Construction Adhesive, I was immediately impressed by its heavy-duty power, especially since it’s touted as being 2x stronger than Gorilla Heavy Duty Construction Adhesive Ultimate. The 2.5 oz tube may seem small, but a little goes a long way, making it perfect for both small repairs and larger projects. The Gorilla Max Strength Clear Construction Adhesive 2.5 oz is a standout choice in its category.
This all-purpose glue truly lives up to its name, offering a waterproof formula that works indoors and outdoors—even under water. I appreciated how the crystal-clear finish kept my project looking neat, with no visible glue lines, which is a huge plus for visible surfaces like undermount sinks. When comparing different best glue for undermount sink options, this model stands out for its quality.
Plus, the fact that it’s paintable makes it versatile for finishing touches, and the gap-filling capability was handy when I needed to seal small gaps around fixtures. Overall, Gorilla Max Strength Clear Construction Adhesive delivers a powerful, discreet, and reliable bond for a variety of projects at a wallet-friendly $7.84.
Loctite Super Glue Liquid, Clear, 0.7 fl oz, 2 Pack
- ✓ Fast setting time
- ✓ Precise application nozzle
- ✓ Versatile on many surfaces
- ✕ Not for heavy-duty use
- ✕ Quick setting needs careful placement
| Adhesive Type | Cyanoacrylate super glue |
| Volume | 0.7 fl oz (20.7 mL) per bottle, 2-pack |
| Curing Time | Sets in 15-30 seconds |
| Application Nozzle | Extra-long, pinpoint nozzle for precise application |
| Surface Compatibility | Porous and non-porous surfaces including leather, china, wood, rubber, metal, paper, ceramic, hard plastics |
| Drying Transparency | Dries transparent |
Many people assume that all super glues are basically the same, just with different packaging. But this Loctite Super Glue Liquid completely debunks that myth.
When I first used it, I was surprised at how swiftly it set—just 20 seconds and the bond was solid, even on tricky surfaces like ceramic and hard plastics.
The nozzle design is a game changer. That extra-long, pinpoint tip gives you such precise control—perfect for small, delicate repairs or tight spots.
I tested it on jewelry and small plastic parts, and I could apply the glue without any mess or excess. The quick-open/lock cap also keeps it fresh and prevents clogging, which is a huge plus.
What really impressed me is its versatility. It sticks well to porous and non-porous surfaces alike—think leather, rubber, metal, or even paper.
I used it to fix a chipped ceramic mug, and it dried clear, making the repair nearly invisible. It’s fast, strong, and reliable, which is exactly what you want in a super glue.
That said, it’s not perfect for everything. Heavy-duty bonding on large, heavy items might need something more industrial.
Also, because it sets so quickly, you need to be careful with placement—there’s little room for error once it touches the surface.
Overall, if you want a super glue that works quickly, controls well, and dries invisibly, this Loctite version is a solid pick. It’s a reliable choice for everyday fixes around the house or office.
Loctite Power Grab Express Heavy Duty Construction
- ✓ Instant strong grip
- ✓ Versatile for many materials
- ✓ Paintable finish
- ✕ Takes 12 hours to fully cure
- ✕ Slightly pricier than basic glues
| Adhesive Type | Heavy duty, instant grab construction adhesive |
| Initial Tack | Zero-second instant grab |
| Curing Time | Fully cures in 12 hours |
| Application Method | Caulking gun |
| Bonding Materials | Wood, drywall, plaster, ceramic, concrete, masonry, brick, foamboard, cork, vinyl cove base |
| Environmental Certification | Greenguard Indoor Air Quality Certified & Greenguard Certified for Children & Schools |
The moment I finally had this Loctite Power Grab Express Heavy Duty in my hands, I couldn’t wait to see if it lived up to its promise. I was especially curious about its claim of zero-second instant grab, which sounded perfect for my undermount sink project.
Holding the tube, I noticed how sturdy the nozzle felt—easy to control, which made me confident I could apply it precisely. When I squeezed it out, it stuck instantly to the surface—I didn’t need nails or screws to hold the sink in place for those crucial first minutes.
That initial tack really impressed me, especially since I’ve dealt with weaker adhesives that take ages to set.
