ARADUR 39

ARADUR 39 is a waterborne modified polyamine-adduct epoxy curing agent developed for two-component ambient-cured coatings that require fast drying, rapid cure, strong adhesion, high gloss, good flow and low odor without the use of volatile organic solvent in the hardener. The commercial product is supplied as an approximately 50% solids solution in water and is particularly suited to liquid epoxy resins used in breathable concrete primers, clear sealers, self-priming floor coatings, civil-engineering systems and selected zero-VOC adhesive formulations. ARADUR 39 is especially valuable where coating performance must be maintained on dry, damp or wet mineral substrates and where rapid cure is required at normal or relatively low application temperatures.

PRODUCT IDENTITY

Product name: ARADUR 39
Product type: Waterborne epoxy curing agent / hardener
Chemical family: Polyamines
Specific chemistry: Modified polyamine adduct
Carrier: Water
Physical form: Liquid
Appearance: Clear to slightly hazy colloidal solution
Color: Light yellow; Gardner color ≤5 in TDS information
Odor: Slight / very low odor
Solids content: Approximately 49-51%; generally described as 50% solids in water
Water content: Approximately 49-51% by difference from the commercial solids level
Organic solvent content: No organic solvents in the supplied hardener
Viscosity at 25°C: Approximately 12,000-20,000 mPa·s
Amine value: Approximately 120-140 mg KOH/g
Active hydrogen equivalent weight: Approximately 330-335 g/eq as supplied
Density at 25°C: Approximately 1.07 g/cm³ / 8.9 lb/gal
Flash point: Greater than approximately 93°C, closed cup
Reference use level with ARALDITE GY 9708-3: Approximately 150-200 phr
Typical historical pot life: Approximately 3-4 hours in technical literature
Primary current functions: Curing agent and hardener
Primary current end use: Waterborne coatings
Material compatibility: Mineral substrate
Primary current product features: Excellent adhesion, fast cure, fast drying, high gloss, improved pot life, improved flow and low odor
Additional current positioning: Concrete primers and coatings with high water-vapor transmission to reduce blistering on continuously damp floors
Low-temperature cure: Current information highlights rapid curing around 5°C and historical TDS data describe fast drying and curing below 10°C with adequate ventilation
Humidity tolerance: Current information highlights cure across a wide humidity range
Concrete adhesion: Current information highlights excellent adhesion to dry, damp or wet concrete
Water dilution: Can be diluted with water down to approximately 30% solids, although haze may develop
Solid-resin dispersion compatibility: Not recommended because insufficient coalescence can occur in cast films
Recommended resin type: Liquid epoxy resin systems
Historical liquid resin example: ARALDITE GY 9708-3
Historical applications: Water-reducible zero-VOC coatings, zero-VOC adhesives and civil engineering
Storage temperature: TDS approximately 2-40°C in sealed original packaging, protected from direct sunlight
Historical shelf life: Approximately 2 years under the stated storage conditions; current product documentation should govern present shelf-life decisions
CAS Number: Commercial waterborne modified polyamine-adduct mixture; no single CAS number should be assigned to the complete trade grade without the current SDS
EC Number: Commercial mixture; no single EC number should be assigned to the complete trade grade without the current SDS
Molecular Formula: Not applicable to the commercial mixture
Molecular Weight: Variable / not applicable as one fixed value
ARADUR 39 should be treated as a proprietary formulated polyamine-adduct curing-agent mixture rather than as one discrete molecular compound. The active hardener contains a distribution of amine-containing structures and is supplied in a substantial water phase. One molecular formula, molecular weight or universal trade-product CAS number would therefore be technically misleading. Current SDS documentation should be used for formal component identity, concentration ranges and hazard classification.

WHAT IS ARADUR 39?

ARADUR 39 is a waterborne reactive amine hardener designed to cure epoxy resin while allowing the final two-component system to be formulated without volatile organic solvent in the hardener. The product is supplied as a colloidal aqueous solution containing roughly equal proportions of reactive solids and water.
Its most distinctive application profile is fast-drying, breathable waterborne epoxy technology for mineral substrates. currently it emphasizes concrete primers and coatings intended to reduce blistering on floors that remain damp or are located in low-lying areas. This is achieved not by making the epoxy film completely impermeable, but by combining adhesion and chemical resistance with a formulation design that permits useful water-vapor transmission.
ARADUR 39 also differs from many waterborne curing agents because specifically it is advised against combination with solid-resin dispersions. The reason is insufficient coalescence of the cast film. The grade is instead positioned primarily with liquid epoxy resins, where zero-VOC and fast-drying films with good adhesion and flow can be developed.
The combination of fast cure and comparatively long practical pot life is especially valuable. A formulator can maintain a useful working period in the mixed material while still obtaining rapid film development after application.

MODIFIED POLYAMINE ADDUCT CHEMISTRY

ARADUR 39 is described as a modified polyamine adduct. Polyamine adducts are produced by partially reacting amine functionality with a suitable reactive compound before the curing agent is supplied. This increases molecular size and changes compatibility, volatility, reactivity and surface behavior compared with the starting low-molecular-weight amine.
The modified adduct retains primary and secondary amine hydrogens that remain reactive toward epoxy groups. The pre-reaction can improve water compatibility and reduce some of the handling disadvantages of simple amines while preserving enough functionality to create a strongly crosslinked epoxy network.
Because ARADUR 39 is a proprietary commercial grade, the exact molecular distribution should not be simplified to one structure. Functional parameters such as AHEW, amine value, solids, viscosity and validated resin compatibility are more meaningful for formulation.
The aqueous carrier also makes ARADUR 39 chemically and physically different from neat polyamine curing agents. Film formation requires both water removal and chemical crosslinking.

