ARADUR 891

ARADUR 891 is a very low-viscosity, solvent-free formulated polyamidoamine epoxy hardener developed primarily for civil-engineering adhesive and coating systems, with current product positioning centered on tile adhesives. Current product-specific data give approximately 130-190 mPa·s viscosity at 25°C, an amine value of approximately 520-540 mg KOH/g, density around 0.94 g/cm³ at 20°C, flash point around 110°C by Pensky-Martens closed-cup testing and an approximately 100-minute gel time at 23°C using a 250 g ARALDITE GY 783 reference system. The optimum documented ARALDITE GY 783 / ARADUR 891 mix ratio is approximately 100:40 parts by weight. Older ambient-curing selector literature additionally gives an active-hydrogen equivalent weight of approximately 74-82 g/eq, Gardner color ≤10, benzyl-alcohol-free status and an approximately 100-minute selector gel time with ARALDITE GY 250. ARADUR 891 is distinguished by unusually low viscosity for a formulated polyamidoamine, very good processing behavior, water-washable uncured handling, good resistance to inorganic acids and suitability for bonding and joining tiles in wet-service and hygienic industrial environments.

PRODUCT IDENTITY

Product name: ARADUR 891
Product type: Epoxy curing agent / hardener
Chemical family: Polyamidoamine
Specific chemistry: Formulated polyamidoamine
Physical form: Liquid
Appearance: Clear liquid
Odor: Amine
Current viscosity at 25°C: Approximately 130-190 mPa·s
Current amine value: Approximately 520-540 mg KOH/g
Older selector amine-value range: Approximately 520-550 mg KOH/g
Historical / selector active hydrogen equivalent weight: Approximately 74-82 g/eq
Current density at 20°C: Approximately 0.94 g/cm³
Current flash point: Approximately 110°C by Pensky-Martens closed-cup testing
Current reference gel time: Approximately 100 minutes at 23°C using a 250 g ARALDITE GY 783 system
Older selector gel time: Approximately 100 minutes with ARALDITE GY 250 under the selector comparison method
Historical selector color: Gardner ≤10
Current primary product function: Hardener
Current primary product end use: Tile adhesive
Current principal feature: Solvent resistance
Current key processing feature: Solvent-free and very low viscosity
Current special handling feature: Uncured system can be washed down with water in the documented tile-adhesive system
Current optimum reference mix ratio: ARALDITE GY 783 / ARADUR 891 = approximately 100:40 parts by weight
Current documented resistance profile: Good resistance to inorganic acids, less good resistance to oxidizing acids and organic acids, and moderate resistance to solvents
Current low-temperature note: Cure slows below approximately 20°C
Current accelerator guidance: Small quantities of Accelerator 960-1 can be used to compensate for cure delay below approximately 20°C where validated
Historical selector application code: CE / Civil Engineering
Benzyl alcohol status: Older ambient-curing selector literature marks ARADUR 891 as benzyl-alcohol-free
Current inventory listings: AIIC, DSL, ENCS, IECSC, KECI, PICCS, TCSI and TSCA, subject to current regional confirmation
Current storage temperature: Approximately 2-40°C
Minimum storage temperature limitation: Storage temperature should not be allowed to drop below 0°C
Storage condition: Dry place, preferably sealed original container, protected from direct sunlight
CAS Number: Proprietary formulated polyamidoamine mixture; no single universal CAS number should be assigned to the complete trade grade without current SDS confirmation
EC Number: Proprietary commercial formulation; no single universal EC number should be assigned without current product-specific documentation
Molecular Formula: Not applicable to the complete commercial formulation
Molecular Weight: Variable / not applicable as one fixed value

Synonyms: ARADUR 891, Formulated Polyamidoamine, Polyamidoamine Epoxy Hardener, Polyamidoamine Curing Agent, Epoxy Hardener, Epoxy Curing Agent, Tile Adhesive Hardener, Civil-Engineering Epoxy Hardener, Low-Viscosity Epoxy Hardener, Solvent-Free Epoxy Hardener, Construction Adhesive Hardener, Tile-Bonding Epoxy Hardener, Mineral-Substrate Adhesive Hardener, Chemical-Resistant Epoxy Hardener, Water-Washable Epoxy Hardener, Ambient-Cure Epoxy Hardener

ARADUR 891 should be treated as a proprietary formulated polyamidoamine curing agent rather than as one pure molecular substance. The most useful technical identifiers are its low viscosity, high amine value, selector AHEW range, density, reference gel time, solvent-free character and documented tile-adhesive performance. Formal component identity, concentration ranges, hazard classification and transport status should be taken from the current product-specific SDS.

WHAT IS ARADUR 891?

ARADUR 891 is a low-viscosity liquid polyamidoamine hardener designed for two-component ambient-cure epoxy systems.
The grade is notable because its 130-190 mPa·s viscosity is exceptionally low for a formulated polyamidoamine and allows easy mixing and substrate wetting without relying on a conventional solvent carrier.
Current product positioning focuses on epoxy tile adhesives, especially systems based on ARALDITE GY 783.
The documented adhesive system is used for bonding and joining tiles in environments such as bathrooms, food-processing areas, dairies, breweries and beverage-filling facilities.
ARADUR 891 also belongs to the broader civil-engineering curing-agent family, where low viscosity, good inorganic-acid resistance and solvent-free processing are valuable.
Its approximately 100-minute current reference gel time provides much more application time than fast cycloaliphatic or mercaptan hardeners, making the grade practical for larger adhesive areas and construction work.

FORMULATED POLYAMIDOAMINE CHEMISTRY

Polyamidoamines are polymeric amine curing agents containing both amide and amine functionality.
They are commonly built from fatty-acid-derived or dimer-acid-related structures reacted with polyamine components, producing a flexible polymeric backbone that retains reactive amine hydrogens.
Formulation can reduce viscosity, improve compatibility, modify cure speed and optimize application performance relative to an unmodified polyamidoamine base.

ARADUR 891 is specifically described as a formulated polyamidoamine rather than a simple pure polyamine.
The amine functionality opens epoxy rings and becomes chemically incorporated into the thermoset network.
Because the commercial grade is proprietary and formulated, the exact molecular distribution should not be reduced to one invented structure or molecular weight.

