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Before comparing them, let's first define each technology.
RTV (Room Temperature Vulcanizing) silicone is a one-component, silicone-based sealant that cures at room temperature upon exposure to atmospheric moisture. Once cured, it forms a flexible, rubber-like elastomer that adheres to a wide range of substrates, including metals, plastics, and composites. Its elasticity allows it to absorb vibration, thermal expansion, and joint movement while maintaining a durable seal.
RTV silicones are widely used as Formed-In-Place Gaskets (FIPG), replacing conventional pre-cut gaskets in many automotive and industrial assemblies.
Although RTV silicones are technically a type of liquid gasket, this article uses the term "liquid gasket" to refer specifically to non-silicone liquid gasket technologies, such as the ThreeBond 1100 Series.
Like RTV silicones, they are applied directly onto the sealing surface before assembly, where they cure to fill microscopic surface imperfections and create a leak-tight seal. However, unlike RTV silicones, they generally provide higher oil and fuel resistance, lower permeability, and reduced contamination risk in sensitive systems. Depending on the formulation, some liquid gaskets remain flexible after curing, while others form a more rigid or semi-flexible seal designed for high-pressure or chemically aggressive environments.
Both RTV silicones and non-silicone liquid gaskets eliminate the need for conventional cut gaskets, but their curing mechanisms, mechanical properties, and chemical resistance make them suitable for different applications.
Choose RTV silicone when flexibility, vibration resistance, or gap-filling capability is required. Opt for a non-silicone liquid gasket when working with precision-machined flanges, threaded joints, or applications requiring a very thin sealing film and excellent fluid resistance.
RTV SILICONE (TB1200 SERIES)
RTV silicone sealants are typically selected for applications requiring flexibility, vibration resistance, and accommodation of thermal expansion, including:
Available in several cure chemistries, including oxime, acetone, and alcohol-based formulations, the 1200 Series can be selected to meet specific substrate compatibility and manufacturing requirements. Designed for Formed-In-Place Gasket (FIPG) applications, these sealants effectively replace conventional pre-cut gaskets on engine and transmission components, electrical housings, battery enclosures, pumps, and a wide variety of industrial equipment.
NON-SILICONE LIQUID GASKETS (TB1100 SERIES)
Non-silicone liquid gaskets are generally preferred where a thin sealing film, excellent fluid resistance, or easy maintenance is required, including:
Depending on the grade, the 1100 Series offers solutions ranging from non-setting compounds that facilitate easy maintenance and repeated disassembly to high-strength anaerobic sealants designed for permanent sealing under high pressure. Applied as a thin, uniform film, these products effectively fill surface imperfections while minimizing material consumption, helping manufacturers reduce waste and achieve reliable, long-lasting sealing performance.
What is the difference between RTV silicones and Non-silicone Liquid gaskets ?
10/08/2026
When it comes to sealing flanges, housings, and threaded joints in automotive, electronics, and industrial applications, two product families are commonly considered: RTV silicone sealants and non-silicone liquid gaskets . Both are applied as liquids and cure in place to create a reliable seal, but they are based on different chemistries and offer distinct performance characteristics.
Choosing between these solutions is not always straightforward. While they may appear to serve the same purpose, each technology has its own strengths, limitations, and ideal applications. Understanding the differences between RTV silicones and non-silicone liquid gaskets is therefore an essential step when selecting the most suitable sealing solution for a new design, manufacturing process, or maintenance operation.
In this article, we'll explore how these technologies differ, where each performs best, and the key factors to consider before making your choice.
Choosing between these solutions is not always straightforward. While they may appear to serve the same purpose, each technology has its own strengths, limitations, and ideal applications. Understanding the differences between RTV silicones and non-silicone liquid gaskets is therefore an essential step when selecting the most suitable sealing solution for a new design, manufacturing process, or maintenance operation.
In this article, we'll explore how these technologies differ, where each performs best, and the key factors to consider before making your choice.
01. What Are RTV Silicones and Liquid Gaskets?
Before comparing them, let's first define each technology.
