LOCTITE EA 9394 AERO (Hysol EA 9394) epoxy paste adhesive EA 9394

Two-part amine-cured epoxy paste: a Part A epoxy resin with aluminium filler and a Part B amine hardener (composition ranges in story.recipe)

Also known as LOCTITE EA 9394 AERO, Hysol EA 9394, EA 9394

LOCTITE EA 9394 AERO, also known as Hysol EA 9394, is a two-part epoxy paste that cures at room temperature.

8 sources · Updated 2026-11-01 · CC BY 4.0

Evidence level

3 of 5

Space-relevant tests

Service temperature

177 °C

Strength at room temperature

28.9 MPa lap shear at 25 °C

Working time

Pot life 90 min at 25 °C

Outgassing

1.71 %

Recipe, share of the weight

  • Al 30 to 60%Aluminum (Part A)
  • 30 to 60%Tetraglycidyl diaminodiphenylmethane (Part A)
  • 10 to 30%Epichlorohydrin-4,4'-isopropylidene diphenol resin (Part A)
  • 5 to 10%Modified epoxy resin (Part A)
  • 1 to 5%Treated fumed silica (Part A)
  • 30 to 60%Tetraethylene pentamine (Part B)
  • 30 to 60%N,N'-Bis(3-aminopropyl)piperazine (Part B)
  • 5 to 10%3,6,9,12-Tetraazatetradecamethylenediamine (Part B)
  • 1 to 5%3,6-Diazaoctanethylenediamine (Part B)
  • C 0.1 to 1%Carbon black (Part B)

Best for

Room-temperature structural bonding, potting and liquid shims where a 177 °C (350 °F) service temperature is needed, per Henkel

Weakest at

Outgassing and heat: all eight EA 9394 rows read in NASA's listing are above 1.0 % total mass loss, and lap shear falls to 8.3 MPa at 177 °C

Risk at a glance

  • People High. Warning in Part A, danger in Part B
  • If it fails High. Uncontrolled heat build-up in a large mixed batch
  • Corrosion Moderate. The glass transition falls from 78 °C dry to 68 °C wet.

Quick facts: EA 9394

Key properties of EA 9394
PropertyValueBasis
Density1 to 1.5 g/cm³3 sourced values across conditions
Tensile strength46 MPa1 sourced value
Young's modulus4.24 GPa1 sourced value
Thermal conductivity0.33 W/(m·K)1 sourced value
Thermal expansion (CTE)55.6 ppm/K1 sourced value
Maximum service temperature177 °C1 sourced value

What is the density of LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive has a density of 1 to 1.5 g/cm³. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the thermal conductivity of LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive has a thermal conductivity of 0.33 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive has a coefficient of thermal expansion of 55.6 ppm/K. The source and test conditions are listed in the properties table on this page.

What is the tensile strength of LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive has a tensile strength of 46 MPa. The source and test conditions are listed in the properties table on this page.

What is the Young's modulus of LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive has a Young's modulus of 4.24 GPa. The source and test conditions are listed in the properties table on this page.

What are the other names and codes for LOCTITE EA 9394 AERO epoxy paste adhesive?

LOCTITE EA 9394 AERO epoxy paste adhesive is also written as LOCTITE EA 9394 AERO, Hysol EA 9394, EA 9394. Each code is printed in the source listed beside it in the designations table.

What is LOCTITE EA 9394 AERO epoxy paste adhesive used for?

Uses recorded in the sources include Structural bonding of aerospace aluminium parts; Potting, filling and liquid shims.

Why it exists

LOCTITE EA 9394 AERO, also known as Hysol EA 9394, is a two-part epoxy paste that cures at room temperature. Henkel sells it for structural bonding, potting and liquid shims, and says it is qualified to MMM-A-132 Rev B. Its main strengths, as printed, are a lap shear strength of 28.9 MPa at 25 °C, a 177 °C service temperature and a 90 minute pot life for a 450 g mix. Its weak point for space hardware is outgassing: NASA's compilation lists every EA 9394 row read above the 1.0 % total mass loss screen.