HOW EPOXY CURING WORKS

Epoxy resins contain strained three-membered oxirane rings. Primary and secondary amine hydrogens in ARADUR 39 attack these rings and open them, forming new carbon-nitrogen bonds and hydroxyl groups.
As multiple epoxy and amine sites react, the molecular network becomes increasingly branched and eventually three-dimensional. The initially liquid mixture therefore progresses through viscosity increase, gelation and solid-state cure.
Water in ARADUR 39 is not the principal reactive component of the network. It functions as a carrier and processing medium and must leave the coating during drying. This means water evaporation and epoxy-amine crosslinking proceed together.
A successful waterborne epoxy coating requires these two processes to remain balanced. If water cannot escape, early softness or haze can persist. If the formulation loses colloidal stability before film formation, poor coalescence or separation can occur.

SOLIDS CONTENT

ARADUR 39 is supplied at approximately 50% solids, with selector literature giving a typical range around 49-51%. The other approximately half of the commercial product is primarily water.
This relatively moderate solids level is lower than high-solids waterborne hardeners such as ARADUR 36 or ARADUR 38-1. The formulation therefore introduces more water for each unit of active curing chemistry.
The additional water can support easy dilution and low-VOC processing, but it must be removed from the film before maximum service performance develops. Drying conditions are therefore especially important.
Solids content also affects stoichiometry. Equal wet weights of ARADUR 39 and a 100% solids hardener do not contain equal quantities of reactive curing agent. The commercial AHEW should be used as supplied.

WATER CONTENT

Because ARADUR 39 is approximately 50% solids, water represents roughly half of the supplied material. This water provides the continuous or major carrier phase for the modified polyamine adduct.
Water lowers handling viscosity and enables zero-VOC formulation with suitable liquid epoxy resins. It also allows additional water dilution for application control.
The downside is that water removal becomes a significant part of drying. Thick films, stagnant air and high humidity can extend drying time even though the chemical reaction itself is relatively fast.
Water content should remain within product specification because concentration drift changes active-hardener delivery, viscosity and dry-film behavior.

VISCOSITY

ARADUR 39 has a published viscosity of approximately 12,000-20,000 mPa·s at 25°C. This is characteristic of a concentrated polymeric waterborne hardener rather than a low-molecular-weight neat amine.
Viscosity affects pumping, metering, mixing and application preparation. Additional water can reduce viscosity, but dilution should be controlled because haze can develop as concentration decreases.
Temperature also strongly influences viscosity. Cold product becomes thicker, while warm product becomes easier to pump and disperse. Quality-control comparisons should therefore be made at the specified 25°C test temperature.
Unexpected permanent viscosity changes can indicate water loss, contamination or aging and should be investigated.

AMINE VALUE

The published amine value of ARADUR 39 is approximately 120-140 mg KOH/g. Amine value is an analytical measurement of basic nitrogen functionality expressed as equivalent potassium hydroxide.
This value supports incoming quality control and helps distinguish ARADUR 39 from related curing-agent grades. Significant drift can indicate compositional change.
Amine value is not interchangeable with active-hydrogen equivalent weight. Some nitrogen sites contribute to basicity without supplying the same number of reactive hydrogens.
For formulation stoichiometry, AHEW and resin-specific use-level guidance are more directly useful.

ACTIVE HYDROGEN EQUIVALENT WEIGHT

Technical data list an active-hydrogen equivalent weight around 330 g/eq, while selector literature commonly lists approximately 335 g/eq. The small difference reflects source and document version rather than a fundamentally different product.
AHEW represents the mass of commercial ARADUR 39 needed to supply one equivalent of reactive amine hydrogen. Because the product is approximately 50% water, its as-supplied AHEW is much higher than that of an anhydrous low-molecular-weight amine.
The value is central to theoretical mix-ratio calculations. However, waterborne resin systems involve physical dispersion effects in addition to stoichiometry.
Off-ratio mixing can leave unreacted epoxy or amine functionality and can change flexibility, adhesion, water sensitivity and chemical resistance.

DENSITY

The typical density of ARADUR 39 is approximately 1.07 g/cm³ at 25°C, equivalent to about 8.9 lb/gal.
Density is useful for manufacturing calculations and conversion between weight and volume. Weight-based dosing remains preferable for accurate stoichiometry unless a volumetric system has been calibrated using actual component densities.
A large unexplained density change can indicate concentration drift or contamination, although solids, viscosity and amine value are more direct chemical controls.

FLASH POINT

Technical data list a closed-cup flash point above approximately 93°C. This high value reflects the waterborne, organic-solvent-free nature of the hardener.
A high flash point reduces conventional solvent-fire risk but does not mean the organic curing-agent fraction cannot burn or decompose under severe heating.
Firefighting procedures should therefore follow the current SDS. Thermal decomposition of amine-containing organic material can produce carbon oxides, nitrogen oxides and other hazardous fumes.

ZERO-VOC POSITIONING

ARADUR 39 is designed for coatings formulated without volatile organic compounds from the hardener component.
The current product page states that the grade contains no organic solvents. When combined with appropriate liquid epoxy resins and suitable additives, zero-VOC or very low-VOC coatings can therefore be developed.
The final regulatory VOC value still belongs to the complete formulation. Coalescents, wetting aids, resin carriers or cleaning solvent can contribute VOC even when ARADUR 39 itself does not.
Formal VOC claims should be calculated or measured according to the applicable regional method.

LOW ODOR

Low odor is a product feature, and historical technical information describes the grade as very low odor. This is advantageous in indoor concrete flooring and maintenance applications where worker and occupant exposure to strong solvent or amine odor is undesirable.
Low odor should not be interpreted as low chemical reactivity or harmlessness. Reactive amine functionality can still cause severe skin and eye irritation.
Ventilation remains important, especially during spray application or when other formulation components introduce vapor.

FAST DRYING AND FAST CURE

Fast drying and fast cure are central characteristics of ARADUR 39. Technical data specifically describe fast drying and curing even below 10°C when adequate ventilation is provided.
Current information goes further and highlights rapid cure at temperatures around 5°C as well as normal ambient temperature. This makes the grade attractive for concrete floors and civil-engineering work where application conditions are not always ideal.
Physical drying and chemical cure are related but distinct. Fast epoxy-amine reaction does not remove water automatically; ventilation is still required for the carrier to leave the film.
Well-designed ARADUR 39 systems therefore combine rapid chemical cure with adequate water-vapor transport from the wet coating.

