SEALANTS

Aircraft Sealants for Aviation Maintenance

Aircraft sealants are essential maintenance materials used to prevent leaks, protect aircraft structures from moisture and corrosion, seal fuel tanks and fuselage joints, and provide environmental protection throughout the aircraft. Business Aircraft Consumables supplies aerospace sealants from established manufacturers including PPG, PPG/Pro-Seal, Flamemaster/Chemseal, and DOWSIL.

BAC's aircraft sealant selection includes fuel tank sealants, corrosion-inhibitive sealants, windshield and canopy sealants, access door sealants, firewall sealants, environmental sealants, electrical sealants, silicone sealants, and other specialty aerospace sealing compounds.

Aircraft sealants are formulated for demanding aviation environments where components may be exposed to fuel, hydraulic fluids, temperature extremes, pressure changes, vibration, moisture, and structural movement.

The correct sealant depends on the specific aircraft application, substrate, required specification, cure system, temperature range, fuel or chemical exposure, and application method. Sealants that appear similar are not necessarily interchangeable.  Review BAC's Aircraft Sealant Guide for more information.

When selecting an aircraft sealant, always verify the required product and specification against the applicable aircraft maintenance manual, engineering documentation, drawing, or manufacturer's specification.

Aircraft Sealants by Application

Aircraft Fuel Tank Sealants

Fuel tank sealants are among the most commonly used aerospace sealants. They are designed for sealing integral fuel tanks and related aircraft structures exposed to aviation fuels.

BAC stocks fuel tank sealants from PPG/Pro-Seal and Flamemaster/Chemseal in multiple classes, cure times, package sizes, and specifications. Products include Class A, Class B, rapid-cure, and low-weight fuel tank sealants.

Common aerospace specifications represented in BAC's catalog include AMS-S-8802, MIL-S-8802, AMS 3277, AMS 3281, and other aircraft sealant specifications. The exact specification, class, grade, and product configuration must be verified before use.

For fuel tank work, select the sealant specifically identified by the applicable aircraft maintenance or engineering documentation. Do not substitute a different sealant solely because it appears to meet a similar specification.

Aircraft Sealant Classes

Aircraft sealants are available in different classes and cure characteristics to accommodate different application methods and maintenance requirements.

Class designations are specification- and product-dependent. Always verify the manufacturer's technical data for the specific sealant before assuming a particular application method or cure characteristic.

Two-Part Aircraft Sealants

Many aerospace sealants are supplied as two-part systems consisting of a base compound and curing agent. The components may be supplied separately for mixing immediately before use or packaged in pre-measured systems.

BAC offers two-part aircraft sealants in formats including pints, Semkits, and other pre-measured packaging. Pre-measured packaging can be useful for smaller maintenance jobs where only a limited quantity of mixed sealant is required.

The required mix ratio, working time, application life, cure time, and storage conditions vary by product. Follow the manufacturer's current technical data for the specific sealant.

Aircraft Sealant Types

The properties above are general descriptions and do not establish suitability for a particular aircraft application. Always select the sealant based on the applicable specification and approved product.

Aircraft Sealant for Windshields and Canopies

Aircraft windshields, canopies, and transparent components require sealants specifically designed for the materials and operating conditions involved.

BAC carries aircraft windshield and canopy sealants, including PPG products such as PR1425 and PR1829. Depending on the product, these sealants may be designed for glass, polycarbonate, acrylic, or other specified substrates.

Before applying sealant around an aircraft transparency, verify substrate compatibility, surface preparation, primer requirements, application procedure, cure requirements, and the applicable aircraft maintenance documentation.

Corrosion-Inhibitive Aircraft Sealants

Corrosion-inhibitive sealants are designed to provide a sealing barrier that helps protect aircraft structures from moisture and corrosion. They can be particularly important in applications involving aluminum structures and dissimilar-metal interfaces.

BAC carries corrosion-inhibitive aircraft sealants including PPG PS870 and other application-specific products. The required product should be selected according to the aircraft manufacturer's approved specification and application instructions.