Where it's used

Aerospace structural bonding

Henkel calls the paste a two-part structural adhesive for aerospace bonding that cures at room temperature. It is qualified to MMM-A-132 Rev B, Type I, Class 3, Form 3, Group 1.

Potting, filling and liquid shims

The bulletin also lists potting, filling and liquid shim work, and says the thixotropic paste fills gaps well.

Outgassing screening record

NASA's 1993 compilation includes EA 9394 rows in its adhesives listing, each with its own cure schedule. These are ground outgassing records, not a flight result.

Recipe

Two-part amine-cured epoxy paste: a Part A epoxy resin with aluminium filler and a Part B amine hardener (composition ranges in story.recipe)

LOCTITE EA 9394 AERO is a two-part paste. Part A is an epoxy resin with aluminium filler, and Part B is an amine hardener. Henkel's bulletin mixes them 100 parts Part A to 17 parts Part B by weight. The ranges below are per part, as printed in each safety data sheet, and the SDS says exact percentages may vary or are trade secret. Epoxy resins are reactive prepolymers with epoxide groups, and amine hardeners cross-link them into a network (Wikipedia, Epoxy).

What EA 9394 is made of
IngredientShare of the weightWhat it does
Aluminum (Part A) Al 30 to 60% Aluminium metal, listed as a hazardous component of Part A.
Tetraglycidyl diaminodiphenylmethane (Part A) 30 to 60% Multifunctional epoxy resin that reacts with the amine hardener.
Epichlorohydrin-4,4'-isopropylidene diphenol resin (Part A) 10 to 30% Epoxy resin named in the SDS transport section as a bisphenol-A epichlorohydrin resin.
Modified epoxy resin (Part A) 5 to 10% Second epoxy resin; the SDS gives no CAS number and names it as a phenol polymer with chloromethyl oxirane.
Treated fumed silica (Part A) 1 to 5% Silica filler listed as a hazardous component of Part A.
Tetraethylene pentamine (Part B) 30 to 60% Amine component of Part B. Amines add across epoxide groups to form a cross-linked network (Wikipedia, Epoxy).
N,N'-Bis(3-aminopropyl)piperazine (Part B) 30 to 60% Amine curing agent.
3,6,9,12-Tetraazatetradecamethylenediamine (Part B) 5 to 10% Polyamine curing agent.
3,6-Diazaoctanethylenediamine (Part B) 1 to 5% Amine curing agent.
Carbon black (Part B) C 0.1 to 1% Pigment that colours Part B.

Weight shares are as printed in the sources.

What it can do

Service temperature

177 °C

measured

Henkel rates the adhesive for 177 °C (350 °F) service, defined as the temperature at which it still holds 6.9 MPa (1000 psi) lap shear per ASTM D1002. Lap shear at 177 °C is printed as 8.3 MPa.

Strength at room temperature

28.9 MPa lap shear at 25 °C

Bare 2024-T3 aluminium lap joints cured 5 days at 25 °C printed 28.9 MPa (4,200 psi) lap shear per ASTM D1002.

Working time

Pot life 90 min at 25 °C

A 450 g mix stays usable for 90 minutes at 25 °C (ASTM D 2471). Henkel says not to mix more than 450 g at once.

Outgassing

1.71 %

measured

NASA's 1993 compilation lists total mass loss of 1.71 % and collected volatile condensable material of 0.04 % for one EA 9394 row (7 days at 25 °C). That is above the 1.0 % TML limit that the compilation uses for low-outgassing materials.

How it compares

LOCTITE EA 9394 AERO is not a low-outgassing adhesive on the data read here, because each of the eight EA 9394 rows in the NASA listing is above 1.0 % total mass loss. Its printed 177 °C service temperature is far above its dry glass transition of 78 °C, and the bulletin does not reconcile the two; lap shear is already 20.7 MPa at 82 °C. The compare table below uses density, service temperature and NASA total mass loss, the three benchmarks for which this product has values in the sources read.

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details.