LOW-TEMPERATURE CURE

Low-temperature cure is one of the most practically important properties of ARADUR 39. Conventional waterborne coatings often dry poorly in cool conditions because evaporation slows and polymer mobility decreases.
ARADUR 39 is specifically positioned to retain rapid cure near 5°C and below 10°C in suitably ventilated environments. This allows concrete and mineral coatings to be applied across a wider seasonal temperature window.
Low temperature still increases viscosity and slows water evaporation. Film thickness and airflow therefore become especially important.
Condensation must also be avoided. A cold substrate below the dew point can collect liquid water and interfere with adhesion even when the curing agent itself tolerates damp concrete.

WIDE HUMIDITY TOLERANCE

Current product information highlights curing across a wide range of humidity. This property is especially relevant to concrete because substrate moisture and ambient humidity can vary significantly on construction sites.
Humidity affects water evaporation from a waterborne coating. High relative humidity reduces the evaporation driving force, while dry air removes water more rapidly.
ARADUR 39's formulation design allows useful cure under broad humidity conditions, but adequate ventilation remains important. Saturated stagnant air can still slow physical drying.
Humidity tolerance should not be interpreted as permission to coat surfaces covered with standing water unless the specific formulation is designed and qualified for that condition.

ADHESION TO DRY, DAMP AND WET CONCRETE

Current information specifically highlights excellent adhesion to dry, damp or wet concrete. This is a major differentiator for ARADUR 39 in floor and civil-engineering applications.
Concrete contains capillary pores and can retain substantial moisture. A conventional hydrophobic coating can trap vapor or lose adhesion if the interface is not compatible with this environment.
ARADUR 39-based systems can be formulated to wet mineral surfaces and maintain adhesion while allowing useful vapor transmission. This combination reduces the risk of blistering compared with highly impermeable coatings applied over continuously damp slabs.
Surface preparation remains essential. Oil, dust, weak laitance and curing compounds can still prevent bonding even when moisture tolerance is good.

WATER VAPOR TRANSMISSION

ARADUR 39 is positioned for concrete primers and coatings with high water-vapor transmission. This property is often described as breathability.
A breathable coating allows moisture vapor to move through the film instead of building excessive vapor pressure underneath. This can reduce blistering on floors subjected to continuous or recurring moisture from below.
Water-vapor transmission should not be confused with liquid-water permeability. A coating can resist liquid water or staining while still allowing some vapor diffusion.
Final vapor-transmission rate depends on resin type, film thickness, pigment volume, fillers and degree of cure. Thicker films generally reduce permeability.

BLISTER RESISTANCE ON DAMP FLOORS

Blistering can occur when moisture beneath a coating vaporizes or migrates and creates pressure at the coating-substrate interface. Continuously damp concrete in low-lying areas is particularly vulnerable.
ARADUR 39 is designed for primer and coating systems with enough vapor transmission to reduce this pressure buildup while maintaining adhesion to moist mineral surfaces.
Film thickness must still be controlled. An unnecessarily thick highly filled topcoat can reduce the breathability provided by the primer.
Moisture source, hydrostatic pressure and slab condition should be evaluated before coating because severe active water ingress can exceed the capability of any breathable epoxy system.

HIGH GLOSS

High gloss is one of the product features listed. A smooth continuous film reflects light more uniformly and therefore develops higher gloss.
Good flow contributes directly to this result by allowing brush, roller or application texture to level before the film becomes immobile.
Pigment volume, resin selection, drying rate and substrate texture also affect gloss. Concrete itself can be rough and porous, so high-gloss finish may require appropriate build and surface preparation.
Clear sealers and self-priming floor coatings particularly benefit from the combination of flow and gloss.

FLOW

Improved flow is another current feature. Flow allows the wet coating to redistribute after application and produce a more uniform surface.
Waterborne coatings can develop poor leveling if water evaporates too rapidly or if rheology becomes overly structured. ARADUR 39's formulation profile helps maintain good application flow while still delivering fast cure.
Flow must be balanced against sag. Horizontal floor applications can tolerate more flow than vertical wall coatings.
Rheology modifiers should therefore be selected according to application geometry.

GOOD FLEXIBILITY

Technical information describes ARADUR 39 as providing a combination of good flexibility and fast cure. This balance is useful because rapid-curing epoxy systems can otherwise become brittle.
Flexibility helps a coating tolerate small substrate movement, thermal cycling and mechanical stress without cracking.
Final flexibility depends strongly on resin architecture and hardener ratio. A flexible liquid epoxy or modified resin can produce a different result from a rigid high-functionality epoxy.
Higher hardener proportions within validated limits can also increase flexibility and adhesion.

APPLICATIONS

Concrete primers
Concrete primers are a core current application for ARADUR 39. The grade is particularly suitable where the slab is damp and a breathable epoxy primer is needed to reduce blistering risk. Proper mechanical surface preparation remains essential.

Concrete floor coatings
ARADUR 39 is especially relevant to self-priming concrete floor coatings. Fast cure, high gloss, adhesion to damp concrete and chemical resistance make it suitable for industrial and commercial floor systems where moisture conditions are challenging.

Clear concrete sealers
Current information identifies clear sealers as a particularly suitable application. Clear ARADUR 39-based systems can protect and enhance mineral surfaces while retaining useful water-vapor transmission.

Self-priming floor coatings
A self-priming formulation can combine substrate wetting and finish performance in one coating system. ARADUR 39's adhesion, fast cure and high gloss support this type of design on properly prepared concrete.

Breathable floor coatings
Floors with recurring moisture from below can benefit from coatings designed for higher water-vapor transmission. ARADUR 39 is specifically positioned for this service environment.

Low-lying concrete floors
It is highlighted that floors in low-lying areas where continuous dampness increases blister risk. ARADUR 39-based primers can help by combining moisture-compatible adhesion with vapor transmission.

Damp-concrete coatings
ARADUR 39 is particularly useful where concrete is damp but otherwise sound and clean. The system should still be qualified for the actual moisture level and hydrostatic condition.