Aircraft Sealant Application Tools

Proper application equipment is an important part of aircraft sealant work. BAC supplies manual, pneumatic, and battery-powered sealant guns, along with cartridges, nozzles, retainers, and other dispensing accessories.

BAC stocks standard 2-inch and 4-inch dispensing nozzles as well as empty 2.5-ounce and 6-ounce cartridges for applicable applications. Specialty tips may also be available.

Aircraft Sealant Removal Tools

Removing old or damaged sealant is an important part of many aircraft sealing repairs. BAC carries non-metallic sealant scrapers and 3M sealant cutters designed for controlled removal of cured or unwanted sealant.

Non-metallic scrapers can be useful where technicians need to remove sealant or adhesive while minimizing the risk of scratching the underlying substrate. BAC also offers 3M SR sealant cutters designed for removal of cured aircraft sealant with compatible pneumatic equipment.

Use the appropriate removal tool and technique for the substrate and aircraft structure. Follow applicable maintenance instructions when removing existing sealant from aircraft components.

Aircraft Sealant Specifications and Cross Reference

Aerospace sealants are frequently specified by military, aerospace, OEM, or industry specifications. BAC maintains an Aircraft Sealant Cross Reference guide to help maintenance personnel identify products associated with commonly encountered specifications.

The cross-reference includes specifications and applications covering fuel tank sealants, firewall sealants, environmental sealants, electrical sealants, windshield sealants, access door sealants, corrosion-inhibitive sealants, and rapid-cure products.

A cross-reference is not an automatic substitution. Product qualification can depend on the specific manufacturer, product configuration, class, grade, cure system, and application. Always verify the current specification and approved product before making a substitution.

Aircraft Sealant Storage and Shelf Life

Aircraft sealants have product-specific storage and shelf-life requirements. Shelf life can vary significantly depending on the sealant chemistry, package configuration, storage temperature, manufacturer, and product.

Many aircraft sealants are date-sensitive materials. Before use, inspect the container for the manufacturer's expiration or shelf-life information and verify that the material remains within the applicable shelf-life requirements.  When in doubt, consult BAC's Shelf Life Calculator tool.

Store sealants according to the manufacturer's current instructions. Do not assume that the shelf life of one sealant applies to another sealant, even when the products have similar specifications or applications.

Choosing the Correct Aircraft Sealant

When selecting an aerospace sealant, verify the following:

• Application: Determine whether the sealant is being used for a fuel tank, access panel, windshield, fuselage joint, firewall, electrical system, or another application.
• Specification: Verify the exact MIL, AMS, OEM, or other required specification.
• Class and grade: Confirm the required sealant class, grade, cure system, and application characteristics.
• Substrate: Verify compatibility with the aircraft material and any existing coating or primer system.
• Cure characteristics: Consider application life, cure time, and required service conditions.
• Temperature: Confirm the required service temperature range for the application.
• Chemical exposure: Verify resistance to fuel, hydraulic fluid, oil, water, and other fluids relevant to the installation.
• Package size: Select the appropriate package or pre-measured kit for the quantity required.
• Shelf life: Confirm that the material is within its applicable shelf life before use.

Aircraft Sealants for MROs, FBOs, and Maintenance Departments

BAC supplies aircraft sealants and related application equipment for MRO facilities, FBOs, corporate flight departments, aircraft operators, manufacturers, government organizations, and aircraft maintenance departments.

Our sealant selection includes commonly used aerospace products as well as specialized and lower-volume materials. Some sealants are stocked while others may be available by special order because of limited demand or relatively short shelf life.

If you do not see the specific sealant, specification, class, or package you need, contact BAC to check availability and sourcing options.

Aircraft Sealant FAQ

Maintenance Note: Aircraft sealants are application-specific materials. Always verify the required sealant, specification, class, grade, cure system, substrate compatibility, and shelf life against the applicable aircraft maintenance manual, engineering documentation, drawing, or manufacturer's current technical data before use.