Flexible Cementitious Joint Filler

Flexible Polymer-Modified Cementitious Joint Filler

SEAL JF is a factory-proportioned, two-component polymer-modified cementitious compound developed for filling construction joints and cracks in concrete and masonry.

The powder and liquid components produce a smooth, workable mastic that can be applied across different types of construction joints. The cured material provides good durability, water resistance and the ability to accommodate dimensional changes.

SEAL JF is suitable for joints approximately 3–15 mm wide, including precast concrete joints, façade tile joints, dynamic floor joints, gypsum-board joints and natural-stone joints in internal and external applications.

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Properties

Technical Data

Properties

Property	Value
Type	Two-component polymer-modified cementitious joint filler
Appearance	Smooth mastic
Mixing Ratio	Factory proportioned
Mixed Density	Approximately 1.6 kg/l
Pot Life	Approximately 60 minutes
Initial Set	Approximately 36 hours at 23°C
Final Cure	Approximately 10 days at 23°C
Recommended Joint Width	3–15 mm
Recommended Width-to-Depth Ratio	2:1
Application Temperature	10°C to 40°C
Powder Packaging	20 kg paper bag
Liquid Packaging	8-litre container
Shelf Life	Minimum 12 months under recommended storage conditions

Technical Data

Uses

Filling joints between precast concrete elements.
Filling façade tile joints.
Filling dynamic floor joints.
Filling joints in gypsum boards.
Filling joints between natural-stone elements.
Filling construction joints and cracks in concrete and masonry.
Suitable for internal and external applications.
Suitable for joints approximately 3–15 mm wide.

Advantages

Two-component, polymer-modified cementitious system.
Accommodates dimensional changes.
Highly durable after curing.
Good resistance to water.
Smooth mastic consistency for easy application.
Suitable for joints approximately 3–15 mm wide.
Suitable for internal and external applications.
Ideal for hot-climate conditions.
Available in a range of special colors.
Factory-proportioned components for consistent performance.

Joint Preparation

All joint surfaces must be clean, dry, sound and free from dust, grease, oil, loose particles and any contaminants that may reduce adhesion.

Follow the correct joint design. For economical and effective application, maintain a joint width-to-depth ratio of approximately 2:1.

For façade tile joints, ensure that all tiles are firmly installed and that the tile adhesive has cured completely. Remove excess adhesive from the joints to provide a consistent filling depth.

Natural stone and unglazed tiles may absorb fine grout particles and become discolored. Test the mixed material on a spare tile before application and consult the tile manufacturer regarding the use of a suitable protective sealer.

Mixing

Use complete factory-proportioned packs whenever possible.
Place the liquid component in a clean mixing container.
Slowly add the powder component to the liquid while mixing continuously.
Use a slow-speed electric drill fitted with a suitable mixing paddle.
Mix for at least two minutes.
Continue mixing until a smooth, uniformly colored and lump-free consistency is obtained.

Application

Do not apply when the temperature is above 40°C or below 10°C.
Do not apply when the temperature is expected to fall below 10°C within 24 hours.
When required, prime the joint edges with a suitable WHITE SAND primer.
Remove any standing water before applying the primer.
Apply SEAL JF while the primer remains wet.
Fill the joint using a putty knife, pointing tool or suitable application gun.
Press the material firmly into the joint to ensure full contact with the sides.
Slightly overfill the joint to compensate for shrinkage during curing.
Finish the surface immediately after application.
When a smooth finish is required, use a suitable soapy solution during finishing.

Curing and Cleaning

Protect the freshly applied material from premature drying, contamination and mechanical damage during curing.

Clean tools immediately after completing the application using clean water. Hardened material must be removed mechanically.

Storage and Shelf Life

Both components of SEAL JF have a minimum shelf life of 12 months when stored in unopened and undamaged original packaging in a dry, shaded place, away from direct sunlight, at an ambient temperature below 35°C.

Packaging

Powder component: 20 kg paper bag.
Liquid component: 8-litre container.

Health and Safety

Wear suitable protective gloves and safety goggles during mixing and application.
Avoid unnecessary contact with the skin and eyes.
In case of skin contact, wash immediately with soap and clean water.
In case of eye contact, rinse immediately with plenty of clean, cold water.
Seek medical advice if irritation continues.
The product is non-flammable and is not classified as hazardous under current legislation.
Do not dispose of the material in water or soil. Follow applicable local disposal regulations.

Quality and Technical Support

WHITE SAND products are developed and manufactured under a quality-oriented product-development process and an independently certified quality management system.

WHITE SAND provides technical assistance regarding joint design, surface preparation, primer selection, product application and construction-chemical systems.