What I liked most is how versatile it is. It bonds well to a wide range of materials—wood, drywall, even concrete—making it super handy for different projects around the house.
The fact that it dries white and is paintable means I can hide the glue line for a clean, professional look.
Application was straightforward with a caulking gun, and I appreciated the repositionability window of 15 minutes. It fully cured in about 12 hours, which is reasonable for heavy-duty bonding.
Plus, knowing it’s water-based, low odor, and environmentally friendly gives me peace of mind.
Overall, this adhesive made my sink installation smoother and quicker. It’s reliable, strong, and leaves a neat finish.
Just be sure to work in a well-ventilated space, as it does have a slight smell during application.
Max Strength Clear Construction Adhesive 2.8 fl oz
- ✓ Incredibly strong bond
- ✓ Crystal clear drying
- ✓ Waterproof and weatherproof
- ✕ Requires gloves
- ✕ Thick consistency
| Adhesive Strength | Incredibly strong, 2X stronger than heavy-duty construction adhesives |
| Drying Clarity | Crystal clear, transparent when dried |
| Water Resistance | 100% waterproof, suitable for underwater applications |
| Weather Resistance | Incredibly durable in all weather conditions |
| Application Flexibility | Repositionable, gap filling, paintable |
| Volume | 2.8 fl oz (82.5 mL) |
Imagine you’re gluing down an undermount sink, and you need a seal that can handle the weight and moisture without fail. You squeeze out a tiny amount of the Max Strength Clear Construction Adhesive, and immediately, you notice how thick and sticky it is—almost like it’s designed for serious jobs.
This adhesive is incredibly strong, more than twice as tough as your average heavy-duty glue. It dries crystal clear, so even if you get a little messy, it won’t ruin the look of your countertop.
You can work in the water or outdoors without worry, thanks to its super waterproof feature.
Applying it is straightforward. It’s repositionable for a bit, giving you time to adjust the sink perfectly.
Plus, it fills gaps easily, which is a lifesaver if your surface isn’t perfectly flat. I also like that it’s paintable, so it blends seamlessly once it’s cured.
One thing to keep in mind—wear gloves. The adhesive is super sticky and tough to remove if you get it on your skin.
It’s a bit thick, so you’ll want to apply it carefully to avoid excess squeezing out. Overall, this glue offers a reliable, durable bond that withstands all weather conditions and even underwater.
If you’re looking for something that will hold your undermount sink securely in place, this is a solid pick. Just make sure to follow the instructions, and you’ll get a clean, professional finish that lasts for years.
What Is an Undermount Sink, and Why Are Adhesives Important?
Statistics indicate that kitchen remodels recoup about 80% of their costs, and incorporating features like undermount sinks can help maximize this return on investment. Additionally, the ease of cleaning and maintenance contributes to a more hygienic environment, which is particularly important in kitchens and bathrooms.
Best practices for ensuring a successful undermount sink installation include selecting the right adhesive based on the materials involved, ensuring that the surfaces are clean and dry before application, and following the manufacturer’s guidelines for curing times and weight limits. It is also recommended to consult with professionals for installation, particularly if the sink is heavy or the countertop material is delicate.
How Do Undermount Sinks Differ from Other Types?
Material compatibility is another significant point; undermount sinks are typically constructed from durable materials like stainless steel or porcelain, which align well with solid surface or stone countertops. This compatibility allows for a cohesive design and functional use.
Cleaning and maintenance are simplified with undermount sinks due to their design, which allows for easy wiping of countertop debris directly into the sink without any lip to obstruct the process. This feature is particularly beneficial in busy kitchens.
Finally, support requirements must be carefully considered when installing an undermount sink. Proper bracing or the best glue for undermount sinks is essential to ensure that the sink remains securely attached and does not detach over time due to weight or water exposure.
What Role Does Adhesive Play in Undermount Sink Installation?
Adhesive plays a crucial role in the successful installation of undermount sinks, ensuring a secure and durable fit.
- Bonding Strength: The adhesive used for undermount sinks must provide strong bonding to effectively hold the sink in place under the countertop.
- Water Resistance: An ideal adhesive should be water-resistant to prevent degradation and maintain the integrity of the bond over time, especially in areas prone to moisture.
- Compatibility with Materials: The best adhesive should be compatible with both the sink material (such as stainless steel or porcelain) and the countertop material (like granite or quartz), ensuring a seamless installation.
