ڤيتوفليكس بي يو 783

Vetoflex PU783 should be applied following proper joint design principles. The sealant must accommodate joint movement and adhere effectively to the substrate while preventing three-sided adhesion. A closed-cell polyethylene or polyurethane foam backer rod should be used to control the joint depth and provide a firm backing for the sealant. The backer rod must maintain a uniform, compression fit against both joint faces along its entire length.

Joint width and depth shall be designed in accordance with expected joint movement and accepted engineering practice. The minimum joint width should be 6 mm. For optimum performance, the joint depth should be approximately equal to the joint width for joints up to 12 mm wide. For joints wider than 12 mm, the depth should be maintained at approximately half the joint width.

Tool the sealant immediately using a suitable spatula or tooling device to ensure proper compaction, good adhesion, and a smooth surface finish. Remove masking tape before skin formation.

The sealant cures by reaction with atmospheric moisture. Skin formation and curing rate depend on ambient temperature and relative humidity. At 25ºC and 50% relative humidity, the curing rate is generally 2 – 3 mm per day. Protect freshly applied material from water, dust, and mechanical disturbance until fully cured.

Damaged or deteriorated sealant should be completely removed and replaced. Cut out the affected area and ensure joint faces are clean and properly prepared before reapplication of Vetoflex PU783. Partial repairs are not recommended where adhesion failure has occurred.

Remove Vetoflex PU783 from tools and equipment with Vetonit Solvent XX400 immediately after use. Wipe off any excess uncured material from the substrate using the same solvent. Hardened material can only be removed mechanically.

• Do not apply on wet or contaminated surfaces.
• Do not apply during rain or when moisture is present on substrates.
• Not recommended for continuous water immersion.
• Avoid contact with bituminous or tar-based materials.
• Adhesion and compatibility tests are recommended prior to full application.

All joints and bonding surfaces must be structurally sound, clean, dry, and free from dust, oil, grease, old sealant, and any traces of contaminants that may impair adhesion. Concrete and cementitious joint faces shall be mechanically prepared by grinding, wire brushing, or sandblasting to obtain a clean, sound, and open-textured surface. Loose particles must be removed using oil-free compressed air. 

If water flushing is required, it must be performed in one direction only to minimize contamination. After drying, the upper 25mm of each joint face should be sandblasted separately, with the nozzle positioned at an angle no greater than 50mm from the surface. 

Non-porous substrates such as glass, aluminium, steel, ceramics, and plastics should be cleaned using a suitable solvent such as Vetonit Solvent XX400 and wiped dry using a clean, lint-free cloth. Painted surfaces must be firmly adhered and lightly abraded prior to application. 

For joint sealing applications, insert a suitable closed-cell polyethylene backer rod to control joint depth and prevent three-sided adhesion. Where backer rods cannot be used, apply bond-breaker tape. Joint edges may be masked to obtain a neat finish. 

For bonding applications, ensure mating surfaces are properly aligned and prepared to achieve full contact and optimum adhesion.

Priming is generally not required on sound, clean, and dry substrates. However, for porous or highly absorbent substrates such as concrete and cementitious surfaces, the use of a suitable primer is recommended to enhance adhesion. 

On non-porous substrates, primer is normally not required. However, the surface must be clean and dry before applying the sealant. Where doubt exists, adhesion tests are recommended prior to application.

Before applying Vetoflex PU783, a masking tape should be placed along the joint edges to ensure clean, precise lines and prevent excess sealant from spreading onto adjacent surfaces. 

Next, position an appropriately sized backer rod into the joint, ensuring a tight, compression fit against both joint faces, to accurately control the joint depth and maintain uniform sealant thickness. 

Vetoflex PU783 is supplied ready for use and should be applied using a manual or pneumatic caulking gun. Cut the nozzle to the required bead size and apply the sealant continuously into the joint, ensuring full contact with joint sides. Avoid air entrapment during application.