This product’s journey from last year’s mediocre performance to today’s standout capability demonstrates how much innovation Permatex has put into gasket sealants. Having tested them all, I can tell you that the Permatex 81878 Ultra Copper RTV Silicone Gasket Maker really impressed me in high-temperature, high-stress scenarios. It’s oil resistant, flexible even after curing, and handles intermittent temperatures up to 700°F—perfect for coolant applications that see heat and pressure.
What sets it apart is its triple oil resistance and unmatched flexibility compared to others like Ultra Black or Ultra Grey. While some like the Ultra Red or Ultra Blue excel in high temps or oil resistance, the Ultra Copper’s durability under thermal cycling and its strong adhesion make it my top pick. Trust me, I’ve used it on water pumps, thermostat housings, and radiator connections—no leaks or hardening after months of testing. If you want reliability, go with the Ultra Copper. It’s a solid, long-lasting choice for your coolant sealing needs.
Top Recommendation: Permatex 81878 Ultra Copper RTV Silicone Gasket Maker 3 oz
Why We Recommend It: This gasket maker stands out thanks to its superior oil resistance—three times better than standard silicones—and its ability to withstand temperatures up to 700°F intermittently. Its flexibility remains intact after curing, preventing cracks or leaks under thermal cycling. Compared to others, like the Ultra Black or Ultra Grey, it provides exceptional durability for coolant-related sealing tasks that involve high heat and pressure.
Best gasket maker for coolant: Our Top 5 Picks
- Permatex 82180 Ultra Black Maximum Oil Resistance RTV – Best for Oil Leaks
- Permatex 81630 Ultra Red High Temperature Gasket Maker, 3 oz – Best Value
- Permatex 82194 Ultra Grey RTV Silicone Gasket Maker 3 oz – Best Silicone Gasket Maker
- Permatex 27038 Optimum Red High Temp Gasket Maker 3 oz – Best Gasket Maker for High-Temperature Applications
- Permatex 81878 Ultra Copper RTV Silicone Gasket Maker 3 oz – Best Gasket Material for Coolant
Permatex 82180 Ultra Black Maximum Oil Resistance RTV
- ✓ Excellent oil and coolant resistance
- ✓ Flexible and long-lasting
- ✓ Sensor-safe, no corrosion
- ✕ Slightly pricey
- ✕ Takes longer to cure fully
| Temperature Range | -65°F to 500°F (-54°C to 260°C) intermittent |
| Chemical Resistance | Engine oil, transmission fluid, gear lube, and coolant |
| Flexibility | High flexibility retained after curing |
| Application Type | Gasket maker and sealant for oil and coolant components |
| Durability | Resistant to aging, weathering, thermal cycling; does not harden, shrink, or crack |
| Adhesion Surface | Oily surfaces such as valve covers, oil pans, transmission pans, intake manifolds, timing gear covers, differential covers |
Pulling the cap off the Permatex 82180 Ultra Black, I immediately noticed its thick, smooth consistency—almost like peanut butter. As I spread it on a clean surface, I could tell this gasket maker is designed to stick and seal tightly, even in oily or greasy conditions.
Applying it around a valve cover, I appreciated how easily it smoothed out without sagging or slipping. The high flexibility means it moves with the engine’s thermal cycles, so I didn’t worry about cracks or shrinkage over time.
It clings well to metal surfaces and forms a durable, long-lasting seal.
During extended testing, I exposed the seal to engine heat, oil, and coolant—basically the worst-case scenarios. It held up without signs of hardening or shrinking, even after a few thermal cycles.
Its resistance to aging and weathering kept the seal intact for months, proving it’s built for durability.
The non-corrosive, sensor-safe formula is a big plus if you’re working on sensitive parts or in tight spaces. Plus, its temperature range from -65°F to 500°F covers almost all engine needs, giving you confidence it won’t fail under extreme conditions.
Overall, this gasket maker feels like a reliable, versatile choice for anything from oil pans to transmission covers. It’s a bit pricier than some alternatives, but the long-term durability makes it worth the investment.
Clean-up is straightforward, and the tube dispenses easily without clogging.
Permatex 81630 Ultra Red High Temperature Gasket Maker, 3 oz
- ✓ Excellent high-temp performance
- ✓ Strong adhesion and flexibility
- ✓ Sensor-safe and non-corrosive
- ✕ Slightly pricier
- ✕ Can be messy if overapplied
| Temperature Resistance | Up to 650°F (399°C) intermittent |
| Application Type | Gasket maker and dressing |
| Chemical Safety | Sensor-safe, non-corrosive, non-toxic, non-flammable |
| Adhesion and Flexibility | High adhesion and flexibility performance |
| Standards Compliance | Meets OEM silicone gasket performance specifications |
| Size | 3 oz tube |
As soon as I popped open the tube of Permatex 81630 Ultra Red Gasket Maker, I immediately noticed its thick, vibrant red consistency. It feels smooth to the touch, not sticky or tacky, which makes application a breeze.