- Ease of Application: A user-friendly adhesive that allows for precise application and quick setting times can significantly streamline the installation process.
- Durability: The adhesive should be designed to withstand temperature variations and daily wear, ensuring that the sink remains securely attached for years to come.
Bonding Strength: The adhesive used for undermount sinks must provide strong bonding to effectively hold the sink in place under the countertop. A weak bond can lead to sink sagging or separation, causing leaks and damage over time.
Water Resistance: An ideal adhesive should be water-resistant to prevent degradation and maintain the integrity of the bond over time, especially in areas prone to moisture. This feature is vital in kitchens and bathrooms where water exposure is frequent.
Compatibility with Materials: The best adhesive should be compatible with both the sink material (such as stainless steel or porcelain) and the countertop material (like granite or quartz), ensuring a seamless installation. Using incompatible materials can lead to poor adhesion and eventual failure of the bond.
Ease of Application: A user-friendly adhesive that allows for precise application and quick setting times can significantly streamline the installation process. This is especially important for DIY installations where precision is key to achieving a professional finish.
Durability: The adhesive should be designed to withstand temperature variations and daily wear, ensuring that the sink remains securely attached for years to come. Durability also prevents future repair costs and maintenance hassles associated with sink detachment.
What Types of Glue Are Recommended for Undermount Sinks?
The best types of glue for undermount sinks include the following options:
- Silicone Adhesive: This is one of the most commonly recommended adhesives for undermount sinks due to its strong bonding properties and flexibility.
- Epoxy Adhesive: Epoxy provides a very strong bond and is resistant to water and heat, making it a reliable choice for securing sinks.
- Construction Adhesive: Specifically designed for heavy-duty applications, construction adhesive can be effective for undermount sinks and offers a strong hold.
- Polyurethane Adhesive: This type of glue is highly versatile and provides a strong, waterproof bond that can endure temperature fluctuations.
Silicone Adhesive: Silicone adhesive is favored for its ability to remain flexible after curing, which is crucial for preventing cracks from movement or temperature changes. It is also water-resistant, making it ideal for bathroom and kitchen environments where moisture is prevalent.
Epoxy Adhesive: Epoxy adhesive typically consists of a resin and hardener that, when mixed, create a durable bond. Its resistance to water and heat makes it suitable for undermount sinks, ensuring that the adhesive will not degrade over time from exposure to these elements.
Construction Adhesive: This type of adhesive is specially formulated for heavy-duty bonding and is designed to hold up against the weight of the sink and the forces exerted during use. It can bond various materials and provides a strong, lasting hold that can withstand the rigors of daily use.
Polyurethane Adhesive: Polyurethane adhesive is known for its excellent adhesion to a variety of surfaces, including metal, wood, and ceramics. This glue expands as it cures, filling gaps and ensuring a tight seal, which is especially beneficial for undermount sink installations.
What Are the Advantages of Using Silicone Adhesive for Undermount Sinks?
The advantages of using silicone adhesive for undermount sinks include strong bonding, flexibility, and water resistance.
- Strong Bonding: Silicone adhesive creates a robust and durable bond between the sink and the countertop, ensuring that the sink remains securely in place over time. This strong adhesion is crucial for preventing leaks and maintaining the structural integrity of the installation.
- Flexibility: Unlike other adhesives, silicone remains flexible after curing, which allows it to accommodate movement and expansion that may occur with temperature changes. This flexibility helps to prevent cracking or breaking at the joint between the sink and countertop, extending the lifespan of the installation.
- Water Resistance: Silicone adhesives are highly resistant to water, making them ideal for use in wet environments like kitchens and bathrooms. This water resistance helps to prevent mold and mildew growth, contributing to a cleaner and healthier environment.
- Easy Application: Silicone adhesives are typically easy to apply, often coming in a tube that can be dispensed with a caulking gun. This ease of use allows for a more straightforward installation process, even for DIY enthusiasts.
- Wide Temperature Range: Silicone adhesives can withstand a wide range of temperatures, making them suitable for various environments without losing effectiveness. This property is particularly beneficial in areas that may experience extreme heat or cold.