RTV silicones are widely used as Formed-In-Place Gaskets (FIPG), replacing conventional pre-cut gaskets in many automotive and industrial assemblies.
A Formed-In-Place Gasket (FIPG) is a liquid sealing material dispensed directly onto a flange or mating surface before assembly. The material cures in place to form a custom-fit gasket that conforms perfectly to the geometry of the joint, eliminating the need for pre-cut gaskets while ensuring consistent sealing performance.
Although RTV silicones are technically a type of liquid gasket, this article uses the term "liquid gasket" to refer specifically to non-silicone liquid gasket technologies, such as the ThreeBond 1100 Series.
Like RTV silicones, they are applied directly onto the sealing surface before assembly, where they cure to fill microscopic surface imperfections and create a leak-tight seal. However, unlike RTV silicones, they generally provide higher oil and fuel resistance, lower permeability, and reduced contamination risk in sensitive systems. Depending on the formulation, some liquid gaskets remain flexible after curing, while others form a more rigid or semi-flexible seal designed for high-pressure or chemically aggressive environments.
Both RTV silicones and non-silicone liquid gaskets eliminate the need for conventional cut gaskets, but their curing mechanisms, mechanical properties, and chemical resistance make them suitable for different applications.
02.Advantages
| RTV Silicone | Liquid Gasket |
|---|---|
| Excellent flexibility and vibration absorption, even after full cure | Very thin bond line, ideal for precision-machined flanges and threaded joints |
| Strong resistance to heat, engine oils, coolants, and industrial chemicals | Many grades allow easy disassembly and rework, useful for parts requiring frequent maintenance |
| Available in several cure chemistries (oxime, acetone, alcohol) to suit different substrate sensitivities | Reduced material cost, since only a small amount is needed per joint |
| Ideal as a direct replacement for pre-cut gaskets (FIPG), simplifying assembly and reducing inventory | Wide range of chemistries available (non-drying, semi-drying, anaerobic) to match specific application needs |
| Good adhesion to a wide range of materials, including painted and oily surfaces (depending on grade) | Strong resistance to fuels and solvents in select grades |
| Excellent weathering and UV resistance | Excellent sealing performance with minimal gasket thickness |
03.Disadvantages
| RTV Silicone | Non-silicone liquid Gasket |
|---|---|
| Longer cure time compared to some anaerobic liquid gaskets, since curing depends on ambient humidity. | Some non-silicone grades offer less vibration damping than silicone rubber. |
| Excess uncured material (squeeze-out) can be messy and, in some formulations, may contaminate sensitive components (e.g., sensors) if not controlled. | Anaerobic types require close-fitting metal joints to cure properly and are less effective on porous or absorbent substrates. |
| Not all grades are suitable for surfaces that will be painted afterward. | Chemical and temperature resistance varies significantly by grade, making proper product selection essential. |
| Lower mechanical strength than some anaerobic sealants. | Some grades have limited gap-filling capability. |
04. Comparison table
| Criteria | RTV Silicone (ThreeBond 1200 Series) |
Non-silicone Liquid Gasket (ThreeBond 1100 Series) |
|---|---|---|
| Base chemistry | Silicone (oxime, acetone, or alcohol cure) | Synthetic resin, synthetic rubber, acrylate, anaerobic, and other non-silicone chemistries |
| Cure mechanism | Moisture-curing (atmospheric humidity) | Varies: non-drying, semi-drying, or anaerobic (absence of air) |
| Cured form | Flexible rubber elastomer | Thin elastic film or viscous sealing layer |
| Vibration absorption | Excellent | Moderate to good, depending on grade |
| Typical bond line | Thicker, gap-filling | Very thin |
| Disassembly | Possible, but can require more effort depending on grade | Often easier, especially with non-setting grades |
| Best suited for | Gaps and uneven surfaces, FIPG applications | Precision-machined flanges and threaded joints |
| Common use cases | Oil pans, valve covers, gearbox housings, ECU and electronic enclosures | Engine covers, pumps, compressors, hatch covers, threaded pipe connections |
How to Choose Between RTV Silicone and Liquid Gasket?