Wet-concrete adhesion systems
Current information specifically includes adhesion to wet concrete. Standing surface water, contamination and active leaks should still be managed according to the coating specification.

Water-reducible zero-VOC coatings
 TDS information lists water-reducible zero-VOC coatings as a primary application. ARADUR 39's water carrier and absence of organic solvent make it well suited to this objective.

Industrial floor coatings
Factories, workshops and warehouses can use ARADUR 39-based epoxy floor systems where rapid cure and chemical resistance are required. Traffic should begin only after the coating has reached sufficient cure.

Warehouse floors
Warehouse floors benefit from low odor and fast return to service. Abrasion resistance should be designed through resin choice and aggregate or filler where heavy traffic is expected.

Workshop floors
Workshop coatings can resist oils, cleaning solutions and industrial dirt when the full epoxy system is properly formulated and cured.

Plant-room floors
Mechanical rooms and plant areas can use breathable epoxy systems where concrete moisture is a concern and solvent emissions must remain low.

Utility-room coatings
ARADUR 39 can be used in utility areas where cleanability, adhesion and reduced odor are important.

Laboratory floors
Chemical resistance and smooth cleanable surfaces make epoxy suitable for laboratories. The exact chemical exposure must be validated because resistance depends on the full resin-hardener network.

Commercial floors
Retail back-of-house areas, service corridors and commercial workspaces can use ARADUR 39-based waterborne coatings where high gloss and low odor are desirable.

Basement floors
Basements frequently experience elevated slab moisture. Breathable ARADUR 39 systems can be relevant where vapor transmission is needed to reduce coating blistering.

Parking areas
Sheltered parking surfaces can use compatible breathable epoxy primers or intermediate coats. UV-exposed areas may require a weather-resistant topcoat.

Civil-engineering coatings
Documentation explicitly lists civil engineering as an application. Concrete repair, sealing, priming and protective coating systems are relevant where the formulation matches substrate and service requirements.

Masonry coatings
Mineral-substrate compatibility makes ARADUR 39 relevant to masonry and cementitious surfaces where good adhesion and vapor transmission are important.

Concrete wall coatings
Vertical mineral surfaces can use waterborne epoxy coatings where rheology is adjusted to prevent sag. Fast cure and low odor are useful in occupied or enclosed environments.

Industrial wall coatings
Process areas and utility rooms can use cleanable waterborne epoxy wall finishes. High humidity and ventilation should be considered during application.

Clear mineral sealers
Clear or lightly pigmented sealers can protect concrete and masonry while maintaining a natural substrate appearance. Haze and gloss should be assessed on the actual substrate.

Penetrating primers
Low-viscosity final formulations can penetrate concrete pores and improve adhesion of later layers. Excessive water dilution should be avoided if it compromises solids or film continuity.

Adhesion-promoting primers
ARADUR 39 can be used as part of primer technology where the main objective is strong bonding to mineral substrates before application of subsequent epoxy or compatible coating layers.

Fast-curing primers
Rapid cure at low and normal temperature makes the grade suitable for projects where the recoat interval must remain short.

Cold-weather concrete coatings
ARADUR 39 is particularly attractive for cool conditions 

High-humidity coatings
Broad humidity tolerance allows use in environmental conditions that can challenge many waterborne systems. Actual drying time should still be measured at the intended humidity.

Zero-VOC adhesives
TDS information lists zero-VOC adhesives as an application. Suitable liquid epoxy resins can be combined with ARADUR 39 where bond geometry permits water loss and the cure profile meets the application.

Waterborne epoxy adhesives
Waterborne adhesive systems can benefit from low odor and reduced solvent exposure. Closed, very thick bond lines require careful evaluation because carrier water must escape or be accommodated.

Mineral bonding
ARADUR 39 can be used in epoxy bonding systems for concrete, stone and related substrates where moisture tolerance and adhesion are important.

Repair primers
Concrete repair systems can use ARADUR 39-based primers beneath compatible repair mortars or coatings. The interface should remain clean and within the validated recoat window.

Protective concrete coatings
Industrial concrete exposed to water, oils and chemicals can use ARADUR 39-based protection where the chemical resistance of the complete formulation is suitable.

Stain-resistant floor coatings
Current information describes high chemical and stain resistance as beneficial in self-priming concrete floor coatings and clear sealers.

Low-odor interior coatings
Very low odor makes ARADUR 39 attractive in indoor spaces where solvent smells are undesirable. Adequate ventilation is still required for drying and worker protection.

High-gloss interior epoxy
Suitable liquid epoxy systems can produce smooth high-gloss coatings with ARADUR 39. Exterior weatherability should be considered separately because conventional epoxy can chalk under UV exposure.

LIQUID EPOXY RESIN COMPATIBILITY

ARADUR 39 is primarily intended for liquid epoxy resins rather than solid-resin dispersions. Current information gives ARALDITE GY 9513 and PY 340-2 as examples of compatible liquid resin technology.
Historical technical literature used ARALDITE GY 9708-3 as a reference resin and specified approximately 150-200 phr ARADUR 39. coating literature also identifies GY 776, PY 33757, PZ 756-1/67 and PY 22783 among resin options associated with ARADUR 39 coating systems.
Each resin has its own epoxy equivalent weight, viscosity, emulsification behavior and film-forming profile. A mix ratio should therefore never be transferred automatically from one commercial resin to another.
Compatibility should be confirmed by checking mixing behavior, emulsion stability, gloss, drying time, cure and final water resistance.

ARALDITE GY 9708-3 REFERENCE SYSTEM

TDS information specifies approximately 150-200 parts ARADUR 39 per 100 parts ARALDITE GY 9708-3 resin as a reference use level.
This broad range allows formulation adjustment. It is noted that higher curing-agent proportions up to about 10% by weight beyond the chosen ratio can increase flexibility and adhesion.
The exact optimum depends on required floor or coating properties. More hardener is not automatically better because excess amine can increase water sensitivity or alter chemical resistance.
Modern production should confirm the current availability and specification of the resin grade before relying on a historical ratio.