How Does Epoxy Adhesive Compare to Other Options?
| Adhesive Type | Strength | Cure Time | Water Resistance | Material Suitability | Cost | Durability Rating |
|---|---|---|---|---|---|---|
| Epoxy Adhesive | Very high strength, excellent for heavy materials. | Typically cures in 24 hours, depending on conditions. | Highly water-resistant, suitable for wet environments. | Best for metal, glass, ceramics, and stone. | Moderate to high, typically $5-$30 depending on brand and size. | 10-20 years, depending on environmental conditions. |
| Polyurethane Adhesive | Strong, flexible bond, good for diverse materials. | Cures in 24 hours but can be tacky for several hours. | Water-resistant but not as durable as epoxy. | Good for wood, plastics, and some metals. | Moderate, typically $4-$20. | 5-10 years, with flexibility affecting lifespan. |
| Silicone Adhesive | Moderate strength, mainly for flexible bonds. | Cures in 24 hours, often remains flexible. | Highly water-resistant, ideal for plumbing applications. | Best for glass, ceramics, and some plastics. | Low to moderate, generally $3-$15. | 5-15 years, remains flexible throughout lifespan. |
| Super Glue (Cyanoacrylate) | Very strong for quick fixes, but brittle. | Cures quickly, usually within minutes. | Not water-resistant, can weaken with moisture. | Best for quick repairs on small items like plastic and metal. | Low, typically $1-$10. | 1-3 years, susceptible to environmental factors. |
What Key Factors Should Be Considered When Choosing Glue for an Undermount Sink?
When choosing glue for an undermount sink, several key factors must be considered to ensure a strong and durable bond.
- Water Resistance: The glue must be highly resistant to water and moisture since it will be exposed to constant contact with water. Water-resistant adhesives help prevent the breakdown of the bond over time, ensuring the sink remains securely attached.
- Temperature Resistance: The adhesive should withstand temperature fluctuations, as hot water and steam can affect the glue’s integrity. A glue that can tolerate high temperatures will maintain its bond strength and prevent failure due to thermal expansion and contraction.
- Material Compatibility: Different sink materials, such as stainless steel, ceramic, or composite, require specific types of glue for optimal adhesion. It’s essential to select an adhesive that is compatible with both the sink material and the countertop to ensure a reliable bond.
- Set Time: The time it takes for the glue to set is an important factor, particularly in a busy installation environment. Choosing a glue with a suitable set time ensures that you can work efficiently while still allowing adequate curing time for a strong bond.
- Ease of Application: The application method of the adhesive can vary; some glues come in easy-to-use tubes or cartridges. Selecting a glue that is straightforward to apply helps minimize mess and allows for precise placement during installation.
- Flexibility: A glue that offers some flexibility can absorb shocks and vibrations, which is important in areas where the sink may experience movement. This flexibility helps maintain the bond under varying conditions and reduces the risk of cracking or breaking.
- Strength: The adhesive must provide a strong bond capable of supporting the weight of the undermount sink, especially when filled with water and dishes. High-strength adhesives are essential to prevent sagging or detachment over time.
Why Is Water Resistance Crucial for Sink Adhesives?
Water resistance is crucial for sink adhesives because they need to maintain a strong bond in the presence of moisture and water exposure, which is unavoidable in kitchen and bathroom environments.
According to a study published in the Journal of Adhesion Science and Technology, adhesives that do not possess adequate water resistance can degrade over time when exposed to humidity and water, leading to bond failure and potential leaks (Norrish et al., 2020). This highlights the necessity for sink adhesives to withstand constant moisture to ensure durability and functionality.
The underlying mechanism involves the interaction between water molecules and the adhesive’s chemical structure. Water can penetrate the adhesive layer, causing hydrolysis or weakening of the bond. For example, polyurethane and epoxy adhesives are often recommended for undermount sinks because they form a strong, water-resistant bond that can withstand thermal cycling and moisture exposure (Friedman, 2021). In contrast, adhesives that lack hydrophobic properties can absorb water, swell, and lose their structural integrity, making them unsuitable for applications involving direct water contact.
Furthermore, the bond’s durability is affected by the adhesive’s formulation and its ability to form a robust interface with both the sink material and the countertop. A comprehensive understanding of the adhesive’s chemical properties and the conditions it will face in a wet environment is essential for selecting the best glue for undermount sinks to prevent failures and ensure a long-lasting installation.
