Top 10 Best waterproof sealant mastic in 2026

Last Updated - 6/19/2026

🏆Best Choice

Rectorseal

Rectorseal 81880 1-Pound Duct Seal Compound Gray

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•APPLICATION: Rectorseal duct seal compound is a gray, soft, non-toxic, putty-type compound that adheres to most clean dry surfaces; Duct Seal can be hand-molded to any form and reused if necessary
•EASY TO USE: The putty like duct sealant compound is easy to use and can be hand applied from 25°f to 120°f; can be applied to electrical conduit ends and boxes, flashings, and service mast entries
•SUPERIOR FORMULA: Duct seal creates an air and water tight seal; resistant to water, alcohol, and mild acids and bases; duct seal compound is asbestos-free; it will not damage plastic materials, corrode metals, or have adverse effect on human skin
•SPECIFICATIONS: Duct seal compound; grey in color and putty like; non-corrosive and non-irritant; can be hand-shaped to any form and reused if necessary, has many applications in hvac/r, plumbing, metal fabrication, and a superb general purpose sealant around the home; may be painted immediately after applying and won't bleed through dry paint film
•FOR THE TRADESMAN: RectorSeal is recognized as a leading provider of quality solutions for the professional trades serving heating, ventilation, and air conditioning (HVAC/R), plumbing, electrical, and construction markets

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$5.09

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ZFYOUNG

ZFYOUNG 10-Pack Premium Waterproof Wall Repair Sealing Clay Duct Seal Ideal for Wall Hole Repair, Air Conditioning and Drainage Pipes Quick and Easy Solution

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•(Product packaging): Our sealing mud comes in 10 bags per pack, and each bag weighs 30 grams. This clay provides long-lasting protection.
•(Product Usage): Our Quick Repair Putty is a versatile product that can be used for a variety of purposes. Whether you need to repair a pipe connection, wall hole or air conditioning opening, our sealing clay is the ideal solution to fix the leak
•(Product Features): Our sealed ducts are flexible and easy to use. Once blended, it becomes soft and malleable, allowing you to shape it however you want. Just fill the hole and let it dry for 3-5 days. The result is a strong, reliable seal that will stand the test of time.
•(Product Material): Our sealing clay is designed to seamlessly repair and fill wall holes, including air conditioning holes and pipe holes. Its white color pairs perfectly with white walls, ensuring an understated yet professional finish.
•(Product Commitment):If there is any quality problem, please contact us in time to deal with it and give you a satisfactory answer.

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$12.85

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ZXFUTURE

Zxfuture Pack of 8 White Seal Putty Waterproof Duct Seal Repair Sealing Clay, Quick Mending Mud for Drain Connection, Wall Hole, Air Conditioning Hole

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•Easy to Use and Shape: Our waterproof repair sealing clay is soft and flexible, making it an ideal solution for hole filler, wall putty for filling holes, wall repair, and as a plumbers putty for sink drains. Simply fill it in and let it dry for 3-5 days to achieve a sturdy seal.
•Multipurpose: Our sealing clay is a versatile solution for your repair needs. It can be used as a hole filler putty for walls, a duct seal putty, a waterproof insulating sealant, and as a putty for wall holes. It is also effective at preventing smells.
•Waterproof : Our sealing clay is not only waterproof but also a great waterproof sealant. It works great as a wall putty for filling holes and as a sealant for any surface that requires waterproofing.
•Tips for Use: To get the best results, make sure to clean the surface before applying the sealing clay and avoid using it on wet or damp surfaces. It is also important to allow the clay to dry for 3-5 days before exposing it to any moisture. Our sealing clay is a great wall putty option for any repair job.
•Convenient Packaging: Our waterproof repair sealing clay comes in a package of 8 bags, each weighing 30g. This makes it easy to store and use as needed, without wasting any excess product. It is the perfect wall putty solution for all of your repair needs, including hole filler putty for walls and putty for wall holes.