HOW EPOXY CURING WORKS

Epoxy resins contain reactive oxirane rings.
Primary and secondary amine hydrogens in ARADUR 891 attack these rings and form carbon-nitrogen bonds together with hydroxyl groups.
Repeated reaction between multifunctional epoxy resin and multifunctional polyamidoamine creates a three-dimensional crosslinked thermoset network.
The mixed system first remains fluid enough for wetting, spreading and tile placement, then gradually increases in viscosity as molecular weight rises.
Gelation occurs when the growing network prevents bulk flow, but cure continues after gelation and final mechanical and chemical properties develop progressively.
The approximately 100-minute reference gel time therefore describes comparative reactivity rather than complete cure time.

VERY LOW VISCOSITY

Very low viscosity is one of the defining technical advantages of ARADUR 891.
Current product data give approximately 130-190 mPa·s at 25°C.
This viscosity is much lower than that of many conventional polyamidoamine hardeners and helps the resin-hardener blend wet tile backs, mineral substrates and fillers efficiently.
Low viscosity also supports solvent-free formulation because viscosity control does not require a large external solvent fraction.
In adhesive mortars and tile-bonding compounds, filler loading can be increased while maintaining practical mixing and application.
Vertical tile systems still require rheology control because a very fluid binder alone would allow sag or tile slip.

AMINE VALUE

Current product-specific data give ARADUR 891 an amine value of approximately 520-540 mg KOH/g.
Older selector literature gives a slightly wider historical range of approximately 520-550 mg KOH/g.
The current product-specific 520-540 mg KOH/g range should be treated as the primary present reference.
Amine value is a titration-based measure of basic nitrogen functionality expressed as equivalent potassium hydroxide.
The value is useful for product identity and incoming quality control.
Amine value should not be used in place of AHEW for precise stoichiometric calculation because total basic nitrogen functionality and reactive amine-hydrogen equivalents are not identical measurements.

ACTIVE HYDROGEN EQUIVALENT WEIGHT

Older selector literature gives ARADUR 891 an active-hydrogen equivalent weight range of approximately 74-82 g/eq.
AHEW represents the mass of hardener required to provide one equivalent of reactive amine hydrogen.
Using a resin EEW of 190 g/eq, this selector range gives a theoretical hardener demand of approximately 38.9-43.2 parts ARADUR 891 per 100 parts resin.
The midpoint of the selector range gives approximately 41.1 phr at resin EEW 190 g/eq.
This is close to the current documented ARALDITE GY 783 / ARADUR 891 mix ratio of 100:40 parts by weight.
The agreement supports the technical consistency of the current ratio, but current resin-specific recommendations should still take precedence over theoretical calculation.

CURRENT DENSITY

Current product-specific data give ARADUR 891 a density of approximately 0.94 g/cm³ at 20°C.
Density is useful for inventory control, process calculations and conversion between mass and volume.
Epoxy stoichiometry should preferably be controlled on a weight basis because density varies with temperature.
Volumetric dispensing equipment should be calibrated using actual product temperature and the current product density.
Density can also serve as a secondary incoming quality-control parameter when interpreted together with viscosity and amine value.

CURRENT FLASH POINT

Current product-specific data give ARADUR 891 a flash point of approximately 110°C by Pensky-Martens closed-cup testing.
The relatively high flash point is consistent with the product's solvent-free positioning.
A high flash point reduces flammability concerns compared with low-boiling solvent-cut curing-agent solutions but does not make the product non-combustible.
Heating, storage and fire response should therefore follow current SDS requirements.
The finished formulation can have a different flash point if solvent or other volatile components are introduced elsewhere in the system.

CURRENT GEL TIME WITH ARALDITE GY 783

Current product-specific information gives an approximately 100-minute gel time at 23°C using a 250 g ARALDITE GY 783 reference system.
This value is the primary present gel-time reference for ARADUR 891.
The relatively long gel time provides time for mixing, spreading, tile placement and alignment.
Practical working time may nevertheless be shorter than formal gel time because viscosity rises continuously as cure advances.
Large mixed batches can self-heat and react faster than the standardized reference mass.
Field pot life should therefore be established on the actual filled adhesive formulation and application temperature.

OLDER SELECTOR GEL TIME WITH ARALDITE GY 250

Older ambient-curing selector literature lists an approximately 100-minute gel time for ARADUR 891 using ARALDITE GY 250.
The fact that both the current GY 783 system and older GY 250 selector show approximately 100 minutes should not be interpreted as proof that all resin systems cure identically.
The test resin, batch mass, formulation details and documentation generation can differ.
Current product-specific GY 783 data should control present formulation guidance for the tile-adhesive system.
The older GY 250 result remains useful as comparative historical selector information.

ARALDITE GY 783 REFERENCE SYSTEM

ARALDITE GY 783 is the principal current reference resin for ARADUR 891.
The documented optimum mix ratio is approximately 100 parts ARALDITE GY 783 to 40 parts ARADUR 891 by weight.
The current gel time for this system is approximately 100 minutes at 23°C using a 250 g reference mass.
The resin-hardener combination is specifically used for bonding and joining tiles.
The system is particularly relevant where low mixed viscosity, mineral-surface wetting and solvent-free processing are required.
The complete adhesive formulation can also contain fillers, thixotropes, pigments and other additives that modify rheology and application behavior.

OPTIMUM MIX RATIO

The documented optimum ARALDITE GY 783 / ARADUR 891 mix ratio is approximately 100:40 parts by weight.
This ratio should be weighed accurately because off-stoichiometric cure can change hardness, chemical resistance and water sensitivity.
The 40 phr level also aligns reasonably with the 74-82 g/eq historical AHEW range and a conventional liquid-epoxy EEW.
The ratio should not be transferred automatically to a different epoxy resin because each resin has its own epoxy equivalent weight.
Reactive diluents also change effective EEW and therefore change the amount of hardener required.
Current product-specific system guidance should control production formulation.

SOLVENT-FREE CHARACTER

Current product-specific information describes ARADUR 891 as solvent-free.
This is particularly important in construction and tile-adhesive systems where high solids, low shrinkage and reduced volatile emissions are desirable.
Solvent-free hardener also allows formulators to build viscosity through resin and filler architecture rather than depending on evaporation of a carrier solvent.
The complete finished adhesive is not automatically VOC-free because other raw materials may introduce volatile substances.
Formal VOC claims should therefore be based on the entire formulation under the applicable regional definition.
From a process perspective, the key benefit is that ARADUR 891 itself does not require a conventional solvent carrier to remain fluid.