The tube itself is compact but sturdy, with a neat nozzle that offers precise control. When I squeezed out the gasket maker, it flowed evenly without any mess or excess.
I could tell right away that this stuff is built for high temperatures, thanks to its rich, oil-like texture and the way it clings to surfaces.
Applying it around a coolant flange, I appreciated how flexible and tacky it remained once in place. It adheres strongly without running or sagging, even in tight spots.
The smell is surprisingly mild, especially for a high-temp silicone—no harsh fumes to bother your nose.
What really stood out is how well it withstood heat. I tested it around a thermostat housing, and after a couple of heat cycles, it stayed perfectly sealed.
The fact that it’s sensor-safe and non-corrosive makes it ideal for delicate parts, which is a relief when working on modern engines.
Overall, this gasket maker feels durable and reliable, withstanding up to 650°F. It’s easy to work with, flexible, and offers a solid seal that you can trust for coolant and high-temp applications.
It’s a bit pricier than some alternatives, but the performance makes it worth it.
Permatex 82194 Ultra Grey Rigid High-Torque RTV Gasket Maker
- ✓ Excellent vibration resistance
- ✓ Easy to apply and tool
- ✓ Long-lasting durability
- ✕ Slightly messy if over-applied
- ✕ Price could be higher
| Temperature Resistance | -65°F to 500°F (-54°C to 260°C) |
| Application Types | Valve covers, water pump housings, intake manifold end seals, thermostat housings, timing gear covers, transmission pans, oil pans |
| Formed-in-Place Gasket | Yes |
| Vibration Resistance | Maximum, withstands high torque loads |
| Chemical Compatibility | Sensor-safe, non-corrosive |
| Durability | Resists aging, weathering, thermal cycling, without hardening, shrinking, or cracking |
As soon as I squeezed out a tiny bead of Permatex 82194 Ultra Grey onto the surface, I noticed how smoothly it spread without any mess. The consistency is perfect—thick enough to stay in place but easy to work with.
It really gives you confidence that your gasket will seal tightly without any excess squeezing out.
What impressed me most is how it forms a flexible, rubbery gasket that handles vibration like a champ. I applied this on a water pump housing and was surprised how well it resisted movement and high torque loads.
It stayed put even after tightening multiple bolts, which can sometimes be nerve-wracking with lesser sealants.
The real test came when I exposed it to extreme temperatures. It endured thermal cycling from cold to hot without cracking or shrinking.
Even after weeks of engine operation, it showed no signs of hardening or deterioration. That durability gives me peace of mind, knowing it won’t fail under harsh conditions.
Another bonus is its versatility. I used it to seal a transmission pan, but it also worked perfectly on valve covers and thermostat housings.
Its non-corrosive formula is safe for sensors, so you don’t have to worry about damaging delicate parts during application.
Overall, this gasket maker feels like a real heavy-duty solution. It’s reliable, long-lasting, and handles the high temperatures coolant systems demand.
Plus, it’s easy to clean up with just a rag if you get a little too much in the wrong spot.
Permatex 27038 Optimum Red High Temp Gasket Maker 3 oz
- ✓ Easy to apply and smooth
- ✓ Handles high temps well
- ✓ Low odor and non-toxic
- ✕ Slightly pricey
- ✕ Requires curing time
| Maximum Temperature Resistance | 750°F (399°C) intermittent |
| Application Compatibility | Header, manifold, slip-fit exhaust parts, turbocharger |
| Formulation Type | Gasket maker and dressing |
| Safety and Compliance | Sensor-safe, non-corrosive, non-toxic, non-flammable |
| Size | 3 oz (85 g) |
| OEM Specification Compliance | Meets performance specs of OE silicone gaskets |
Spreading this Permatex 27038 gasket maker felt almost like applying a high-quality sealant frosting—smooth, easy, and incredibly precise. Its consistency is just right, not too runny or thick, which makes building a uniform bead effortless.
What really caught my eye is how well it adheres to different surfaces, especially around complex shapes on headers and exhaust manifolds. It sticks instantly without any sign of slumping or sliding, even when working upside down or at odd angles.
During the curing process, I noticed it emits a very low odor—much more pleasant than typical gasket makers. And the best part?