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$12.46

$13.85

-10%

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KEPTFIT

6-Pack New Type White Waterproof Sealant Mastic, Repair Sealing Clay, Quick Mending Mud for Drain Connection, Wall Hole, Air Conditioning Hole Waterproof Seal Putty

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•Easy to Shape and Apply- Our waterproof repair sealing clay is soft and flexible, making it perfect for filling holes, wall repair, and plumbing fixes like sink drains. Just mold it into place and let it dry for 2-3 days to create a strong, reliable seal.
•Versatile Repair Solution- This multi-purpose sealing clay works as a hole filler, duct sealant, wall putty, and waterproof insulating sealant. It's also effective at blocking odors, making it a must-have for various household repairs.
•Waterproof and Durable- Designed to provide a strong waterproof seal, this clay is ideal for filling wall holes and sealing any surface that requires protection from moisture.
•Helpful Tips for Best Results- Always clean the surface thoroughly before applying and avoid wet or damp areas. Allow the clay to dry completely for 3-5 days before exposing it to water for optimal performance.
•Convenient 6 Pack- Each package includes 8 bags of sealing clay, with each bag weighing 30g. This thoughtful packaging makes it easy to store and use only what you need, reducing waste. Whether it's wall repair or duct sealing, this is the ultimate solution for your repair needs.

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$9.39

$9.99

-6%

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TIANKEYYDS

TIANKEYYDS New Type 10 White Seal Putty Waterproof Duct Seal Repair Sealing Clay, Quick Mending Mud for Drain Connection, Wall Hole, Air Conditioning Hole

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•Easy to Use and Shape: Our waterproof repair sealing clay is soft and flexible, making it an ideal solution for hole filler, wall putty for filling holes, wall repair, and as a plumbers putty for sink drains. Simply fill it in and let it dry for 3-5 days to achieve a sturdy seal.
•Multipurpose: Our sealing clay is a versatile solution for your repair needs. It can be used as a hole filler putty for walls, a duct seal putty, a waterproof insulating sealant, and as a putty for wall holes. It is also effective at preventing smells.
•Waterproof : Our sealing clay is not only waterproof but also a great waterproof sealant. It works great as a wall putty for filling holes and as a sealant for any surface that requires waterproofing.
•Tips for Use: To get the best results, make sure to clean the surface before applying the sealing clay and avoid using it on wet or damp surfaces. It is also important to allow the clay to dry for 3-5 days before exposing it to any moisture. Our sealing clay is a great wall putty option for any repair job.
•Convenient Packaging: Our waterproof repair sealing clay comes in a package of 10 bags, each weighing 20g. This makes it easy to store and use as needed, without wasting any excess product. It is the perfect wall putty solution for all of your repair needs, including hole filler putty for walls and putty for wall holes.

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$9.58

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Generic

3-Pack Waterproof Sealant Mastic, 2025 New Repair Sealing Clay, for Wall Hole Repair, Air Conditioning and Drainage Pipes Quick and Easy Solution

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•Easy to Use & Quick Repair – Our waterproof repair sealing clay is soft and pliable, making it simple to fill cracks, holes, and gaps. Just apply, smooth, and let it dry for a sturdy, seamless finish. Perfect for quick fixes around the home
•Multi-Purpose Repair Solution – This versatile sealing clay works as a wall filler, crack sealer, and surface leveler. Ideal for drywall, plaster, and concrete repairs, making it a must-have for various household repairs
•Strong & Long-Lasting – Designed to dry hard and resist cracking, our repair paste ensures a durable finish. Once set, it won’t shrink or crumble, providing a reliable solution for wall imperfections
•Pro Tips for Best Results – Clean the damaged area before application and ensure it’s dry. Knead the putty for flexibility, apply evenly, and let it cure fully. The 3pcs pack ensures you have enough for multiple repairs without waste
•Convenient 3 Pack – Giving you plenty for multiple projects. Compact and easy to store, it’s a must-have for homeowners and professionals alike.The 3pcs pack ensures you have enough for multiple repairs without waste

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$12.99

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yxgjmygs

Yxgjmygs 8 Packs of White Sealing Putty for Pipeline Sealing Repair, Sealing Clay for Pipeline Connection Quick Repair, mud for Wall Holes, air Conditioning Holes

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•Soft-textured clay seamlessly adapts to wall voids and irregular gaps by hand. No professional equipment needed – press into place and cure for 3-5 days to form durable seals.
•Usage tip: To achieve the best results, be sure to clean the surface, keep it dry, and avoid using it on damp surfaces before using sealant. Drying for 3-5 days can cure. Our sealing clay is the best choice for any maintenance personnel.
•Reasonable packaging allocation for easy use and storage: Our repair sealed clay comes in 8 bags per pack, each weighing 30 grams. The outer packaging features a sealable pocket design for easy storage and organization. Each pack contains 30 grams of small repairs with zero waste, making it an ideal product for home backup.
•Multipurpose: It can be used as a hole filler putty for walls, a duct seal putty, a waterproof insulating sealant, and as a putty for wall holes. It is also effective at preventing smells.
•It works great as a wall putty for filling holes and as a sealant for any surface that requires waterproofing.