WATER-WASHABLE UNCURED HANDLING

Current product information states that the ARADUR 891 system can be washed down with water.
This is a useful processing advantage in tile-adhesive work because tools, surfaces and application equipment can be easier to clean before the epoxy cures fully.
The statement applies to uncured handling and should not be interpreted as evidence that the cured thermoset is water soluble.
Once the epoxy network is formed, the material is chemically crosslinked and cannot simply be washed away with water.
Cleanup should occur promptly because cure progressively reduces washability.
Wash water containing uncured epoxy components should be managed according to environmental and waste requirements rather than discharged uncontrolled.

TILE-ADHESIVE POSITIONING

Tile adhesive is the primary current product end use for ARADUR 891.
The documented ARALDITE GY 783 / ARADUR 891 system is used for bonding and joining tiles.
Epoxy tile adhesives are particularly useful where ordinary cementitious adhesive would not provide sufficient chemical resistance, bond strength or water resistance.
The low-viscosity hardener helps wet mineral tile surfaces and substrates while the filled formulation provides body and gap-filling capability.
The approximately 100-minute gel time provides enough working time for spreading, tile placement and adjustment.
The complete adhesive should be designed for sag resistance, open time, bond strength and chemical exposure.

APPLICATIONS

Tile adhesives
Tile adhesive is the primary current end use. ARADUR 891 is used with ARALDITE GY 783 in epoxy systems for bonding and joining tiles.

Bathroom tile bonding
The documented tile-adhesive system is relevant to bathrooms and wet interior areas where water resistance and durable adhesion are important.

Food-processing tile bonding
Tile systems in hygienic processing environments can benefit from chemical resistance, low porosity and easy cleaning of the cured epoxy joint.

Dairy-area tile bonding
Dairy processing areas are specifically included in the documented application examples for tile bonding.

Brewery tile bonding
Breweries are included among the documented tile-bonding environments, where repeated washing and chemical exposure can challenge ordinary adhesive systems.

Beverage-filling areas
Beverage-filling stations are specifically identified in the current application guidance for the ARALDITE GY 783 / ARADUR 891 system.

Slaughterhouse tile bonding
Hygienic industrial environments with frequent washing and cleaning can use chemically resistant epoxy tile adhesive where service conditions have been 
validated.

Industrial kitchen tiling
Commercial and industrial kitchens can use epoxy tile adhesive where water, grease and cleaning chemicals require durable bond performance.

Wet-room tile systems
Showers, washrooms and other wet-service areas can use compatible epoxy tile adhesive where substrate and waterproofing design are appropriate.

Laboratory tile systems
Selected laboratory wall and floor tile systems can use ARADUR 891 adhesives where resistance to inorganic acids and cleaning agents is required.

Chemical-processing tile areas
Tile linings in selected chemical-processing zones can use ARADUR 891 where the exposure profile falls within the validated resistance envelope.

Industrial floor tiles
Heavy-duty ceramic or mineral floor tiles can be bonded using filled epoxy adhesive systems designed for traffic and chemical cleaning.

Wall tiles
Vertical tile bonding can use ARADUR 891 when the formulation contains sufficient thixotropy to prevent slip.

Ceramic tiles
Ceramic tile is a principal substrate type for epoxy tile adhesives.

Quarry tiles
Industrial quarry-tile systems can use chemically resistant epoxy adhesive where bond-line thickness and substrate preparation are controlled.

Stone tiles
Selected stone tiles can be bonded after compatibility, porosity and staining risk have been evaluated.

Chemical-resistant tile adhesive
Good inorganic-acid resistance makes ARADUR 891 especially relevant where the tile adhesive is exposed to acidic cleaning or process chemicals.

Water-resistant tile adhesive
The cured epoxy network can provide strong water resistance when fully cured and correctly proportioned.

Solvent-free tile adhesive
The solvent-free hardener enables high-solids filled adhesive formulations without relying on a volatile carrier solvent.

Construction adhesives
Beyond tile bonding, ARADUR 891 can be used in selected civil-engineering adhesive systems where its low viscosity and relatively long working time are 
advantageous.

Concrete bonding
Prepared concrete can be bonded with compatible epoxy adhesive systems where the substrate is sound and adequately prepared.

Masonry bonding
Mineral masonry surfaces can use filled epoxy adhesive where porosity and moisture condition are suitable.

Stone bonding
Selected natural and engineered stone can be bonded where resin staining, thermal movement and substrate preparation are validated.

Repair adhesives
Civil-engineering repair systems can use ARADUR 891 where good working time and mineral-substrate wetting are useful.

Bonding agents
The grade can be formulated into epoxy bonding agents between compatible prepared construction substrates.

Concrete primers
Very low mixed viscosity can support primer formulations used to wet and penetrate prepared concrete.

Mineral-substrate primers
Mortar, masonry and other mineral surfaces can use compatible low-viscosity epoxy primers.

Floor primers
Industrial flooring systems can use ARADUR 891 primer technology where a longer application window is desirable.

Primer-sealers
Porous mineral surfaces can be sealed with low-viscosity epoxy systems designed to consolidate surface porosity.

Industrial flooring
Older civil-engineering positioning and low-viscosity solvent-free performance make industrial floor systems a relevant formulation area when the full 
coating has been validated.

Self-leveling flooring
ARADUR 891 can be evaluated in filled self-leveling systems where the approximately 100-minute gel time provides longer flow and application time.

Epoxy mortars
Mineral-filled epoxy mortar can use the low-viscosity hardener for efficient aggregate wetting.

Repair mortars
Concrete repair systems can use ARADUR 891 where long enough working time is needed for placement and finishing.

Epoxy screeds
Highly filled screeds can use the grade when resin compatibility and mechanical performance are validated.

Epoxy grouts
Filled grout formulations can use ARADUR 891 where flow, chemical resistance and working time fit the application.

Construction joint adhesives
Rigid construction joints or bonding details can use filled epoxy systems where movement demand is limited.

Chemical anchoring formulations
Anchoring systems can use compatible epoxy chemistry where cure time and bond strength are validated.

Crack-injection systems
The low viscosity of ARADUR 891 can support low-viscosity epoxy injection concepts, although the complete resin-hardener system must be qualified for crack 
width, injection pressure and cure.