Benchmarks
MeasurementEA 9394
Thermal behavior and safety
Thermal conductivityBracketed SI value as printed in the bulletin0.331 W/(m•K)
Lifetime and stability
Pot life, 450 g mass90 min5
Shelf life when stored below 25 °C1 year6
Total mass loss, EA 9394 row GSC17063 (7 days at 25 °C)1.71 %26
Collected volatile condensable material, EA 9394 row GSC170630.04 %27
Total mass loss, EA 9394 row GSC17085 (7 days at 25 °C)1.14 %28
Collected volatile condensable material, EA 9394 row GSC170850 %29
Physical and electrical
Density, mixed adhesive (Part A plus Part B by weight 100:17)1.36 g/ml1
Density, Part A (epoxy component)1.5 g/ml2
Density, Part B (amine hardener)1 g/ml3
Shore D hardness88 Shore D18
Temperature behavior
Glass transition temperature, dry78 °C19
Glass transition temperature, wet68 °C20
Other measurements
Viscosity, mixed adhesive at 25 °C160 Pa·s4
Service temperature (1000 psi lap shear retained)177 °C7
Tensile lap shear strength at -55 °C22.7 MPa8
Tensile lap shear strength at 25 °C28.9 MPa9
Tensile lap shear strength at 82 °C20.7 MPa10
Tensile lap shear strength at 177 °C8.3 MPa11
Tensile lap shear strength at 204 °C4.1 MPa12
Tensile strength, bulk casting46 MPa13
Tensile modulus, bulk casting4237 MPa14
Shear modulus, dry1461 MPa15
Shear modulus, wet1027 MPa16
Elongation at break, bulk casting1.66 %17
Compressive strength, bulk casting68.9 MPa21
Dielectric constant at 1.0 kHz7.51 -22
Dissipation factor at 1.0 kHz0.022 -23
Coefficient of thermal expansion at 40 °C55.6 µm/m°C24
Coefficient of thermal expansion at 100 °C80.6 µm/m°C25

Why choose it, and why not

Good for

  • Structural bonding of aluminium at room temperature, with 28.9 MPa lap shear at 25 °C (ASTM D1002, 2024-T3 adherends).
  • Joints that must hold at 177 °C (350 °F), per the Henkel service-temperature definition.
  • Potting and liquid shim work, given its 90 minute pot life and gap-filling paste.

Watch out for

  • Outgassing: every EA 9394 row read in NASA's listing is above 1.0 % total mass loss, from 1.02 % to 1.74 %.
  • Heat: lap shear is 8.3 MPa at 177 °C and 4.1 MPa at 204 °C.
  • Moisture: the glass transition is 78 °C dry and 68 °C wet, which is below the 177 °C service temperature.
  • No flight or thermal-vacuum result for this adhesive was found in the sources read.

LOCTITE EA 9394 AERO is a well-documented room-temperature structural epoxy with 28.9 MPa lap shear at 25 °C and a Henkel-stated 177 °C service temperature. NASA's outgassing rows for it sit above the 1.0 % screen, so on these sources it is not a low-outgassing choice.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Other names and standards

The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.

Other names and standards
SystemCodes
Trade nameLOCTITE EA 9394 AERO, Hysol EA 9394, EA 9394