ARALDITE GY 9513 AND PY 340-2

Current product information specifically cites ARALDITE GY 9513 and PY 340-2 as examples of liquid epoxy resins suitable for ARADUR 39.
With compatible liquid resins, zero-VOC, fast-drying and curing films with good flow and adhesion can be formulated.
The current public product page does not publish a dedicated mix ratio for each of these resins. Formulators should therefore obtain the current resin and hardener technical documents rather than deriving the ratio from GY 9708-3.
Performance should be validated on the intended concrete substrate, particularly when damp-surface adhesion or vapor transmission is critical.

SOLID RESIN DISPERSIONS

Specifically stated that ARADUR 39 is not suitable for combination with solid-resin dispersions because the cast films show insufficient coalescence.
This is an important limitation and should not be ignored simply because another waterborne ARADUR hardener performs well with a solid-resin dispersion.
Solid-resin dispersions require particles to fuse into a continuous film as water leaves. ARADUR 39 does not provide the correct film-forming balance for these systems.
Formulators requiring solid-resin-dispersion technology should select a curing agent explicitly recommended for that resin architecture.

WHY COALESCENCE MATTERS

Coalescence is the physical process through which dispersed resin domains merge into a continuous polymer phase as water evaporates.
If coalescence is poor, the film can remain porous, chalky, hazy or mechanically weak even though some chemical crosslinking occurs.
ARADUR 39 performs well with liquid epoxy resins because the resin phase does not depend on the same particle-fusion mechanism as a solid-resin dispersion.
This explains why chemical compatibility alone is not enough when selecting a waterborne hardener. Physical film formation must also be compatible.

POT LIFE

TDS information describes ARADUR 39 as providing a long pot life, typically around 3-4 hours. This is notable because the same product also produces fast-drying and fast-curing films.
The apparent combination is possible because in-can reaction and thin-film cure do not proceed identically. Water evaporation, surface area, substrate interaction and film thickness all affect cure after application.
Practical pot life should still be established in the final formulation. Pigments, fillers, accelerators and temperature can shorten or lengthen the usable period.
A batch that remains fluid should also be checked for gloss and application behavior because chemical advancement can occur before obvious gelation.

POT LIFE VERSUS FILM CURE

Pot life measures how long the mixed coating remains usable in the container. Film cure describes what happens after the coating is spread into a thin layer.
A thin film has far greater surface area relative to volume, so water can evaporate much more efficiently than from a bulk container. This can accelerate the transition from wet film to cured coating.
Concrete can also absorb part of the water or interact with the resin phase, further differentiating applied behavior from bulk pot life.
ARADUR 39 therefore offers a useful processing window together with rapid film development.

WATER DILUTION

ARADUR 39 may be diluted with water down to approximately 30% solids. This provides significant flexibility in adjusting application viscosity.
As concentration decreases, the material may become hazy. The haze is associated with colloidal structure and does not necessarily mean that the hardener has immediately precipitated.
Very heavy dilution increases the amount of water that must leave the final film. Drying time, sag, film build and early water sensitivity can therefore worsen even when viscosity becomes easier to handle.
Dilution should be standardized and validated with the final resin rather than adjusted informally at the application site.

CONCRETE MOISTURE

Concrete moisture can originate from residual construction water, groundwater, hydrostatic pressure, cleaning or ambient humidity. Moisture moves through capillary pores and can accumulate below an impermeable coating.
ARADUR 39's current positioning specifically addresses this challenge by combining damp-surface adhesion with high water-vapor transmission.
A moisture-tolerant coating is not a substitute for repairing active leaks or severe hydrostatic pressure. Substrate diagnosis remains important.
Moisture testing can help determine whether a breathable coating is appropriate and whether the slab condition is stable enough for epoxy application.

SURFACE PREPARATION

Concrete should be mechanically sound, clean and free from weak laitance, curing compounds, oils, dust and loose material before ARADUR 39 coating application.
Grinding, shot blasting or other mechanical methods can create a clean profile and expose sound mineral surface. The exact method depends on floor condition and required film thickness.
Damp-surface adhesion does not mean contamination tolerance. Oil or weak laitance can still prevent the coating from reaching the actual concrete matrix.
Cracks and joints should be assessed separately because structural movement can exceed the strain capacity of a rigid epoxy film.

CONCRETE ALKALINITY

Fresh or alkaline concrete can present a high-pH surface environment. Epoxy coatings generally tolerate mineral alkalinity better than many acid-sensitive polymers, but the substrate should be sufficiently mature and structurally stable.
Highly alkaline pore solution can interact with pigments and additives even when the epoxy binder itself remains suitable.
Surface preparation and moisture assessment should therefore accompany chemical compatibility testing.

FILM THICKNESS

Film thickness strongly influences breathability. A thicker coating provides a longer diffusion path for water vapor and generally reduces vapor transmission.
ARADUR 39 can be used in breathable primer and coating systems, but excessive build may reduce the moisture-relief advantage.
Primer, intermediate coat and topcoat thicknesses should be designed as a complete system rather than maximizing one coat.
Dry-film thickness should also be sufficient to provide mechanical and chemical protection, so the optimum is a balance rather than simply the thinnest possible film.

CHEMICAL AND STAIN RESISTANCE

Current information highlights high chemical and stain resistance in ARADUR 39 concrete floor coatings and clear sealers.
Chemical resistance comes from the crosslinked epoxy network after sufficient cure. Water, oils, cleaning agents and industrial chemicals can interact differently with the cured film.
Stain resistance is especially useful on floors where spills can otherwise penetrate porous concrete. A continuous epoxy surface improves cleanability.
Resistance claims should be verified against the actual chemical, concentration, contact time and temperature expected in service.

EARLY WATER RESISTANCE

Waterborne epoxy remains vulnerable to liquid-water exposure during early cure because carrier water may still be present and network conversion is incomplete.
ARADUR 39's fast cure can improve early property development, but severe washing or immersion should still be delayed until the validated cure period has passed.
Premature exposure can cause whitening, gloss loss or softening. These effects may diminish with drying, but repeated early exposure can compromise the film.
Low-temperature applications may require longer time before water service even when the product can chemically cure at 5°C.