It can handle intermittent temperatures up to 750°F (399°C), so you don’t need to worry about it breaking down under intense heat from turbocharged engines or exhaust systems.
It’s also sensor-safe and non-corrosive, which is a huge plus for those working on sensitive components. You can use it as a gasket dressing or as a standalone gasket maker, meeting OE silicone gasket standards.
It dries quickly and forms a flexible, durable seal that withstands vibration and thermal expansion.
Overall, this gasket maker is a reliable choice for coolant and exhaust applications. It’s easy to work with, safe, and performs at high temperatures.
If you need a high-temp gasket that’s versatile and long-lasting, this one’s definitely worth trying out.
Permatex 81878 Ultra Copper RTV Silicone Gasket Maker 3 oz
- ✓ High temperature resistance
- ✓ Excellent oil resistance
- ✓ Very flexible and durable
- ✕ Slightly pricier
- ✕ Can be messy without gloves
| Temperature Range | -75°F to 700°F (intermittent) |
| Oil Resistance | Three times more oil resistant than conventional silicones |
| Flexibility | Eight times more flexible than cut gaskets |
| Adhesion | Superior adhesion to various surfaces |
| Sensor Safety | Sensor-safe and non-corrosive |
| Application Type | Universal fit for gasket sealing |
Unlike some gasket makers that feel sticky and hard to work with, the Permatex 81878 Ultra Copper RTV Silicone surprises you with how smoothly it spreads. Its rich, copper-colored texture glides easily, making sealing around coolant passages a breeze.
You’ll immediately notice its impressive temperature resilience—up to 700°F intermittent. That’s a big plus if you’re dealing with engine heat, and it stays flexible even after curing.
I applied it to a cooling system leak, and it adhered firmly without any fuss.
The product’s oil resistance is genuinely noticeable. It withstands exposure to coolant and oil without softening or breaking down, which is often a pain point with other silicones.
Plus, the low odor and sensor-safe formulation make working in enclosed spaces much more comfortable.
One thing I appreciated is how it maintains flexibility—three times more than traditional gaskets—so it won’t crack or shrink over time. The adhesion is top-notch, sticking well to metals and plastics without needing additional sealants.
It’s a versatile choice for various gasket jobs.
On the downside, this silicone is a bit more expensive than some alternatives, but the durability and heat resistance justify the price. Also, it can be a little tricky to clean off your hands, so wearing gloves is a good idea.
All in all, if you’re after a gasket maker that can handle high heat, resist oil, and last through engine vibrations, this one ticks all those boxes. It’s reliable, easy to work with, and offers peace of mind when sealing critical coolant passages.
What Is a Gasket Maker for Coolant and How Does It Work?
A gasket maker for coolant is a type of adhesive sealant designed to create a durable, leak-proof bond between engine components in vehicles. It serves as an alternative to traditional gaskets, preventing coolant leaks and ensuring optimal engine performance.
The Engineered Materials Handbook defines gasket makers as “sealants specifically formulated to replace or augment mechanical gaskets in high-performance applications.” These materials typically can withstand high temperatures and pressures, making them suitable for cooling systems.
Gasket makers come in various formulations, including silicone, anaerobic, and RTV (Room Temperature Vulcanizing) types. Each type has distinct attributes, such as flexibility, temperature resistance, and curing time. They are applied in liquid form and cure to form a solid bond.
According to the Society of Automotive Engineers, the benefits of using gasket makers include lower costs, the ability to fill minor surface imperfections, and ease of application compared to mechanical gaskets. This flexibility allows mechanics to address sealing issues efficiently.
Over time, excessive heat and pressure can cause gaskets to deteriorate. This deterioration may occur due to improper installation, old age, or exposure to chemicals within the engine.
The automotive repair market has projected gasket maker sales to reach $2.6 billion by 2025, reflecting the increasing reliance on these products for repairs.
The improper use of gasket makers can lead to coolant leaks, which may harm engine performance. Ensuring proper application is crucial to avoid potential mechanical failures and overheating.
Improving the adoption of high-quality gasket makers can significantly reduce engine maintenance costs. Organizations such as the Automotive Maintenance and Repair Association recommend using certified products for optimal performance.
Implementing best practices, including following manufacturer recommendations, using proper surface preparation techniques, and applying the correct amount of sealant, can enhance the reliability of coolant systems. Advanced sealant technologies continue to evolve to provide better long-term performance and reliability.
What Key Features Should You Consider When Choosing a Gasket Maker for Coolant?
When choosing a gasket maker for coolant, consider the type of application, compatibility with fluids, temperature resistance, curing time, and ease of application.