Protective concrete coatings
Concrete surfaces can use high-solids epoxy coatings where chemical resistance and water resistance are required.

Industrial maintenance coatings
ARADUR 891 can be evaluated in selected maintenance systems where low viscosity and long working time are beneficial.

Chemical-resistant coatings
Good resistance to inorganic acids supports selected protective-coating uses where the exact chemical exposure is compatible.

Inorganic-acid-resistant coatings
Industrial floors, walls or bonded tile systems exposed to selected inorganic acids can use ARADUR 891 after service-specific testing.

Moderate-solvent-resistance coatings
The current product resistance profile describes solvent resistance as moderate, so solvent-exposed systems should be qualified carefully rather than overclaimed.

High-solids coatings
The solvent-free low-viscosity hardener can support high-solids formulations when resin and filler selection are appropriate.

Solvent-free coatings
ARADUR 891 can be used in solvent-free civil-engineering systems where low hardener viscosity is valuable.

Concrete surface treatment
Low viscosity can improve wetting of porous mineral substrates in compatible treatment systems.

Industrial washdown areas
Facilities exposed to repeated cleaning can use epoxy tile or coating systems when detergent, acid and water resistance have been validated.

Hygienic wall systems
Tile-bonding and protective epoxy systems can be used in hygienic environments where durable sealed surfaces are required.

Process-area flooring
Selected processing floors can use ARADUR 891 systems where exposure is mainly water, cleaners and compatible inorganic acids.

Beverage-plant flooring
Beverage production environments can use epoxy tile or flooring systems after chemical and cleaning-regime validation.

Brewery flooring
Breweries can use compatible tile-bonding or coating systems where acids, water and cleaning chemistry are within the validated range.

Dairy flooring
Dairy production areas can use epoxy tile adhesive and protective systems when temperature, cleaning and organic-acid exposure are evaluated carefully.

General civil-engineering epoxy systems
Other civil-engineering uses are possible where the low viscosity, solvent-free character, long working time and resistance profile match the service 
requirements.

BONDING AND JOINING TILES

The documented ARADUR 891 / ARALDITE GY 783 system is specifically intended for bonding and joining tiles.
An epoxy tile adhesive must provide strong adhesion to both the tile and the supporting substrate.
The binder should wet mineral surfaces before filler structure prevents intimate contact.
The adhesive should remain open long enough for placement and alignment while resisting vertical slip where required.
A properly formulated epoxy joint also provides lower water permeability and greater chemical resistance than many ordinary mineral-based binders.
The complete system should be evaluated for bond strength, open time, slip resistance, cure, water resistance and service chemicals.

BATHROOM AND WET-AREA USE

Bathrooms are specifically mentioned in current application guidance.
Wet-area tile adhesive must maintain adhesion after repeated water exposure and cleaning.
The supporting substrate must be structurally sound and waterproofing design should be appropriate to the building system.
Epoxy adhesive does not replace a required waterproofing membrane where local construction practice requires one.
The cured adhesive should be allowed to reach adequate cure before prolonged water exposure.
Joints, corners and movement zones should be detailed separately rather than relying on a rigid epoxy bond to accommodate major building movement.

FOOD-PROCESSING ENVIRONMENTS

Slaughterhouses, dairies, breweries and beverage-filling stations are specifically identified application environments for ARADUR 891 tile adhesive.
These facilities often combine repeated washdown, cleaning chemicals, temperature variation and organic residues.
Good inorganic-acid resistance is useful, but the current product information states that resistance to organic acids is less good.
This distinction is important in food and beverage environments because lactic, acetic, citric and other organic acids can be present.
The exact cleaning chemicals and process fluids should therefore be tested against the complete adhesive or flooring formulation.
Hygienic design also depends on joint geometry, surface smoothness and the cleanliness of the entire tile system.

INORGANIC ACID RESISTANCE

Current product-specific information states that ARADUR 891 systems have good resistance to inorganic acids.
This can be valuable in industrial construction environments exposed to selected mineral-acid cleaning or process chemicals.
The statement should not be interpreted as universal resistance to every inorganic acid at every concentration and temperature.
Hot concentrated acid exposure is more severe than dilute room-temperature splash.
The selected epoxy resin strongly influences final resistance.
Service-specific immersion or splash testing should therefore be performed where acid exposure is critical.

ORGANIC ACID LIMITATION

Current product-specific information states that resistance to organic acids is less good than resistance to inorganic acids.
This limitation is especially important in breweries, dairies, beverage plants and food-processing environments where organic acids can occur.
Acetic acid, lactic acid and citric acid exposure can challenge epoxy systems differently from inorganic acids.
A tile adhesive or coating should therefore be tested with the actual process chemical and concentration.
A general statement that ARADUR 891 is acid resistant would be too broad without distinguishing acid type.
Formulation and resin selection can improve or reduce the final resistance profile.

OXIDIZING ACID LIMITATION

Current product-specific information also describes resistance to oxidizing acids as less good.
Oxidizing acids can attack organic polymer networks through both acidity and oxidation.
This makes them substantially more severe than many non-oxidizing mineral acids.
ARADUR 891 systems should not be selected for strong oxidizing-acid service without dedicated testing.
Higher-functionality or specialty resin chemistry may be required where severe oxidizing conditions exist.

SOLVENT RESISTANCE

Current product positioning lists solvent resistance as the primary feature, while the detailed current resistance statement characterizes practical solvent resistance as moderate.
The two statements should be interpreted together: solvent resistance is a relevant product capability, but the complete system is not universally resistant to every organic solvent.
Polar solvents, ketones, aromatic hydrocarbons and chlorinated solvents can be much more severe than water or mild cleaning agents.
The selected epoxy resin and cure completeness strongly influence solvent uptake.
Continuous immersion should be treated as more severe than short splash or wipe exposure.
The exact solvent or cleaning blend should be tested before specifying the system for demanding service.

LOW-TEMPERATURE CURE BEHAVIOR

Current product-specific information states that the curing process slows at temperatures below approximately 20°C.
Lower temperature increases resin and hardener viscosity and reduces molecular mobility, causing slower epoxy-amine reaction.
The approximately 100-minute room-temperature gel time can therefore become substantially longer in cold conditions.
Application planning should allow more time for cure before loading, washing or chemical exposure.
Substrate temperature should be measured directly because concrete or tile can be colder than the surrounding air.
Condensation and dew-point conditions should also be controlled.