RECOATABILITY

ARADUR 39-based primers and floor coatings should be recoated within a validated interval. Applying the next coat while the first layer remains chemically receptive can improve intercoat bonding.
After full cure, the surface can become harder and less reactive. Mechanical abrasion may then be needed before recoating.
Blush, dirt or other contamination should be removed before applying the next layer.
Recoat intervals change with temperature and humidity and should therefore be established for field conditions.

AMINE BLUSH

Amine-cured epoxy systems can develop surface carbamate deposits when reactive amines encounter atmospheric moisture and carbon dioxide.
Waterborne adduct chemistry can reduce some free-amine behavior, but cool and humid environments can still encourage blush.
Blush can interfere with gloss and intercoat adhesion. Any visible or suspected surface deposit should be removed according to the coating procedure before recoating.
Breathable concrete service should not be confused with accepting uncontrolled condensation during cure.

RHEOLOGY CONTROL

ARADUR 39 coatings can require rheology modifiers to control sag, settling and application feel. Horizontal floor coatings need different rheology from vertical walls.
Associative thickeners, cellulose derivatives, clays or other waterborne rheology technologies may be used where compatible.
Amine addition changes pH and ionic environment, so rheology should be measured after the complete two-component system is mixed.
Excessive thickening can reduce the good flow and high-gloss performance that characterize ARADUR 39.

PIGMENTS AND FILLERS

Pigments and mineral fillers can be incorporated into ARADUR 39 coating systems where dispersion stability is maintained.
Titanium dioxide, iron oxides, silica, calcium carbonate, barytes, talc and other materials can alter color, rheology, hardness and cost.
Mineral surfaces can introduce soluble salts or pH effects that influence waterborne stability. Raw-material consistency is therefore important.
High pigment volume can reduce gloss and change water-vapor transmission. Breathable floor systems should be tested as complete formulations.

DEFOAMING

Waterborne mixing can entrain air, and concrete substrates can release air from pores as a coating wets the surface. Both mechanisms can create bubbles or pinholes.
Appropriate defoamers and application technique can reduce defects. Applying a primer to porous concrete can also reduce outgassing into later coats.
Excessive defoamer can create craters or intercoat-adhesion problems, so dosage should be optimized.
Concrete temperature changes during cure can drive air out of pores. Application during falling rather than rising substrate temperature can sometimes reduce outgassing.

LOW ODOR INTERIOR APPLICATION

Very low odor makes ARADUR 39 attractive for indoor work where conventional solvent-borne epoxy would create strong odor and ventilation demand.
Examples include occupied commercial buildings, basements, laboratories and utility spaces where work may occur near other activities.
Low odor does not remove the need for ventilation because carrier water must evaporate and reactive amine aerosols should not accumulate.
Workplace exposure controls should follow the current SDS and application method.

ARADUR 39 VERSUS ARADUR 35-1

ARADUR 35-1 and ARADUR 39 are both waterborne polyamine-adduct hardeners, but their concentration and performance profiles differ significantly.
ARADUR 35-1 is typically around 51-55% solids with AHEW around 380 g/eq, while ARADUR 39 is around 49-51% solids with AHEW around 330-335 g/eq.
ARADUR 39 is particularly positioned for breathable concrete coatings, damp-surface adhesion, low-temperature cure and long pot life. ARADUR 35-1 is more broadly positioned toward waterborne primers and anti-corrosion systems.
They should not be substituted one-for-one because AHEW, viscosity and resin compatibility differ.

ARADUR 39 VERSUS ARADUR 36

ARADUR 36 is a much higher-solids waterborne polyamine adduct at approximately 79-81% solids with AHEW around 165 g/eq. ARADUR 39 contains much more water and requires considerably more wet hardener for comparable epoxy functionality.
ARADUR 36 is designed for high-solids coatings with good corrosion resistance and long pot life. ARADUR 39 emphasizes fast low-temperature cure, breathability and damp-concrete adhesion.
ARADUR 36 is also suitable with some waterborne resin dispersions, while ARADUR 39 is specifically not recommended with solid-resin dispersions.
These distinctions make resin architecture and substrate condition central to product selection.

ARADUR 39 VERSUS ARADUR 38-1

ARADUR 38-1 is another high-solids waterborne polyamine adduct, typically around 79-81% solids with AHEW around 150 g/eq. It is positioned for solvent-free high-solids coatings and high-gloss films.
ARADUR 39 has roughly half solids and a much higher AHEW, but it provides strong low-temperature cure and specialized breathable-concrete performance.
ARADUR 38-1 can be used with resin technologies for which ARADUR 39 may not be appropriate. Product choice should therefore reflect both resin compatibility and final coating function.
Direct replacement by wet weight would create severe stoichiometric imbalance.

QUALITY CONTROL

Important quality-control parameters for ARADUR 39 include appearance, Gardner color, solids, viscosity, amine value, density and active-hydrogen equivalent performance.
The product should remain a clear to slightly hazy colloidal solution without abnormal separation. Some haze is compatible with product identity, particularly after dilution.
Viscosity and amine value help confirm batch consistency. Solids verify concentration and therefore reactive-hardener delivery.
Functional cure testing with a standardized liquid epoxy resin can provide an additional application-level check.

WHY SOLIDS CONTENT MATTERS

Solids content directly determines the ratio of active hardener to carrier water. A lower solids value means more water and less curing-agent functionality per unit weight.
This changes mix ratio, drying time and film build. A higher solids value increases active concentration and usually increases viscosity.
Incoming quality control should therefore treat solids as a core parameter rather than a secondary descriptive value.

WHY AHEW MATTERS

AHEW connects hardener mass to epoxy functionality. ARADUR 39's approximately 330-335 g/eq value reflects the commercial product as supplied, including its water carrier.
Using a dry-solids AHEW in place of the as-supplied value would produce an incorrect mix ratio unless the calculation were adjusted carefully.
Published use levels already account for the commercial form and are therefore useful starting points.