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$8.98

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gotosee

Waterproof Duct Seal Repair Sealing Clay 8 Pack White Moldable Silicone Putty, Quick Mending Mud for Pipe Connection, Wall Hole, Air Conditioning Holes (8)

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•Waterproof Repair Sealers Caulk Repair Walls and Pipes Automatic Curing, Fire and Oxidation Resistance
•Sealers, an environmentally friendly material, can be kneaded into any shape to repair the wall.
•The clay is fine, high-density, waterproof, oil-proof, and has a very good sealing performance.
•Corrosion resistance, oxidation resistance, no yellowing, durable.Individually packaged, easy to use.
•Heat-resistant and flame-retardant, self-hardening, keep mosquitoes, spiders, snakes, etc. out.Tips:3-4 days needs for dry in winter,and not suit for repairing pipe leaking
•How to Use:Open the packaging, take out the sealant mud, mix it with your fingers, and use it.Tips：before using,please clean the hole make sure no water or dust.

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$8.99

$9.69

-7%

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dhlhdo

Waterproof Sealant Mastic, 2025 New Repair Sealing Clay Wall Gaps Filler, Quick Mending Mud for Drain Connection, Wall Hole, Air Conditioning Hole Waterproof Seal Putty (0.06 pounds/Pack) (6)

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•New Type Waterproof Sealant Mastic: A new type of waterproofing sealant, which quickly seals all kinds of holes and gaps: rat hole, cracks, pipe hole, wall hole.etc. Making it the ideal solution for filling holes and cracks in pipes to prevent various leaks, helps keep interiors dry and secure in rainy or humid conditions
•Highly Flexible & Durable: Featuring high plasticity, this sealant can be molded into various shapes, including round, square, or long. This flexibility guarantees a perfect fit for any hole or crack, making it incredibly easy and convenient to use. The mastic sealant contains a cooling adhesive component that quickly hardens in the presence of wind, ensuring a speedy and efficient sealing process.
•Easy to Use: First clean the gap that needs to be sealed to ensure that there is no dust, water and other debris. 1. Reshape the clay according to the size of the holes/gaps. 2. It can blend perfectly with the surface. Just leave it for a few hours to air dry.
•Repair Sealing Clay: Waterproof repair sealing clay is a fast solution to fill holes or cracks! Perfect protective finish for flat roofs, metal roofs, sloped roofs, planter boxes, foundations, sheds, basements, metal, wood, concrete and more.
•Widely Used: The waterproof sealant mastic putty can be used for wall repair and crack filling repair (such as air conditioning pipes, rat holes, etc.), can also be used for various pipe fittings, equipments installation, fixing and repair.

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$16.99

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GROTOLY

GROTOLY 6-Pack Waterproof Sealant Mastic,White Duct Seal Repair Sealing Clay,Quick Mending Mud for Wall Hole,Drain Connection, Air Conditioning Hole

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•Easy to Apply & Versatile: Our waterproof sealant mastic is soft and moldable, perfect as a wall putty hole repair, duct seal putty, or plumbers putty for sink drain;Simply knead, apply, and let it dry for a durable, airtight seal—ideal for hole filler putty for walls and more
•Multi-Purpose Sealant Clay:Our sealant clay waterproof works for endless fixes—use it as a putty for wall holes, pipe sealant, or wall hole filler;It blocks leaks, and adheres firmly to various surfaces, making repairs effortless
•Superior Waterproof Protection: Designed as a waterproof sealant mastic, it creates a moisture-resistant barrier for sinks, ducts, and walls;Whether sealing cracks or gaps, it ensures long-lasting waterproof insulating sealant performance
•Pro Tips for Best Results: Clean and dry surfaces before applying our sealant clay;Avoid wet areas during application, and allow 3-5 days to cure fully;Good plumbers putty or wall putty hole repair for flawless results
•Compact & Practical Packaging: Each order includes 6 resealable 20g bags sealant clay, ensuring easy storage and minimal waste;Quick fix like hole filler putty for walls or duct seal putty

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$16.99

$18.99

-11%

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