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3M™ Aerospace Sealant AC-380 Class B are fast cure, 1.1 specific gravity, solvent free, low shrinkage, and high temperature integral fuel tank sealants. This material is designed for fillet sealing of fuel tanks and other aircraft fuselage sealing applications. It offers as much as thirty percent weight savings, per unit volume, over traditional sealants with similar purpose. The cured sealants have outstanding resistance to aviation gasoline and jet fuel, as well as resistance to chemicals and petroleum products common to the aircraft industry. The sealants will resist limited contact to diphosphate ester based hydraulic fluid.
Unit of Measure

Typical Physical and Application Properties

Base Color

 N/A Off-White

Accelerator Color

 N/A Black

Mix Ratio (By Weight)

 N/A 100 Base/10 Catalyst

Non-Volatile Content

 N/A 97 %
Base Viscosity1 N/A 10,000 to 14,000 Poise

Note for Typical Physical and Application Properties

 N/A The technical information and data should be considered representative or typical only and should not be used for specification purposes.

Application Life and Cure Time at 77 Degree Fahrenheit (ºF) and 50 Percent (%) Relative Humidity

Class

 N/A B-1/2 B-2

Minimum Application Life for Class B-1/2

 N/A 1/2 hour

Minimum Application Life for Class B-2

 N/A 2 hour

Note for Minimum Application Life

 N/A Application life refers to the length of time that mixed compound remains at a consistency suitable for application with spatula or caulking gun. Application life is always measured at a standard temperature of 77 ºF with a relative humidity level of 50 %. In general, for every 20º rise in temperature, the application life is halved; for every 20º drop, it is doubled.

Typical Tack-Free Time for Class B-1/2

 N/A 5 hour

Typical Tack-Free Time for Class B-2

 N/A 8 to 10 hour

Note for Typical Tack-Free Time

 N/A Tack-free time is the length of time after which a mixed sealant will no longer tightly adhere to L-LP-690 standard low density polyethylene film.

Typical Cure Time for Class B-1/2

 N/A 5 hour

Typical Cure Time for Class B-2

 N/A 8 to 10 hour

Note for Typical Cure Time

 N/A Cure time is defined as the length of time it takes 3M™ Aerospace Sealant AC-370 Class B to reach 30 A hardness. It depends on three factors: remaining application life, temperature, and relative humidity. The temperature/humidity factors for application life also apply to curing. High humidity during cure will speed up the cure. To accelerate the curing process, apply heat up to (but not more than) 120 ºF .

Typical Physical and Performance Properties of Cured Compound after 14 Days at 77 Degree Fahrenheit (ºF)/50 Percent (%) Relative Humidity (Tested Per AMS3281)

Mixed Color

 N/A Dark Gray

Maximum Specific Gravity

 N/A 1.1

Hardness

 N/A 45 to 50 Shore "A"

Low Temperature Flexibility

 N/A No checking or adhesion loss when tested at -80 ºF (-62 ºC)

Service Temperature

 N/A -62 to +121 ºC-80 to +250 ºF

Short Term Service Temperature

 N/A -62 to +182 ºC-80 to +360 ºF

Thermal Rupture Resistance at 300 Degree Fahrenheit (ºF) Temperature and 30 Minutes (min) Time

 N/A Conforms

Thermal Rupture Resistance at 320 Degree Fahrenheit (ºF) Temperature and 30 Minutes (min) Time

 N/A Conforms

Weight Loss in Fuel after Drying

 N/A 4.2 %

Volume Swell in Josef Rakich Fitness (JRF) 7 Days at 140 Degree Fahrenheit (ºF) Temperature

 N/A 8 %

Corrosion

 N/A None
Repairability2 N/A 47 piw/100% Cohesive Failure

Repairability to Other Aerospace Material Specification (AMS3281) Sealants

 N/A 44 piw/100% Cohesive Failure

Repairability to Aerospace Material Specification (AMS3276) Sealants

 N/A 54 piw/100% Cohesive Failure

Specifications

Industry Focus

 N/A Aerospace

Relative Humidity

 N/A 50 %

Applications

 N/A Repairing Integral Fuel Tanks Sealing Fuselages Sealing Integral Fuel Tanks

Substrate Material

 N/A Aluminum Stainless Steel Steel Titanium

Material

 N/A Polysulfide

Health and Safety Precaution

Health and Safety Precaution

 N/A 3M™ Aerospace Sealant AC-380 Class B are safe to use and apply when recommended precautions are followed. Before using this product, read and understand the Material Safety Data Sheet (MSDS), which provides information on health, physical and environmental hazards, handling precautions and first aid recommendations. An MSDS is available on request.

Storage

Storage

 N/A The shelf life of 3M™ Aerospace Sealant AC-380 Class B is 9 months from date of packaging, when stored at temperatures below 80ºF in its original unopened container.

Technical Information

Technical Information

 N/A The technical information, recommendations and other statements contained in this document are based upon tests or experience that 3M™ believes are reliable, but the accuracy or completeness of such information is not guaranteed.

Product Use

Product Use

 N/A Many factors beyond 3M™'s control and uniquely within user's knowledge and control can affect the use and performance of a 3M™ product in a particular application. Given the variety of factors that can affect the use and performance of a 3M™ product, user is solely responsible for evaluating the 3M™ product and determining whether it is fit for a particular purpose and suitable for user's method of application.

Warranty, Limited Remedy, and Disclaimer

Warranty, Limited Remedy, and Disclaimer

 N/A Many factors beyond 3M™'s control and uniquely within user's knowledge and control can affect the use and performance of a 3M™ product in a particular application. Given the variety of factors that can affect the use and performance of a 3M™ product, user is solely responsible for evaluating the 3M™ product and determining whether it is fit for a particular purpose and suitable for user's method of application.

Limitation of Liability

Limitation of Liability

 N/A Except where prohibited by law, 3M™ will not be liable for any loss or damage arising from the 3M™ product, whether direct, indirect, special, incidental or consequential, regardless of the legal theory asserted, including warranty, contract, negligence or strict liability.

Additional Information

Additional Information

 N/A 3M™ AC-380 Class B Sealants are two-part, manganese dioxide cured, polysulfide polymer based sealants that maintain flexibility and bond strength on most metal substrates such as aluminum, titanium, steel, stainless steel, common composites and many coatings under extremes of temperature, weathering and stress. The mixed compound is a thixotropic paste easily applied by extrusion, injection gun or spatula, and exhibits superb tooling properties.

Note

Note

 N/A These products were manufactured under a 3M™ Quality Management System registered to the AS9100 standard.
  • 1 RVF Brookfield #7 spindle at 2 rpm, 77 ºF
  • 2 To Itself