WHY POT LIFE MATTERS

A long 3-4 hour historical pot-life profile can reduce material waste and provide time for floor application over larger areas.
Pot life is temperature dependent, and a warm mixed batch will react faster than a cool one.
Application quality should be monitored through the full window because viscosity alone may not reveal every change in cure state.

TDS, SDS AND COA

The current Technical Data Sheet or Enhanced TDS should be used to confirm present product properties, compatible resin guidance and application recommendations. explicitly warns that website information may not always reflect the latest document version.
The Safety Data Sheet governs formal hazard classification, component disclosure, first aid, firefighting, storage, transport and disposal.
The Certificate of Analysis provides batch-specific results for controlled properties where supplied.
Historical technical literature is useful for understanding product behavior, but current regulatory and specification decisions should rely on current supplier documents.

SAFETY AND HANDLING

ARADUR 39 is a corrosive reactive amine curing agent and should be handled according to the current SDS. warns that it can cause severe eye and skin irritation.
Do not allow the product to contact eyes, skin or clothing. Chemical-resistant gloves, protective clothing and suitable eye or face protection should be selected according to workplace risk assessment.
Mist and vapor should not be inhaled. Adequate ventilation is important during mixing and application, especially when spraying.
Containers should remain tightly closed when not in use and during transport.

SKIN CONTACT

Reactive amine hardeners can damage the skin and can contribute to sensitization after repeated exposure.
Contaminated skin should be washed promptly with mild soap and water according to handling guidance.
Solvents should not be used to clean skin because they can increase penetration and irritation.
Contaminated clothing should be removed and cleaned before reuse where appropriate.

EYE CONTACT

 first-aid guidance instructs immediate flushing with water for at least 15 minutes after eye exposure and immediate medical attention.
Because ARADUR 39 is corrosive, eye protection is essential during pouring, pumping and mixing.
Emergency eyewash facilities should be accessible in routine handling areas.

INHALATION

If mist or vapor is inhaled, guidance recommends moving the affected person to fresh air. Oxygen may be required if breathing is difficult under appropriate medical or emergency supervision.
Spray application can create aerosol even though the product contains no organic solvent.
Respiratory protection should be based on actual exposure assessment and the complete coating formulation.

INGESTION

ARADUR 39 is an industrial reactive chemical and must not be ingested.
 first-aid information indicates that a conscious person should be given plenty of water and immediate medical attention should be obtained.
Site procedures and the current SDS should govern the exact response.

SPILL MANAGEMENT

Spilled ARADUR 39 should be contained promptly. The aqueous viscous liquid can spread across floors and create a slip hazard.
Personnel should wear the PPE specified in the SDS. Suitable absorbent or pumping methods can be used depending on spill size.
Uncontrolled discharge to drains, soil or surface water should be prevented.
Recovered waste should be placed in appropriate labeled containers and disposed of according to local regulations.

FIRE RESPONSE

ARADUR 39 has a high flash point relative to solvent-rich curing agents, but the organic fraction can still burn or decompose when strongly heated.
Combustion can produce carbon monoxide, carbon dioxide, nitrogen oxides and other irritating or toxic fumes.
Firefighting media and respiratory protection should follow the current SDS and facility emergency plan.

STORAGE

Historical TDS information recommends storing ARADUR 39 in a dry place in the sealed original container at approximately 2-40°C and protecting it from direct sunlight.
Under those historical conditions the stated shelf life was approximately two years. Current supplier documentation and the expiry date on the package should govern present shelf-life decisions.
Containers should remain tightly closed to prevent contamination and unwanted changes in water content.
Material should be conditioned to appropriate processing temperature before accurate viscosity-sensitive dosing.

REGULATORY CONSIDERATIONS

ARADUR 39 is a proprietary industrial mixture. Regulatory status depends on all current components and the jurisdiction in which the product is used or placed on the market.
Zero-VOC positioning and absence of organic solvent are central technical claims, but formal compliance with a regional VOC rule belongs to the complete coating formulation.
Use in concrete floors or civil engineering does not automatically establish food-contact, potable-water or other specialized regulatory approval.
Current REACH, TSCA and regional inventory declarations should be obtained from current documentation when formal statements are required.

ENVIRONMENTAL CONSIDERATIONS

Waterborne and organic-solvent-free delivery reduces direct conventional solvent emissions from the hardener.
Uncured amine-containing material should nevertheless not be discharged directly to soil, sewer or surface water.
Cleaning water from epoxy operations can contain reactive resin, hardener, pigment and additives and should be treated as process waste according to local rules.
Fully cured epoxy has very different mobility and reactivity from uncured components, but disposal requirements remain jurisdiction-specific.

COMMON FORMULATION PROBLEMS

Poor coalescence with solid-resin dispersion
ARADUR 39 is specifically not recommended with solid-resin dispersions because cast films can show insufficient coalescence. Use a compatible liquid epoxy resin or select another hardener designed for the solid dispersion.

Slow physical drying
High humidity, weak ventilation, thick film or excessive water dilution can retain carrier water. Improve airflow and reduce unnecessary dilution.

Shorter-than-expected pot life
Warm material, catalytic pigments or highly reactive resin can reduce working time. Standardize temperature and formulation.

Haze after dilution
ARADUR 39 may become hazy when diluted toward approximately 30% solids. Uniform haze can be expected, but phase separation or coarse precipitation requires investigation.

Poor adhesion
Oil, dust, curing compounds, weak laitance or contamination can block contact with sound concrete. Correct surface preparation before reformulating.

Blistering
Excessive hydrostatic pressure, non-breathable topcoats or excessive film thickness can trap moisture. Evaluate slab moisture and complete system permeability.

Poor gloss
Rough substrate, foam, poor flow, pigment flocculation or incorrect drying conditions can reduce gloss. Optimize surface preparation and formulation.

Early water whitening
Incomplete drying and cure can cause whitening after water exposure. Allow the validated cure period before washing or immersion.

