Specialty Aerospace Adhesives: Epoxies, Retaining Compounds, and Anti-Seize for Aircraft Maintenance
Adhesives such as epoxies, retaining compounds, and anti-seize materials are among the most widely used consumables in aircraft maintenance. These are used throughout the aircraft and its components in just about every system. We help you stock these to prevent corrosion, repair equipment, and maintain operations.
Greenwood Aerospace is the trusted source for logistic support, supply, and consumable procurement in its own space. We have over 800 products on GSA Advantage to help you procure them in the fastest, easiest way possible, with hundreds of options. Let's take a look.
Critical Components Bonded by Adhesives
All aircraft rely heavily on adhesives for securing electrical assemblies, composite and metallic interfaces, and many other load-bearing components where mechanical fasteners are either impossible to use or insufficient. Sometimes they are also used to force-multiply the attachment between mechanical fasteners and a surface or component. High-risk interfaces usually include sensor housings, electrical potting cavities, bonded brackets, and secondary structural joints where high vibration and thermal cycling are common.
We recommend the following products for these functions:
- EA 9309 NA (EZ-PA packs) is commonly used for structural bonding in safety-critical assemblies, where predictable mix ratios and controlled curing are required.
- Loctite ABLESTIK CT 5047-2 is used to pot and encapsulate electrical components, protecting avionics and connectors from vibration, moisture ingress, and thermal stress.
High Temperature Performance Requirements
Certain areas of the aircraft are exposed to higher thermal cycling and temperature extremes than others. Specialty adhesives, epoxies, and thread lockers must be used in these circumstances to ensure the job they are intended to perform is done correctly and reliably.
- Structural epoxies such as EA 9309 NA are selected to meet defined glass-transition temperature (Tg) thresholds and to maintain shear strength after prolonged thermal exposure.
- Electrical potting compounds like Loctite ABLESTIK CT 5047-2 must retain dielectric properties and dimensional stability at temperature while managing exotherm during cure.
Aviation Applications and Certification Needs
Aerospace-grade adhesives are manufactured and chemically designed by engineers to work at a higher level than standard-grade epoxies and adhesives, because the tolerances are far different. Also, they have to meet certain guidelines by governing bodies, OEM manufacturers, military organizations, federal agencies, and so on.
Structure and potting epoxies are mapped to aircraft subsystems per OEM specs, including Boeing material specifications, AMS standards, MIL-PRF and MIL-SPEC, and other military standards.
Application Workflow for Aviation Applications
A controlled application process is crucial to achieving repeatable and reliable results. Here are the standardized workflows for adhesives and sealants:
1. Surface preparations first. This includes cleaning, abrasion, and solvent wiping. And these directly impact bond strength and long-term performance. We cannot overstate how important this is, and we carry a number of surface preparation products for you.
2. Cure verification checkpoints. This is to make sure epoxies like EA9309NA reach their full mechanical strength before a load is applied.
3. Torque checks. These are scheduled after cure when retaining compounds or NIC's products are used for threaded assemblies. This is to make sure they hold within the torque values they are supposed to hold.
Retaining Compounds for Cylindrical Parts
Retaining compounds are commonly used to secure cylindrical components such as bearings, bushings, and shafts where mechanical locking features are impractical. These anaerobic adhesives help fill microscopic gaps between metal surfaces and prevent fretting and movement under loads.
We recommend Loctite 620 Retaining Compound, designed for high-temperature environments and widely used in engine and engine-adjacent repairs, as well as landing gear applications. It has high resistance to thermal degradation, allowing it to maintain strong holding power under the most demanding conditions.
Retaining Compound Selection Criteria
So, how do you choose the right retaining compound? Selecting a retaining compound involves more than just the maximum strength value. Here are a few of the key considerations when you're purchasing retaining compounds:
• The required shear and compressive strength under operating loads
• The maximum continuous and intermittent temperature ratings
• How often is planned disassembly during overhaul or inspection cycles
High-temperature-rated compounds, namely Loctite 620, balance secure retention with controlled serviceability and support both reliability and maintainability. Loctite 620 resists loosening and increases friction, yet still allows you to disassemble parts.
Anti-Seize Matter That Prevents Galling
Anti-seize compounds prevent galling, seizing, and thread damage in high-load and high-temperature fasteners. These materials are important for engine hardware, exhaust systems, and other assemblies prone to corrosion or thermal expansion. We will double down on exhaust systems. These are among the most corrosive environments for aircraft or any equipment, so having the right compounds that resist corrosion is extremely important.
Our recommendation is Acheson L-GP 460 Anti-Seize. This is specially formulated to withstand extreme temperatures and maintain consistent viscosity, making it ideal for engine components.
Compatibility With Epoxies and Other Sealants
Anti-seize materials cannot contaminate bonding surfaces. Even small amounts can and will compromise epoxy adhesion. These are not compatible materials, and they have completely different chemical compositions. Compatibility testing makes sure that products like Acheson L-GP460 do not migrate into adjacent parts and bonding joints. Primer systems and strict masking procedures are recommended when applying epoxies such as EA9309NA or Loctite ABLESTIK CT 5047-2 near threaded hardware.
Application Best Practices
The specifics of the application must be obtained from the product's instructions. However, there are common best practices that work for most products. These usually include:
• Cleaning substrates to a specified cleanliness level
• Applying epoxies uniformly within open time limits
• Assembling components within fixture windows
• Verifying cure by using hardness peel or electrical tests
Maintenance programs should include a local documentation process for reapplication intervals, inspecting fasteners for galling before reassembly, and applying anti-seize to designated hardware.
Safety, Storage, and Handling
Safety, storage, and handling are always important factors in all chemicals used in aircraft maintenance. While there are general best practices, you should consult the safety data sheet for each product type to see exactly what it needs.
Here are a few of the common storage and handling best practices, though:
- Store all materials within manufacturer-specified temperature ranges
- Maintain SDS availability for epoxies, retaining compounds, and anti-seize products
- Dispose of waste materials in accordance with environmental regulations
Product Selection and Procurement
Procurement teams will benefit from a side-by-side product comparison. These will include OEM part numbers, temperature limits, and the typical applications and cure or handling requirements for these items. Bear in mind that what we've talked about in this article is not necessarily interchangeable. But the process of ensuring you have compliant, efficient sourcing remains the same.
This applies to EA 9309 NA, Loctite ABLESTIK CT 5047-2, Loctite 620, and Acheson L-GP 460 alike.
Here is a convenient table to review which of these products works best for you:
Procurement Through Greenwood Aerospace
Greenwood Aerospace is your preferred partner for sourcing all kinds of aircraft maintenance and repair consumables, from hydraulic fluids and turbine engine oils to sealants, fasteners, adhesives, and epoxies. We also carry paint and primers, and surface preparation items. If we don't already have what you're looking for listed on GSA Advantage, contact our team, and we can probably procure whatever you need.
ITAR-registered and AS9120B-certified, Greenwood Aerospace supports defense contractors with compliant export solutions for military programs.
GSA Contract Number: 47QSMS25D00B8
UEI: KVSUYYSJS174 · DUNS: 604006874 · Cage Code: 2Y735
ITAR DDTC Export Compliant · NAICS: 488190, 336413, 332722, 336411, 481212, 532411
Availability, expedited shipping, or large orders? Contact us at: gsasales@greenwood.aero | 580-865-6000 | 833-GSA-EBUY
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