Polyurethane sealing and welding mastic
Recommended for sealing and welding similar or dissimilar materials in construction and industrial applications. It adheres to most substrates, like ceramics, cement, glass, wood, etc. Can be painted with common paints.
- High resistance to mechanical stress
- High elasticity
- High resistance to UV radiation and moisture
- Excellent adhesion
- Easy application
Certifications / Evaluations
KRAFT JOINT PU 25 is a one-component sealant of polyurethane base in the form of a thixotropic paste, which when exposed to air it transforms into an elastic and cohesive mass. It is recommended for sealing and welding similar or dissimilar materials in construction and industrial applications. It adheres to most substrates, like ceramics, cement, glass, wood, galvanized sheets, etc. and it is suitable for sealing vertical and horizontal joints of high mobility. It can be painted with common paints..
How to Use
To ensure good adhesion, the surface must be dry, clean, and free of dust, grease, salts, rust, residues, blistered paints, etc.
- Cleaning with a wire brush and then by compressed air, if available, is recommended. Metallic surfaces should be degreased with KRAFT WHITE SPIRIT.
- To avoid soiling at the joint edges, apply a masking tape along but make sure to remove it immediately after sealing and before the material gets hardened.
- Apply on the joint using a handgun or an air gun. Cut the nozzle to an opening according to the sealing width. Smooth down the surface with a spatula while the material is still damp..
- The joint width should not be less than 5 mm or more than 50 mm. The sealing depth should be half the width for widths larger than 2 cm and almost equal to it for widths smaller than 2 cm.
- Where needed, the sealing depth should be adjusted with BACK FILLING (expanded polyethylene rope), to avoid the adhesion of the material to the bottom and thus to allow free following of expansions and contractions.
- If the depth is not suitable for the BACK FILLING placement, it is advisable to place a polyethylene film (RELEASE FILM) on the bottom to avoid adhesion.
- Cleaning: Clean the tools and product residues immediately with KRAFT WHITE SPIRIT. Once the material has been cured, it can be removed mechanically.
- Store the product in dry places, at a temperature between 5°C and 35°C and for a period of 12 months from its production date.