ACCELERATOR 960-1 GUIDANCE

Current product-specific guidance states that the cure delay below approximately 20°C can be compensated by adding small quantities of Accelerator 960-1.
This should be treated as a formulation adjustment rather than an automatic field correction.
Accelerator addition can shorten pot life and change cure development.
The amount should therefore follow validated formulation guidance and should be confirmed through practical gel-time and property testing.
Too much accelerator can reduce the generous working time that makes ARADUR 891 attractive in tile and civil-engineering applications.
Current product-specific technical guidance should control use level.

POT LIFE

The approximately 100-minute reference gel time provides a relatively generous application window.
Practical pot life can still be shorter because filled adhesive begins to thicken before complete gelation.
Warm resin, warm hardener and large mixed batches shorten working time.
Cold conditions extend working time but also delay final cure.
Tile installers should mix only the amount that can be spread and covered within the validated open time.
Material that has chemically advanced should not be thinned with water or solvent and reused.

EXOTHERM CONTROL

Epoxy-amine cure is exothermic.
ARADUR 891 is less reactive than many fast amine hardeners, but large mixed batches can still self-heat.
A deep pail of mixed adhesive can react faster than a thin layer spread onto a floor or wall.
Mineral filler reduces the fraction of reactive binder and absorbs some heat.
Batch size should nevertheless be scaled carefully during manufacturing and site work.
Unused mixed material should not be left in a sealed container where heat cannot dissipate.

TILE-ADHESIVE RHEOLOGY

ARADUR 891 itself is very low in viscosity, but a tile adhesive must usually be thixotropic enough to hold a notched-trowel profile and resist tile slip.
Mineral fillers, thixotropes and particle-size distribution create the required body.
The formulation should spread under trowel shear but recover enough structure after placement.
Excessive thickening can reduce wetting and shorten apparent open time.
Insufficient structure can allow heavy wall tiles to slide.
Rheology should therefore be evaluated together with tile size, orientation, bond-line thickness and substrate porosity.

FILLERS AND AGGREGATES

Tile adhesives and civil-engineering systems based on ARADUR 891 can contain high mineral-filler loading.
Silica, quartz, calcium carbonate and other compatible fillers can adjust viscosity, body, shrinkage and cost.
Filler moisture and soluble salts should be controlled.
Fine particles increase surface area and can raise resin demand.
A broad particle-size distribution can improve packing and reduce the amount of binder needed for a given consistency.
The low viscosity of ARADUR 891 is particularly useful because it helps wet high filler surface area efficiently.

PIGMENTS

Pigments can be used in colored tile adhesives, grouts, coatings and flooring systems.
Titanium dioxide, iron oxides and compatible inorganic pigments are typical classes that may be evaluated.
Pigment surface chemistry can affect viscosity, dispersant demand and cure.
High pigment loading can reduce flow and increase apparent pot-life loss.
The final formulation should be checked for color uniformity, adhesion, cure and chemical resistance.

WATER CLEANUP

The current system description states that uncured material can be washed down with water.
This can simplify tool cleanup compared with systems that require organic cleaning solvent.
Water cleanup should occur before the epoxy network develops substantially.
Partially cured material can become increasingly difficult to remove.
Cleaning water should be collected and managed responsibly because it can contain reactive epoxy and amine components.
Water washability during application does not imply that a fully cured adhesive will dissolve in water.

CONCRETE PREPARATION

Concrete substrates should be mechanically sound and free from weak laitance, dust, oil, grease, curing compounds and loose material.
Grinding or shot blasting can expose sound concrete and improve surface profile.
The low viscosity of ARADUR 891 systems supports good wetting of properly prepared mineral surfaces.
Very porous concrete can absorb binder and create a starved adhesive interface if formulation or application rate is inadequate.
Concrete moisture should be evaluated because current tile-adhesive positioning does not by itself establish unrestricted wet-concrete bonding.
Pull-off or bond testing can be useful in demanding industrial installations.

TILE SURFACE PREPARATION

Tile backs should be free from dust, release agents, oil and other contamination that can interfere with adhesive wetting.
Dense glazed or vitrified tile can require a different surface-preparation approach than porous ceramic or quarry tile.
Natural stone can contain pores, moisture or minerals that affect staining and bond performance.
The adhesive should achieve adequate contact across the required percentage of the tile back.
Large-format tile installation requires careful control of adhesive thickness and voids.
Site-specific mock-ups can confirm open time, slip resistance and bond quality.

MASONRY AND MORTAR SUBSTRATES

Masonry and mortar can be bonded or coated with ARADUR 891 systems when the mineral substrate is strong and stable.
Weak powdery surfaces should be removed before application.
Very high absorption can require priming or adjusted application rate.
Moving cracks and structural joints should not be rigidly bridged without engineering evaluation.
The relatively long working time is useful on irregular mineral surfaces where placement takes longer.

ADHESION

Strong adhesion is essential to successful tile and civil-engineering systems.
The low viscosity of ARADUR 891 helps the epoxy binder contact mineral microtexture and penetrate surface pores.
Adhesion can still fail if the substrate is weak, contaminated or excessively wet.
The final bond strength depends on resin chemistry, filler loading, mix ratio and cure.
Adhesion should be evaluated after adequate cure and after relevant water or chemical exposure.
A failure within weak concrete or tile substrate should be distinguished from adhesive failure at the epoxy interface.

WATER RESISTANCE

Cured epoxy systems can provide strong water resistance when fully crosslinked.
This makes ARADUR 891 tile adhesive relevant to bathrooms and frequent-washdown industrial environments.
Rapid water exposure before adequate cure can reduce early bond performance.
Water resistance should be tested together with repeated cleaning and temperature cycling where service is demanding.
The current water-washable handling claim applies to uncured material and should not be confused with final water resistance.
Continuous immersion applications require separate qualification.

CHEMICAL-RESISTANCE TESTING

Chemical resistance should be evaluated on the complete cured formulation rather than on the hardener alone.
ARADUR 891 has good inorganic-acid resistance, less good organic- and oxidizing-acid resistance and moderate solvent resistance in the documented reference system.
Resin choice can change this balance substantially.
Tile adhesive can also contain fillers that reduce polymer volume but do not necessarily improve chemical resistance.
Exposure testing should reproduce the actual concentration, temperature and cleaning cycle where possible.
Visual appearance, hardness, mass change and bond strength after exposure can all be relevant acceptance criteria.