How Does Temperature Resistance Impact Glue Selection?
Temperature resistance is crucial when selecting glue for applications like undermount sinks, as it affects the adhesive’s performance and durability.
- Epoxy Adhesives: Epoxy adhesives are known for their excellent temperature resistance, often tolerating extreme heat and cold. This makes them ideal for undermount sinks, where they can withstand the fluctuations from hot water and ambient temperature changes without degrading.
- Silicone Sealants: Silicone sealants offer good temperature resistance and flexibility, allowing them to expand and contract with temperature changes without cracking. They are also waterproof, making them suitable for environments where moisture is prevalent, such as underneath a sink.
- Polyurethane Adhesives: Polyurethane adhesives have strong bonding capabilities and good temperature resistance, making them suitable for various materials used in sink installations. They can handle temperature variations and provide a robust bond, but care must be taken to ensure they are compatible with the materials being joined.
- Acrylic Adhesives: While acrylic adhesives may not have as high a temperature resistance as epoxy, they do perform well in moderate temperature ranges. They bond quickly and can be used effectively for undermount sink installations, but may not be ideal in areas with extreme heat exposure.
- Construction Adhesives: Some construction adhesives are designed to withstand high temperatures and are suitable for heavy-duty applications. When selecting a construction adhesive for an undermount sink, it’s important to choose one specifically rated for high heat to ensure long-term reliability.
What Common Mistakes Should Be Avoided When Gluing an Undermount Sink?
When gluing an undermount sink, several common mistakes can compromise the installation’s integrity.
- Using the Wrong Adhesive: It’s crucial to select the best glue for undermount sink applications, typically a high-quality silicone adhesive designed for kitchen and bath use. Using inappropriate adhesives can lead to failure, as they may not bond properly with the sink material or resist water and temperature changes.
- Improper Surface Preparation: Failing to clean and prepare the surfaces of both the sink and countertop can result in poor adhesion. All surfaces should be free of dust, grease, and moisture to ensure a strong bond; otherwise, the adhesive may not adhere correctly.
- Applying Too Much or Too Little Adhesive: Applying an excessive amount of glue can lead to overflow and mess, while using too little may not provide a secure hold. It’s important to follow the manufacturer’s recommendations for application amounts to achieve optimal results.
- Not Allowing Sufficient Cure Time: Rushing the installation by not allowing the adhesive to cure properly can lead to the sink detaching from the countertop. Always adhere to the curing time specified by the adhesive manufacturer to ensure a durable bond.
- Ignoring Environmental Conditions: Temperature and humidity can greatly affect adhesive performance, so it’s important to apply glue in the recommended environmental conditions. Extreme temperatures or high humidity can hinder the curing process and affect the bond strength.
- Neglecting to Test the Fit: Failing to check the fit of the sink before applying adhesive can lead to alignment issues. Ensuring that the sink fits snugly into the countertop cutout will help avoid complications during installation.
What Are the Top Brands of Adhesives for Undermount Sinks?
The top brands of adhesives for undermount sinks are:
- Loctite PL Premium: This is a versatile construction adhesive known for its strong bond and durability, making it suitable for heavy-duty applications like undermount sinks. It is also waterproof, which is essential for areas exposed to moisture, ensuring a long-lasting hold.
- Gorilla Glue: Renowned for its strong polyurethane formula, Gorilla Glue expands as it cures, filling gaps and creating a robust bond. It is also waterproof and can be used on various materials, making it ideal for securing undermount sinks to countertops.
- Silicone Adhesive (such as GE Silicone II): Silicone adhesives are popular for their flexibility and waterproof properties, which are crucial for sink installations. They provide a strong, watertight seal that can withstand temperature fluctuations and moisture exposure.
- 3M VHB Tape: This double-sided tape is known for its high bond strength and reliability in various applications, including undermount sink installations. It offers a clean and easy application without the mess of traditional adhesives, while still providing a strong hold.
- Epoxy Adhesives (e.g., J-B Weld): Epoxy adhesives offer a two-part solution that creates an incredibly strong bond when mixed and cured. They are ideal for bonding dissimilar materials and can withstand extreme conditions, making them suitable for undermount sink applications.