Adhesives and Sealants for Engine Applications
Whether maintaining a fleet of military vehicles or ships, servicing aircrafts and turbine engines, or keeping consumer cars on the road, reliable construction and maintenance of the engine is vital. Adhesives and sealants are used throughout engine systems from bonding the primary metal components to thread sealing and noise dampening. The choice of material can be the difference between mission success and passenger safety or a costly failure in the field or on the road.
Challenges of Engine Assembly and Maintenance
Engines face some of the most extreme environments, from water exposure in marine vessels, to mechanical stress in military jets, making reliable, efficient engine manufacturing an engineering challenge. Common challenges include:
- Exposure to oils, chemicals, hydraulic fluid, and fuel
- Constant vibration and mechanical stress
- Shock and impact risks
- Extreme temperatures and thermal cycling
- Corrosion
- Fluid leaks
- Industry specifications i.e. MiL Spec
- Moisture ingress in marine environments
Why use Adhesives in Engines?
Adhesives and sealants offer a wide range of advantages suitable for engine construction and maintenance which can’t always be achieved with mechanical alternatives. Some key benefits for using adhesives include:
- Help reduce noise, emissions and fuel consumption
- Reduce manufacturing time via automation and bulk dispensing
- Reduce material wastage and manual error in manufacturing
- Some grades allow for component assembly for repairs and maintenance
- Better accommodation for vibration and thermal expansion
- Thermal protection and wide operating temperature ranges
- Weather, UV and ozone resistance
- Different colours, grades, viscosities and industry specifications available
Adhesive Applications in Engines
Adhesives and sealants are used throughout engine construction primarily for gasketing, pipe sealing and metal component bonding. Other applications include:
- Electronics potting
- Sensor housing sealing
- Thermal management and cooling systems
- Gap filling
- Exhaust systems
- Noise dampening
- In the field repairs
Engine Suitable Adhesives and Sealants
There are multiple adhesive types suitable for different engine applications, some options available include RTV silicones, non-setting jointing compounds, and threadlockers.
RTV Silicones
Arguably the most popular sealing compound in engine applications, RTV silicones, or room temperature vulcanising silicones, are used for gasketing and sealing applications. They offer reliable performance over a vast temperature range, maintain flexibility after cure, and can withstand industrial oils.
RTV silicones are available with military specifications, aerospace specifications, UL approvals, and low outgassing properties, making them suitable for various industries including defence, aerospace MRO, and automotive.
Non-Setting Compounds
Non setting jointing compounds are paste products which never fully cure, making them ideal for disassembly and maintenance applications for critical components without risk of damage. They offer fuel resistance, a long service life without cracking and can be used to fill minor surface irregularities. These compounds tend to be used for general pipe thread sealing, fuel and oil system connections and other common applications.
Threadlockers
Available in various strengths thread locking adhesives fill gaps between threaded components, curing with the absence of air in tight spaces. The different strength options mean these adhesives can be used for components needing disassembly or provide permanent sealing. They help to prevent fasteners from loosening due to vibration or shock, prevent fluid leakages, and corrosion.
Products to Consider
Momentive RTV106 (MIL-A-46106B) – Silicone adhesive sealant with high temperature performance -60°C to +260°C.
Momentive RTV133 – Low flammability UL rated black silicone sealant for electronic applications
Momentive RTV142 – Low outgassing sealant for critical electronic adhesive, gasketing and sealing applications
Hylomar Aerograde - non-setting gasketing compound that has been highly engineered for use in the aeronautical industry.
Permabond 910 – Metal bonding cyanoacrylate with aerospace approval from Boeing
Permabond MH196 – High temperature resistant anaerobic adhesive for making “formed in situ” gaskets between metal surfaces.
Loctite 243 - Medium strength threadlocker with tolerance to minor oil contamination for locking and sealing fasteners.
For specialist applications from defence to aviation to marine Contact our Experts to ensure the right products are chosen with the necessary approvals and full technical support.