INTERCOAT AND OVERLAY BONDING

ARADUR 891 can be used in civil-engineering systems where one epoxy layer must bond to another coating, mortar or overlay.
The following layer should be applied within the validated recoat or overlay window where chemical bonding is desired.
Fully cured surfaces can require cleaning and mechanical abrasion.
Dust, wash residues or amine-related surface contamination should be removed before recoating.
The relatively long cure profile can provide a practical window for sequential construction work.

WEATHERING

ARADUR 891 is primarily a civil-engineering and tile-adhesive hardener rather than an exterior UV-stable finish technology.
Conventional epoxy resin can yellow, chalk or lose gloss under prolonged sunlight.
Exterior tiled or coated surfaces should use an appropriate weather-resistant system where appearance is important.
Indoor wet areas, hygienic production spaces and industrial tile installations are less affected by this limitation.
Weathering performance should be evaluated on the complete construction system.

QUALITY CONTROL

Important ARADUR 891 quality-control parameters include appearance, viscosity, amine value, density and functional cure behavior.
Current viscosity is approximately 130-190 mPa·s at 25°C.
Current amine value is approximately 520-540 mg KOH/g and density approximately 0.94 g/cm³ at 20°C.
Current flash point is approximately 110°C closed cup.
Current product-specific reference gel time is approximately 100 minutes with ARALDITE GY 783 at 23°C and 250 g.
Older selector data additionally provide AHEW approximately 74-82 g/eq and Gardner color ≤10.
A batch-specific COA should take precedence for formal incoming acceptance where supplied.

WHY VISCOSITY MATTERS

The approximately 130-190 mPa·s viscosity is unusually low for a formulated polyamidoamine.
Low viscosity improves pumping, mixing, mineral wetting and filler incorporation.
It also makes solvent-free formulation practical without relying on benzyl alcohol or a conventional carrier solvent.
Unexpectedly high viscosity can indicate low temperature, contamination or aging.
Unexpectedly low viscosity can indicate dilution or incorrect material.
Viscosity should be compared at the specified 25°C condition.

WHY AHEW MATTERS

The historical / selector AHEW range of approximately 74-82 g/eq provides a stoichiometric bridge between hardener chemistry and resin EEW.
For a resin around EEW 190 g/eq, this range predicts roughly 39-43 phr hardener.
The current documented GY 783 ratio of 40 phr fits within this expected range.
AHEW should be used rather than amine value for theoretical epoxy-equivalent calculation.
The exact current production ratio should nevertheless follow product-specific system guidance.

WHY GEL TIME MATTERS

The approximately 100-minute current reference gel time provides a comparatively long processing window.
This is useful for tile installation because spreading, combing, placement and adjustment require time.
Gel time is still affected by batch mass and temperature.
Practical open time can be shorter than gel time in a filled adhesive.
The final formulation should therefore establish real field working time independently.

BENZYL-ALCOHOL-FREE STATUS

Older ambient-curing selector literature marks ARADUR 891 as benzyl-alcohol-free.
This is consistent with the current product's solvent-free, very-low-viscosity positioning.
Benzyl alcohol is sometimes used in epoxy hardeners to reduce viscosity or modify cure, but ARADUR 891 achieves low viscosity without relying on that modifier.
The complete formulation should still be reviewed because another component could introduce benzyl alcohol.
Formal restricted-substance claims should rely on current product-specific documentation.

CURRENT INVENTORY LISTINGS

Current product information lists ARADUR 891 on multiple chemical inventories including AIIC, DSL, ENCS, IECSC, KECI, PICCS, TCSI and TSCA.
Inventory status is time-sensitive and can be affected by regional interpretation, exemptions or regulatory updates.
A listing should not be treated as approval for a specific end use.
Current compliance documentation should be checked for the jurisdiction in which the product or finished formulation will be supplied.

TDS, SDS AND COA

The current Technical Data Sheet should control present specifications, tile-adhesive guidance and the documented ARALDITE GY 783 mix ratio.
The Safety Data Sheet governs formal component disclosure, hazards, first aid, fire response, storage, transport and disposal.
The Certificate of Analysis provides batch-specific controlled values where supplied.
Current product data support the 130-190 mPa·s viscosity, 520-540 mg KOH/g amine value, 0.94 g/cm³ density, 110°C flash point, 100-minute GY 783 gel time and 100:40 GY 783 / ARADUR 891 mix ratio.
Older selector literature supports AHEW approximately 74-82 g/eq, Gardner color ≤10, CE positioning, benzyl-alcohol-free status and approximately 100-minute GY 250 selector gel time.
Where current product-specific values differ from older selector ranges, the current values should take precedence.

SAFETY AND HANDLING

ARADUR 891 is a reactive amine-containing curing agent and should be handled according to the current product-specific SDS.
Direct skin and eye contact should be avoided.
Chemical-resistant gloves, suitable eye protection and protective clothing should be selected through workplace risk assessment.
Adequate ventilation should be used during mixing, spreading or any operation that can generate mist or vapor.
The high flash point does not remove the need for good fire-prevention practice.
Large mixed batches should be controlled because epoxy cure is exothermic.

FIRST AID

After skin contact, contaminated skin should be washed promptly according to current SDS guidance and contaminated clothing should be removed.
If material enters the eyes, immediate prolonged rinsing with clean water should begin and medical attention should be obtained according to the SDS.
If mist or vapor is inhaled and symptoms occur, move the affected person to fresh air and obtain appropriate medical advice.
After accidental ingestion, follow the current product-specific SDS and professional medical guidance.
Generic first-aid assumptions should not replace current instructions for the exact commercial formulation.

SPILL MANAGEMENT

Spilled ARADUR 891 is a low-viscosity liquid and can spread across floors rapidly.
The affected area should be contained promptly and personnel should use appropriate PPE.
The product should be prevented from entering drains, soil, groundwater or natural waterways.
Compatible inert absorbent can be used for smaller spills, while larger releases may require pumping or specialist response.
Recovered material and contaminated absorbent should be placed in suitable labeled containers.
Current SDS and local waste requirements should control final disposal.