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Density, mixed adhesive (Part A plus Part B by weight 100:17)Typical value printed in the Uncured Properties table of the Henkel bulletinstate mixed two-part pastetemperature not printed in the bulletin—
2Density, Part A (epoxy component)Typical value printed in the Uncured Properties table of the Henkel bulletinstate Part A, uncuredtemperature not printed in the bulletinThe Part A SDS (Revision 006.3) prints relative density 1.49 with no unit or temperature. The bulletin value is kept here; the SDS value is not recorded as a property.
3Density, Part B (amine hardener)Typical value printed in the Uncured Properties table of the Henkel bulletinstate Part B, uncuredtemperature not printed in the bulletinThe Part B SDS (Revision 005.2) prints density 1.0 with no unit or temperature. The bulletin value is kept here.
4Viscosity, mixed adhesive at 25 °CBrookfield HBT typical value as printed in the bulletintemperature 25 °Cspindle Brookfield HBT Spdl 5 at 2.09 rad/sstate mixed two-part pasteThe same table gives 400 to 800 Pa·s for Part A and 20 to 70 Pa·s for Part B at 25 °C. The Part A SDS prints 400,000 to 800,000 mPa·s, which matches.
5Pot life, 450 g massTypical value printed in the Handling section of the bulletintemperature 25 °C (75 °F)mass 450 gmethod as printed ASTM D 2471 in water bath—
6Shelf life when stored below 25 °CTypical value printed in the Uncured Properties tablestorage below 25 °C (77 °F)—
7Service temperature (1000 psi lap shear retained)Service temperature definition as printed in the bulletindefinition temperature at which the adhesive still retains 1000 psi (6.9 MPa) tensile lap shear strength, ASTM D1002printed as 350 °F—
8Tensile lap shear strength at -55 °CTypical result printed in the bulletin (3,300 psi printed alongside)test temperature -67 °F / -55 °Ccure 5 days at 25 °Cstandard ASTM D1002adherends 2024-T3 bare aluminium, phosphoric acid anodized per ASTM D3933—
9Tensile lap shear strength at 25 °CTypical result printed in the bulletin (4,200 psi printed alongside)test temperature 77 °F / 25 °Ccure 5 days at 25 °Cstandard ASTM D1002adherends 2024-T3 bare aluminium, phosphoric acid anodized per ASTM D3933—
10Tensile lap shear strength at 82 °CTypical result printed in the bulletin (3,000 psi printed alongside)test temperature 180 °F / 82 °Ccure 5 days at 25 °Cstandard ASTM D1002adherends 2024-T3 bare aluminium, phosphoric acid anodized per ASTM D3933—
11Tensile lap shear strength at 177 °CTypical result printed in the bulletin (1,200 psi printed alongside)test temperature 350 °F / 177 °Ccure 5 days at 25 °Cstandard ASTM D1002adherends 2024-T3 bare aluminium, phosphoric acid anodized per ASTM D3933Above the 6.9 MPa (1000 psi) retention level that defines the 177 °C service temperature.
12Tensile lap shear strength at 204 °CTypical result printed in the bulletin (600 psi printed alongside)test temperature 400 °F / 204 °Ccure 5 days at 25 °Cstandard ASTM D1002adherends 2024-T3 bare aluminium, phosphoric acid anodized per ASTM D3933—
13Tensile strength, bulk castingTypical value printed in the bulletin (6,675 psi printed alongside)form 0.125 in (3.18 mm) bulk castingstemperature 25 °C (77 °F)standard ASTM D638—
14Tensile modulus, bulk castingTypical value printed in the bulletin (615 ksi printed alongside)form 0.125 in (3.18 mm) bulk castingstemperature 25 °C (77 °F)standard ASTM D638—
15Shear modulus, dryTypical value printed in the bulletin; test standard not printed (212 ksi printed alongside)condition drytemperature 25 °C (77 °F)—
16Shear modulus, wetTypical value printed in the bulletin; test standard and wetting method not printed (149 ksi printed alongside)condition wettemperature 25 °C (77 °F)—
17Elongation at break, bulk castingTypical value printed in the tensile-properties block of the bulletintemperature 25 °C (77 °F)—
18Shore D hardnessTypical value printed in the bulletin; test standard not printedtemperature 25 °C (77 °F)—
19Glass transition temperature, dryTypical value printed in the bulletin; test method not printed (172 °F printed alongside)condition dry—
20Glass transition temperature, wetTypical value printed in the bulletin; test method and wetting method not printed (154 °F printed alongside)condition wet—