Choose RTV silicone when flexibility, vibration resistance, or gap-filling capability is required. Opt for a non-silicone liquid gasket when working with precision-machined flanges, threaded joints, or applications requiring a very thin sealing film and excellent fluid resistance.
05. Typical Applications
RTV silicone sealants are typically selected for applications requiring flexibility, vibration resistance, and accommodation of thermal expansion, including:
- Engine oil pans and valve covers
- Timing chain and transmission covers
- Gearbox and differential housings
- Water pumps and thermostat housings
- ECU, sensor, and electronic enclosure sealing
- EV battery pack covers and electrical housings
- Industrial machinery exposed to vibration and temperature cycling
- General Formed-In-Place Gasket (FIPG) applications replacing conventional cut gaskets
Available in several cure chemistries, including oxime, acetone, and alcohol-based formulations, the 1200 Series can be selected to meet specific substrate compatibility and manufacturing requirements. Designed for Formed-In-Place Gasket (FIPG) applications, these sealants effectively replace conventional pre-cut gaskets on engine and transmission components, electrical housings, battery enclosures, pumps, and a wide variety of industrial equipment.
Non-silicone liquid gaskets are generally preferred where a thin sealing film, excellent fluid resistance, or easy maintenance is required, including:
- Metal flange joints on engines, pumps, compressors, and gearboxes
- Threaded pipe fittings and hydraulic or pneumatic connections
- Fuel, oil, coolant, and pressurized fluid sealing
- Covers and inspection hatches requiring frequent disassembly
- Precision-machined flanges with very small gasket clearances
- Screw and threaded fastener sealing
- Battery components and electrolyte-resistant sealing (specific grades)
- Applications requiring low gasket thickness and controlled film formation rather than an elastic rubber gasket
Depending on the grade, the 1100 Series offers solutions ranging from non-setting compounds that facilitate easy maintenance and repeated disassembly to high-strength anaerobic sealants designed for permanent sealing under high pressure. Applied as a thin, uniform film, these products effectively fill surface imperfections while minimizing material consumption, helping manufacturers reduce waste and achieve reliable, long-lasting sealing performance.
Related pages
RTV silicone sealants and non-silicone liquid gaskets both provide reliable sealing solutions, but they are optimized for different requirements. RTV silicones excel where flexibility, vibration resistance, and gap-filling capabilities are essential, whereas non-silicone liquid gaskets are better suited to precision-machined joints, threaded connections, and applications requiring excellent fluid resistance or easy maintenance.
Ultimately, the right choice depends on the joint design, operating environment, service conditions, and assembly process. Selecting the appropriate chemistry will help maximize sealing performance, durability, and manufacturing efficiency.
| Selection Criteria | RTV Silicone (ThreeBond 1200 Series) |
Non-silicone Liquid Gasket (ThreeBond 1100 Series) |
|---|---|---|
| Flexible sealing | ✓ Excellent | ✓ Good (depending on grade) |
| Vibration resistance | ✓ Excellent | ✓ Good |
| Gap-filling capability | ✓ Excellent | ✗ Limited |
| Thin sealing film | ✓ Good | ✓ Excellent |
| Precision-machined flanges | ✓ Good | ✓ Excellent |
| Thread sealing | △ Possible (depending on grade) | ✓ Excellent |
| Easy disassembly | △ Depends on grade | ✓ Excellent (non-setting grades) |
| Oil resistance | ✓ Excellent | ✓ Excellent |
| Fuel resistance | ✓ Good | ✓ Excellent (selected grades) |
| High-temperature resistance | ✓ Excellent | ✓ Good (depending on grade) |
| Outdoor / UV resistance | ✓ Excellent | △ Depends on formulation |
| Best suited for | Uneven surfaces, vibration, FIPG applications | Precision flanges, threaded joints, maintenance applications |
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