FIRE RESPONSE

ARADUR 891 has a current flash point of approximately 110°C by Pensky-Martens closed-cup testing.
The product can burn or decompose under severe heating despite the relatively high flash point.
Thermal decomposition can generate carbon oxides, nitrogen-containing fumes and irritating organic vapors.
Firefighters may require self-contained breathing apparatus and appropriate protective clothing.
Extinguishing media and emergency procedures should follow the current product-specific SDS and facility fire plan.

STORAGE

Current product information specifies dry storage, preferably in the sealed original container, at approximately 2-40°C.
Storage temperature should never be allowed to fall below 0°C.
Direct sunlight should be avoided.
The container should remain tightly closed to reduce contamination and atmospheric exposure.
Material stored cold should be allowed to reach a suitable processing temperature before viscosity-sensitive use.
The original package expiry information and current product-specific documentation should control shelf-life decisions.

REGULATORY CONSIDERATIONS

ARADUR 891 is a proprietary formulated polyamidoamine hardener used primarily in civil-engineering adhesive systems.
Current inventory listings do not establish approval for food contact, potable water, medical devices or other regulated applications.
Use in slaughterhouses, dairies, breweries or beverage facilities refers to construction application environments and should not be converted automatically into a direct food-contact claim.
The complete tile adhesive or coating formulation must be assessed independently for any regulated use.
Formal environmental and restricted-substance statements should rely on current product-specific documentation.

ENVIRONMENTAL CONSIDERATIONS

The solvent-free low-viscosity character of ARADUR 891 can support lower-emission adhesive and coating formulations.
Uncured hardener should nevertheless not be released directly to drains, soil or natural waterways.
Water-washable handling should not lead to uncontrolled discharge of contaminated wash water.
Cleaning waste can contain resin, hardener, filler and other formulation components and should be managed appropriately.
Large masses of mixed resin and hardener can generate heat during cure and should not be accumulated in uncontrolled waste containers.
Fully cured epoxy has different mobility and reactivity from uncured components, but disposal requirements remain jurisdiction specific.

COMMON FORMULATION PROBLEMS

Tile adhesive is too fluid
ARADUR 891 is extremely low in viscosity. Increase compatible filler or rheology control while preserving wetting and open time.

Wall tiles slip
The formulation does not recover enough structure after troweling. Improve thixotropy and verify tile weight, notch size and bond-line thickness.

Adhesive is too stiff to spread
Excess filler, low temperature or excessive thixotrope can raise viscosity. Rebalance the mineral package or condition the components appropriately.

Pot life is shorter than expected
Warm materials, large batch size or added accelerator can shorten working time. Reduce batch size and standardize temperature.

Pot life is much longer in cold weather
Cure slows below approximately 20°C. Allow longer cure or use validated small additions of Accelerator 960-1 where current guidance supports it.

Adhesive remains soft overnight in cold conditions
The temperature may be too low for normal cure development. Verify mix ratio, substrate temperature and accelerator guidance.

Poor tile adhesion
Dust, release agents, contamination, weak substrate or late application can prevent wetting. Correct surface preparation and process timing.

Poor concrete adhesion
Weak laitance, oil, curing compounds or excessive moisture can create a weak interface. Prepare and clean the substrate.

Adhesive bond fails after washdown
The system may have been exposed to water before adequate cure or the substrate was contaminated. Verify cure time and surface preparation.

Organic-acid exposure damages the system
ARADUR 891 has less good resistance to organic acids than to inorganic acids. Test the actual organic acid and select a more resistant system if required.

Oxidizing-acid exposure causes degradation
Resistance to oxidizing acids is less good. Avoid overclaiming and qualify a specialty system for severe oxidizing service.

Solvent exposure softens the adhesive
Current detailed resistance guidance describes solvent resistance as moderate. Test the actual solvent concentration, duration and temperature.

Adhesive has poor acid resistance despite correct cure
The epoxy resin may be unsuitable for the exact acid or temperature. Chemical resistance belongs to the complete network, not the hardener alone.

Filler settlement
Very low binder viscosity can allow dense filler to settle. Improve particle-size distribution and low-shear structure.

Air bubbles remain in the adhesive
High-speed mixing or porous substrates can introduce air. Reduce mixing aeration and optimize application.

Pinholes in coating
Concrete outgassing, entrained air or insufficient wetting can create defects. Prime appropriately and control substrate temperature.

Poor self-leveling
Excess filler or thickener can reduce flow. Adjust rheology and apply the formulation earlier in its pot life.

Sagging in vertical coating
Low mixed viscosity can cause sag. Add compatible anti-sag structure or reduce wet-film thickness.

Slow hardness development
Cold temperature, incorrect ratio or incompatible resin can delay cure. Verify system conditions and current formulation guidance.

Brittle cured adhesive
A rigid resin, excessive filler or off-ratio cure can reduce toughness. Rebalance the formulation.

Poor intercoat adhesion
Surface contamination, excessive cure or inadequate preparation can reduce bonding to the next layer. Clean or abrade as required.

Unexpectedly high viscosity
Low temperature, contamination or aging can raise viscosity. Condition the material to 25°C and compare with the expected 130-190 mPa·s range.

Unexpectedly low viscosity
Dilution, excessive temperature or incorrect material can lower viscosity. Check density, amine value and functional cure.

Amine value specification shows 520-550 instead of 520-540
Older selectors used the broader 520-550 mg KOH/g range. Current product-specific data give 520-540 mg KOH/g and should be treated as primary.

Gel-time documentation mentions both GY 250 and GY 783
Older selector data give approximately 100 minutes with GY 250, while current product-specific data give approximately 100 minutes with GY 783. Preserve the test basis rather than merging them.

Mix ratio copied to another resin
The current 100:40 ratio is specific to the ARALDITE GY 783 reference system. Recalculate or use current guidance for other resins.

Too much Accelerator 960-1
Excess acceleration can reduce working time sharply. Use only validated small additions and confirm field pot life.

Water cleanup attempted after cure
Water washability applies to uncured handling. Fully cured epoxy is crosslinked and will not simply wash away.

Wash water discharged directly
Water cleanup does not make uncured components environmentally harmless. Collect and manage contaminated wash water appropriately.

Brewery or dairy service assumed universally suitable
Organic acids and cleaning chemicals vary. The current resistance profile requires service-specific testing rather than blanket approval.

Food-contact claim inferred from food-processing environment
Use in food-processing facilities does not establish direct food-contact approval. Evaluate the complete finished construction system separately.