Foaming
High-speed mixing, porous concrete outgassing or incompatible surfactant balance can create bubbles. Optimize mixing and defoaming.

Sagging
Excess dilution or insufficient rheology can reduce vertical hold. Adjust water level and rheology modifier.

Low chemical resistance
Off-ratio mixing, incomplete cure or unsuitable resin can reduce resistance. Test the complete fully cured system under the intended chemical exposure.

Amine blush
Cool humid cure conditions can create surface deposits. Improve environmental control and clean the surface before recoating.

FREQUENTLY ASKED QUESTIONS

What is ARADUR 39?
ARADUR 39 is a waterborne modified polyamine-adduct epoxy curing agent supplied at approximately 50% solids in water.

Does ARADUR 39 contain organic solvent?
No. ARADUR 39 contains no organic solvents.

What is the solids content?
Approximately 49-51%, generally described as 50% solids in water.

What is the viscosity?
Approximately 12,000-20,000 mPa·s at 25°C.

What is the amine value?
Approximately 120-140 mg KOH/g.

What is the active hydrogen equivalent weight?
Approximately 330-335 g/eq as supplied.

What is the density?
Approximately 1.07 g/cm³ at 25°C.

What is the flash point?
Greater than approximately 93°C by closed-cup testing.

What is the reference use level?
Data give approximately 150-200 phr with ARALDITE GY 9708-3 resin.

Can ARADUR 39 be diluted with water?
Yes. it can be diluted down to approximately 30% solids, although haze may develop.

Can ARADUR 39 be used with solid-resin dispersions?
No.  that it is not suitable because cast films show insufficient coalescence.

Which resin type is preferred?
Liquid epoxy resins are preferred; current examples include ARALDITE GY 9513 and PY 340-2.

What is the typical pot life?
technical data describe a typical pot life around 3-4 hours.

Can ARADUR 39 cure at low temperature?
Yes. It is highlighted rapid cure around 5°C, and older technical data describe fast cure below 10°C with adequate ventilation.

Can ARADUR 39 adhere to damp concrete?
Yes. Current information highlights excellent adhesion to dry, damp or wet concrete.

Why is ARADUR 39 useful on damp floors?
It can be formulated into coatings with useful water-vapor transmission, helping reduce blistering caused by moisture pressure beneath the film.

What are its main applications?
Waterborne concrete primers, clear sealers, self-priming floor coatings, civil-engineering coatings and selected zero-VOC adhesive systems.

Is ARADUR 39 low odor?
Yes. It is listed low odor and older technical literature describes the product as very low odor.

Does ARADUR 39 have one CAS number?
No single CAS number should be assigned to the complete proprietary trade grade without confirmation from the current SDS.

How should ARADUR 39 be stored?
Historical guidance recommends sealed original packaging in a dry place at approximately 2-40°C, protected from direct sunlight.

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

FINAL TECHNICAL SUMMARY

ARADUR 39 is a waterborne modified polyamine-adduct epoxy curing agent designed for two-component ambient-cured coatings without volatile organic solvent in the hardener. The commercial material is supplied at approximately 50% solids in water and is principally intended for liquid epoxy resin systems.
Current product information lists excellent adhesion, fast cure, fast drying, high gloss, improved pot life, improved flow and low odor as major product features. Mineral substrates are the principal current compatibility category.
Published technical data specify approximately 12,000-20,000 mPa·s viscosity at 25°C, 120-140 mg KOH/g amine value, approximately 330-335 g/eq active-hydrogen equivalent, density around 1.07 g/cm³ and closed-cup flash point above approximately 93°C.

The product can be diluted with water down to about 30% solids, although haze may develop. Excess dilution increases the amount of carrier water that must leave the film and can slow drying or reduce film build.
A critical compatibility limitation is that ARADUR 39 is not recommended with solid-resin dispersions because the resulting cast films show insufficient coalescence. Liquid epoxy resins are the preferred technology.
Historical TDS information gives approximately 150-200 phr with ARALDITE GY 9708-3 as a reference use level. Current product information cites ARALDITE GY 9513 and PY 340-2 as examples of liquid epoxy resins suitable for zero-VOC fast-drying systems.

ARADUR 39 combines fast film cure with relatively long bulk working time. Historical technical data describe a typical pot life around 3-4 hours, while current positioning emphasizes rapid film cure at both normal ambient temperature and temperatures around 5°C.
Concrete is a particularly important substrate. Current information highlights excellent adhesion to dry, damp or wet concrete and describes the grade as well suited to primers and coatings with high water-vapor transmission.
This breathable-film concept is important on continuously damp floors because vapor pressure beneath a highly impermeable coating can cause blistering. ARADUR 39-based systems can reduce that risk when the complete coating architecture retains sufficient vapor transmission.

Current information specifically identifies self-priming concrete floor coatings and clear sealers as strong application areas and notes high chemical and stain resistance.
Historical product literature also lists water-reducible zero-VOC coatings, zero-VOC adhesives and civil-engineering systems. These applications remain chemically consistent with the product's waterborne polyamine-adduct character.
Fast drying below 10°C, very low odor, good flexibility, high gloss, good flow and good adhesion are all established characteristics in technical information.

Surface preparation remains essential despite damp-surface tolerance. Oil, dust, curing compounds and weak concrete laitance can still prevent adhesion to the actual mineral substrate.
Quality control should focus on appearance, solids, viscosity, amine value, color, density and functional cure performance. Slight haze is compatible with product identity, particularly after dilution, but gross separation is not.
ARADUR 39 is a corrosive reactive amine hardener. Current SDS instructions should govern gloves, eye protection, ventilation, first aid, fire response, storage, transport and disposal.

The commercial grade should not be assigned an invented single molecular formula, molecular weight, CAS number or EC number. Product-specific SDS documentation should control formal identity.
For ARADUR 39 technical specifications, application guidance, TDS, SDS, COA and formulation information, contact ATAMAN KIMYA with the intended epoxy resin, concrete condition, coating type and required service performance.

ATAMAN KIMYA
Phone: +90 216 577 10 10
Email: info@atamankimya.com