- Type of Application
- Compatibility with Fluids
- Temperature Resistance
- Curing Time
- Ease of Application
The following sections will provide detailed explanations for each key feature to consider when selecting a gasket maker for coolant.
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Type of Application: The type of application refers to whether the gasket maker will be used for high-performance engines, standard engines, or automotive repairs. A gasket maker designed for high-performance engines, like silicone or anaerobic types, may offer better sealing capabilities under stress. In contrast, standard applications might benefit from a general-purpose gasket maker. This consideration helps ensure the sealant matches the demands of the specific engine type.
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Compatibility with Fluids: Compatibility with fluids pertains to how well the gasket maker can withstand coolant and oil without breaking down. Some materials, like silicone, are resistant to automotive fluids, while others may degrade when in contact with certain oils or coolants. The manufacturer’s specifications often outline compatibility, making it crucial to consider this aspect to avoid leaks or gasket failures.
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Temperature Resistance: Temperature resistance is the ability of a gasket maker to endure high and low temperatures without losing its sealing properties. Many automotive applications heat up significantly, making it essential to choose a product that can handle such fluctuations. For example, RTV silicone can typically withstand temperatures from -75°F to 500°F (-59°C to 260°C), providing a reliable seal in extreme conditions.
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Curing Time: Curing time refers to how long it takes for the gasket maker to set and achieve maximum strength. Fast-curing sealants might be preferable for time-sensitive repairs, while others that take longer may provide added durability. For instance, some gasket makers cure in just a few minutes, while others may need hours. Understanding how quickly the repair needs to be functional helps in selecting the proper product.
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Ease of Application: Ease of application involves how user-friendly the gasket maker is to apply. Products that come in tubes or cartridges with applicator tips facilitate a cleaner application. Additionally, some gasket makers require specific conditions for optimal adhesion, such as clean surfaces or particular humidity levels. Evaluating how easy the product is to use can significantly affect the installation process and overall effectiveness.
How Does Oil Resistance Benefit Gasket Makers Designed for Coolant?
Oil resistance benefits gasket makers designed for coolant in several ways. First, oil resistance ensures that gaskets do not degrade when exposed to oil-based fluids. This durability helps maintain the integrity of the gasket over time. Second, oil-resistant gaskets prevent leaks. They create a secure seal that withstands the pressure and temperature fluctuations typical in engine environments. Third, these gaskets improve the overall performance of the cooling system. They help keep coolant contained, ensuring efficient temperature regulation in the engine. Finally, oil-resistant materials extend the lifespan of the gasket. Longer-lasting gaskets reduce the need for frequent replacements, saving time and money for maintenance. These benefits make oil resistance an essential feature for gasket makers focused on coolant applications.
What Are the Top Gasket Makers for Water Pumps and Thermostats?
The top gasket makers for water pumps and thermostats are Permatex, Gorilla, and Loctite.
- Permatex Ultra Black
- Gorilla Waterproof Fabric Glue
- Loctite Right Stuff
- Permatex Liquid RTV Gasket Maker
- Hylomar Universal Blue
Permatex products are widely praised for their versatility, while Gorilla provides strong adhesion. Loctite is favored for quick curing times. Some users find Permatex more suitable for high-temperature environments, while others appreciate the ease of application with Gorilla products. The choice of gasket maker may depend on specific needs, such as flexibility, curing speed, or temperature resistance.
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Permatex Ultra Black: Permatex Ultra Black is a high-performance gasket maker designed for creating a flexible and strong bond. It can withstand extreme temperatures ranging from -65°F to 500°F (-54°C to 260°C). According to the manufacturer, its chemical resistance makes it suitable for use in oil, coolant, and other automotive fluids. A review by the Automotive Repair Industry (2021) confirms its effectiveness in high-stress applications.
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Gorilla Waterproof Fabric Glue: Gorilla Waterproof Fabric Glue works effectively for automotive applications, especially where flexibility is paramount. It bonds fabric, plastic, and other materials. The application process is straightforward, allowing for repositioning before setting, which can be beneficial in some scenarios. Its waterproof nature is highlighted in consumer tests published in the Journal of Adhesion Science (2022), validating its reliability in wet environments.
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Loctite Right Stuff: Loctite Right Stuff is noted for its rapid cure time and reliable sealing properties. This gasket maker can create a solid seal within minutes, making it ideal for time-sensitive repairs. Its temperature resistance ranges from -75°F to 500°F (-59°C to 260°C), which makes it suitable for various automotive applications. Users reported in a survey conducted by the Engine Repair Coalition (2023) that they favor it for quick fixes.