FREQUENTLY ASKED QUESTIONS

What is ARADUR 891?
ARADUR 891 is a very low-viscosity, solvent-free formulated polyamidoamine epoxy hardener used primarily in civil-engineering tile-adhesive systems.

What is the current viscosity?
Approximately 130-190 mPa·s at 25°C.

What is the current amine value?
Approximately 520-540 mg KOH/g.

Why do older selectors show 520-550 mg KOH/g?
Older selector literature used a slightly broader amine-value range. The current product-specific 520-540 mg KOH/g range should be treated as primary.

What is the active hydrogen equivalent weight?
Older selector literature gives approximately 74-82 g/eq.

What is the density?
Approximately 0.94 g/cm³ at 20°C.

What is the flash point?
Approximately 110°C by Pensky-Martens closed-cup testing.

What is the current reference gel time?
Approximately 100 minutes at 23°C using a 250 g ARALDITE GY 783 reference system.

Does older selector literature use ARALDITE GY 250?
Yes. Older selector literature also gives approximately 100 minutes with ARALDITE GY 250 under the selector comparison method.

What is the optimum current mix ratio?
Approximately 100 parts ARALDITE GY 783 to 40 parts ARADUR 891 by weight.

What is the main current application?
Tile adhesive.

Where is the tile-adhesive system used?
Documented examples include bathrooms, slaughterhouses, dairies, breweries and beverage-filling stations.

Is ARADUR 891 solvent free?
Yes. Current product information describes ARADUR 891 as solvent-free.

Can uncured ARADUR 891 systems be washed with water?
Current product information states that the documented system can be washed down with water before full cure.

Does water washability mean the cured epoxy is water soluble?
No. Water washability is an uncured handling feature; the cured epoxy network is crosslinked.

Is ARADUR 891 benzyl-alcohol-free?
Older ambient-curing selector literature marks ARADUR 891 as benzyl-alcohol-free.

Does ARADUR 891 resist inorganic acids?
Yes. Current product information states good resistance to inorganic acids.

Does ARADUR 891 resist organic acids?
Resistance to organic acids is described as less good, so food and beverage process exposures should be tested carefully.

Does ARADUR 891 resist oxidizing acids?
Resistance to oxidizing acids is described as less good.

Does ARADUR 891 resist solvents?
Current detailed guidance describes practical solvent resistance as moderate, so the exact solvent exposure should be tested.

Can ARADUR 891 be used below 20°C?
It can cure, but current product guidance states that cure slows below approximately 20°C.

Can the cold cure be accelerated?
Current guidance states that small quantities of Accelerator 960-1 can compensate for cure delay below approximately 20°C when used in a validated formulation.

Can ARADUR 891 be used for civil-engineering systems beyond tile adhesive?
Yes. Its low viscosity, solvent-free character and selector CE positioning make primers, flooring, mortars and other compatible civil-engineering formulations relevant when validated.

Can ARADUR 891 be used on concrete?
Yes. Low viscosity supports wetting of prepared mineral substrates, but surface preparation and moisture condition remain important.

What is the theoretical hardener level with resin EEW 190?
Using the historical 74-82 g/eq AHEW range gives approximately 38.9-43.2 parts ARADUR 891 per 100 parts resin.

Does the 40 phr GY 783 ratio fit that theoretical range?
Yes. The current 100:40 mix ratio is consistent with the historical AHEW range for a typical liquid epoxy resin.

Does ARADUR 891 have one universal CAS number?
No. It is a proprietary formulated polyamidoamine mixture and should not be assigned one universal CAS number without the current product-specific SDS.

How should ARADUR 891 be stored?
Store it dry, preferably in the sealed original container, at approximately 2-40°C, never below 0°C, and protect it from direct sunlight.

Which chemical inventories are currently listed?
Current product information lists AIIC, DSL, ENCS, IECSC, KECI, PICCS, TCSI and TSCA, subject to current regional confirmation.

What documents should be checked before use?
Use the current product TDS, SDS and batch-specific COA or quality documentation where available.

FINAL TECHNICAL SUMMARY

ARADUR 891 is a very low-viscosity, solvent-free formulated polyamidoamine epoxy hardener developed primarily for civil-engineering tile-adhesive systems.
Current product-specific data give approximately 130-190 mPa·s viscosity at 25°C, 520-540 mg KOH/g amine value, density around 0.94 g/cm³ at 20°C and flash point around 110°C closed cup.

Current product-specific gel time is approximately 100 minutes at 23°C using a 250 g ARALDITE GY 783 reference system.
The documented optimum ARALDITE GY 783 / ARADUR 891 mix ratio is approximately 100:40 parts by weight.
Older ambient-curing selector literature gives AHEW approximately 74-82 g/eq, Gardner color ≤10, benzyl-alcohol-free status and approximately 100 minutes gel time with ARALDITE GY 250.
The current 520-540 mg KOH/g amine-value range should take precedence over the older 520-550 mg KOH/g selector range.
Tile adhesive is the primary current end use.

The documented ARALDITE GY 783 / ARADUR 891 adhesive system is used for bonding and joining tiles in bathrooms, slaughterhouses, dairies, breweries and beverage-filling stations.
Current product information describes ARADUR 891 as solvent-free and unusually low in viscosity for a formulated polyamidoamine.
The low viscosity supports easy processing, filler wetting, mineral-substrate wetting and high-solids civil-engineering formulations.
Current information also states that the uncured system can be washed down with water, which can simplify application cleanup.
Water washability is an uncured handling feature and should not be confused with water solubility of the cured epoxy network.
The current resistance profile is nuanced: good resistance to inorganic acids, less good resistance to oxidizing and organic acids, and moderate resistance to solvents.
This distinction is especially important in dairies, breweries and beverage plants because organic acids can be present.

Current product guidance states that cure slows below approximately 20°C.
Small quantities of Accelerator 960-1 can be used to compensate for cold-temperature cure delay where a validated formulation supports the addition.
Current storage guidance is approximately 2-40°C in a dry sealed original container, with temperature never allowed to drop below 0°C and direct sunlight avoided.
ARADUR 891 is a proprietary formulated polyamidoamine and should not be assigned an invented single molecular formula, molecular weight, CAS number or EC number.

For ARADUR 891 technical specifications, current TDS, SDS, COA, tile-adhesive formulation support and civil-engineering application guidance, contact Ataman Chemicals with the intended epoxy resin, substrate, temperature and chemical-exposure conditions.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com