21Compressive strength, bulk castingTypical value printed in the bulletin (10,000 psi printed alongside)temperature 25 °C (77 °F)specimen 0.5 in (12.7 mm) wide, 1.0 in (25.4 mm) long, 0.5 in (12.7 mm) highstandard ASTM D695—
22Dielectric constant at 1.0 kHzTypical value printed in the Electrical Properties table of the bulletinfrequency 1.0 kHzstandards as printed ASTM D149, D150—
23Dissipation factor at 1.0 kHzTypical value printed in the Electrical Properties table of the bulletinfrequency 1.0 kHzstandards as printed ASTM D149, D150—
24Coefficient of thermal expansion at 40 °CValue printed in the bulletin; test standard not printedtemperature 40 °C—
25Coefficient of thermal expansion at 100 °CValue printed in the bulletin; test standard not printedtemperature 100 °C—
26Total mass loss, EA 9394 row GSC17063 (7 days at 25 °C)Value listed in NASA RP-1124 Rev 3, Section I (Adhesives)data reference GSC17063cure 7 days at 25 °Catmosphere as printed AIRstandard ASTM E595 (TML), as described in the compilation introductionAbove the 1.0 % TML level that the compilation uses to define low-outgassing materials. Other EA 9394 rows in the same listing give 1.02 to 1.74 %.
27Collected volatile condensable material, EA 9394 row GSC17063Value listed in NASA RP-1124 Rev 3, Section I (Adhesives)data reference GSC17063cure 7 days at 25 °Catmosphere as printed AIRstandard ASTM E595 (CVCM), as described in the compilation introduction—
28Total mass loss, EA 9394 row GSC17085 (7 days at 25 °C)Value listed in NASA RP-1124 Rev 3, Section I (Adhesives)data reference GSC17085cure 7 days at 25 °Catmosphere as printed AIRstandard ASTM E595 (TML), as described in the compilation introductionStill above the 1.0 % TML level. The second row for the same product gives 1.71 % (GSC17063), so the two rows disagree; both are kept.
29Collected volatile condensable material, EA 9394 row GSC17085Value listed as 0.00 in NASA RP-1124 Rev 3, Section I (Adhesives)data reference GSC17085cure 7 days at 25 °Catmosphere as printed AIRstandard ASTM E595 (CVCM), as described in the compilation introduction—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Water, isopropyl alcohol, hydraulic oil and JP-4 fuel, 7 days at 25 °C low Lap shear strength stayed at 27.6 to 28.9 MPa after 7 days in four fluids, against 29.6 MPa for the unexposed control.1
Humid air during a long open time in large assemblies not rated Henkel recommends precautions against carbonate formation in large, humid assemblies left open for a long time.2
Moisture absorbed by the cured resin moderate The glass transition falls from 78 °C dry to 68 °C wet.3
Elevated temperature in service moderate Lap shear strength falls from 28.9 MPa at 25 °C to 8.3 MPa at 177 °C and 4.1 MPa at 204 °C.4
Corrosion details
#EnvironmentDetailsTest conditions
1 Water, isopropyl alcohol, hydraulic oil and JP-4 fuel, 7 days at 25 °C Henkel printed lap shear strengths of 28.2 MPa after water, 27.6 MPa after isopropyl alcohol, 28.2 MPa after hydraulic oil and 28.9 MPa after JP-4 fuel, each after 7 days at 25 °C, against 29.6 MPa for the room-temperature control. The bulletin gives no pass or fail limit, so the rating is an assistant judgement from these printed values. test tensile lap shear, ASTM D1002, 2024-T3 aluminiumexposure 7 days at 25 °C (77 °F)
2 Humid air during a long open time in large assemblies The bulletin says special precautions are recommended to minimize carbonate formation in large assemblies subject to extended open times in humid environments, and that Henkel can supply a memo with suggestions on request. The bulletin prints no amount of carbonate and no test result. basis statement only, no test data in the bulletin
3 Moisture absorbed by the cured resin The bulletin prints a glass transition of 78 °C dry and 68 °C wet, and a shear modulus of 1461 MPa dry against 1027 MPa wet, both at 25 °C. It does not say how the wet condition was reached or for how long. basis bulk casting; test method and wetting method not printed
4 Elevated temperature in service Printed lap shear values are 28.9 MPa at 25 °C, 20.7 MPa at 82 °C, 8.3 MPa at 177 °C and 4.1 MPa at 204 °C, after a 5-day cure at 25 °C and tested per ASTM D1002. Henkel defines the 177 °C service temperature as the point where lap shear is still 6.9 MPa (1000 psi). basis tensile lap shear, ASTM D1002, 2024-T3 aluminium with phosphoric acid anodize per ASTM D3933