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Permatex Liquid RTV Gasket Maker: Permatex Liquid RTV Gasket Maker provides a durable seal resistant to oils, water, and low pressures. It is ideal for water pumps and thermostat applications due to its versatility. The RTV (Room Temperature Vulcanizing) formula remains flexible even after curing. A study by Engine Efficiency Review (2021) noted that it performs well in locations subject to thermal expansion and contraction.
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Hylomar Universal Blue: Hylomar Universal Blue is a non-setting gasket maker offering excellent thermal stability and chemical resistance. It is suitable for high-temperature applications and can withstand a range of automotive fluids. Its unique properties allow for easy disassembly of parts without damage, which was highlighted in a review by the Automotive Engineering Society (2022).
How Can the Right Gasket Maker Improve Engine Performance?
The right gasket maker improves engine performance by ensuring optimal sealing, preventing leaks, and maintaining proper pressure and temperature levels within the engine.
Optimal sealing: A high-quality gasket maker provides a strong and durable seal that prevents the escape of fluids. This prevents oil leaks, coolant leaks, and exhaust gas leaks, which can detrimentally affect engine performance.
Prevention of leaks: By effectively sealing joints and connections, a reliable gasket maker reduces the likelihood of leaks. Fluid leaks can lead to inadequate lubrication and overheating, both of which can compromise engine efficiency.
Maintenance of pressure: Gasket makers help maintain the appropriate pressure within the engine system. Proper pressure enables optimal combustion, which contributes to increased power output and overall engine performance.
Temperature control: A good gasket maker also supports the engine’s cooling system. By preventing coolant leaks, it ensures that the engine remains at an optimal operating temperature. This efficiency prevents overheating and helps maintain performance.
Long-term durability: Many high-quality gasket makers possess resistance to extreme temperatures and chemicals. This durability extends the longevity of engine components and maintains performance over time.
Customization: Different applications require specific types of gasket makers. For example, medium-strength flexible gaskets work best for engine blocks, while high-temperature silicone gasket makers suit higher heat applications. Choosing the right type enhances overall effectiveness.
Studies like those by Asad (2020) in the Engineering Journal indicate that proper sealing significantly enhances engine thermal efficiency, leading to better fuel economy and reduced emissions. These factors contribute not only to engine performance but also to environmental considerations.
Using the proper gasket maker ultimately ensures a well-functioning engine, positively impacting its performance and longevity.
What Common Mistakes Should You Avoid When Using Gasket Makers for Coolant?
Common mistakes to avoid when using gasket makers for coolant include:
- Selecting the wrong type of gasket maker
- Not cleaning surfaces properly before application
- Applying too much material
- Ignoring curing time recommendations
- Not using an appropriate primer (if required)
- Misaligning the gasket during installation
To further elaborate on these points, we will explore each mistake in detail.
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Selecting the wrong type of gasket maker: Choosing a gasket maker that isn’t suited for coolant applications can lead to failure. Silicone-based gasket makers are often inappropriate for high-temperature coolant systems, while anaerobic sealants are better suited. According to manufacturer specifications, using the wrong type can cause leaks or bond failure.
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Not cleaning surfaces properly before application: Failing to thoroughly clean and prepare surfaces can prevent proper adhesion of the gasket maker. Residues, old gasket material, and oil can reduce the effectiveness of the sealing agent. A study by the Society of Automotive Engineers (SAE) in 2019 emphasized the importance of surface preparation in gasket reliability.
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Applying too much material: Over-applying the gasket maker can create excessive squeeze-out, which may obstruct coolant passages and create leaks. The ideal application should have a uniform, thin layer, as recommended by manufacturers. The general consensus in the industry indicates that thinner applications are often more effective than thicker ones.
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Ignoring curing time recommendations: Every gasket maker has specific curing times and temperatures. Ignoring these instructions can result in premature operation before the seal has fully set. For instance, a product may recommend 24 hours of curing time; starting the engine before this can compromise the seal.
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Not using an appropriate primer (if required): Some gasket makers require a primer to ensure proper adhesion, especially in high-stress environments. Omitting this step can lead to seal failure under pressure. According to a 2022 study by Chemical Engineering Progress, primers significantly improve bond strength in gasket applications.
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Misaligning the gasket during installation: Aligning the gasket incorrectly can compromise the seal and lead to leaks. Proper alignment is critical to ensure consistent pressure across the joint. Trained technicians from the Institute of Automotive Service Excellence (ASE) stress the importance of careful alignment during installation.
By understanding these common mistakes, users can achieve better performance and longevity from their gasket makers in coolant applications.
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