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

Part A irritates and can sensitize the skin. Part B is corrosive and harmful if swallowed, according to the two safety data sheets.

Part A
Hazard statements H315, H317 and H319, under the WARNING signal word (SDS Revision 006.3).
Part B
Hazard statements H302, H314 and H317, under the DANGER signal word (SDS Revision 005.2).
Mixing
Batches above 450 g can overheat and give off toxic fumes, according to the bulletin. Mix smaller quantities.

If it is used hot or wet

Strength and glass transition both fall as temperature and moisture rise.

Heat
Lap shear strength is 8.3 MPa at 177 °C and 4.1 MPa at 204 °C, against 28.9 MPa at 25 °C.
Moisture
The glass transition is 78 °C when dry and 68 °C when wet, and the shear modulus is 1027 MPa wet against 1461 MPa dry.

In vacuum

The NASA compilation lists every EA 9394 row read above the 1.0 % total mass loss level that it uses for low-outgassing materials.

Total mass loss
1.71 % (7 days at 25 °C, row GSC17063) and 1.14 % (row GSC17085), with other rows between 1.02 % and 1.74 %.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Uncontrolled heat build-up in a large mixed batchhigh severityMixing more than 450 g of Part A and Part B in one batchDangerous heat buildup can occur, causing uncontrolled decomposition of the mixed adhesive and toxic fumes, which can cause personal injury, according to the bulletin.
Adhesive cures in the static mixer and blocks the cartridgemoderate severityLeaving the mixed adhesive in the static mixer unattended for more than 90 minutes, or applying high pressure to an overheated cartridgeCuring in the mixer produces back pressure when the plungers are triggered again, which can cause cartridge failure. The bulletin also reports 200 ml kit failures when inlet pressure is set too high.
Loading the joint before full curemoderate severityApplying load at the 24-hour handling pointFull bond strength is not yet attained at handling strength, so the bulletin says load application should be small at this time.

Side effects on surrounding parts

Side effects on surrounding parts
AffectsEffect
People in the fire area and the enclosureOn decomposition, both parts emit carbon monoxide, carbon dioxide, low molecular weight hydrocarbons and oxides of nitrogen, according to their safety data sheets.

Handling and storage

  • Keep Part A in a tightly closed container in a cool, well-ventilated place, away from incompatible materials (strong acids, oxidizing agents and amines). Part B is kept away from strong oxidizing agents and strong Lewis or mineral acids.
  • Use with adequate ventilation. Avoid getting it in eyes or on skin and avoid breathing vapors, and wash thoroughly after handling, per the bulletin's precautionary information. The bulletin says the material is for industrial use only.

Mitigations

  • Do not mix more than 450 g at once, and mix smaller quantities to minimize heat buildup, per the bulletin.
  • Do not pre-heat dual-cartridge kits above 90 °F for more than four hours, and do not place assembled cartridges upright in the oven.

Supply and geography

How common the raw materials are and where they come from.

LOCTITE EA 9394 AERO (Henkel Corporation product)

Not applicable: a formulated two-part product, not an element. No feedstock tonnage for epoxy resin or amine hardener was found in any source read.

Top producers
United States
Recycling
Not found in any source read.

Aluminium, the metal in the Part A filler

USGS smelter production in 2025, estimated, in thousand metric tons: China 45,000; United States 660; world total 74,000. The Part A SDS lists aluminum as a hazardous component, so the metal is part of this product.

Top producers
China, United States
Recycling
USGS: about 3.6 million tons of aluminum was recovered from purchased scrap in the United States in 2025, about 56% from new scrap and 44% from old scrap.

Updated