Proper surface preparation is essential to ensure optimal performance of Vetobond PB438 as a bonding agent or primer. All substrates must be structurally sound, clean, and free from contaminants that may impair adhesion, such as dust, oil, grease, laitance, loose particles, curing compounds, form release agents, or any other surface impurities. 

For cementitious surfaces, remove any weak or friable material by wire brushing, mechanical abrasion, or grinding. Blow or vacuum away all debris after surface cleaning. Glossy or smooth surfaces should be roughened to create a mechanical key, especially when applying to dense concrete or precast elements. 

In the case of highly absorbent or porous backgrounds such as AAC blocks, old plaster, or weathered concrete, pre-wet the surface thoroughly with clean water to achieve a saturated surface dry (SSD) condition. Avoid water ponding or excessive moisture accumulation.

Vetobond CP321 is supplied as a single component product ready to mixed on site. Shake or stir the container manually to eliminate any settled material. For larger volumes, mechanical mixing is recommended. Vetobond PB438 should be diluted with clean, potable water in accordance with the intended application. Use a slowspeed electric drill fitted with a paddle mixer operating at 300–400 rpm to ensure uniform blending without entraining excessive air. Continue mixing for 2–3 minutes until a consistent, lump-free solution is achieved.

Vetobond PB438 may be used either as a primer on porous surfaces or as a bonding admixture within cementitious mixes. 

It is recommended to mix the material in the same container before use.

For bonding applications, dilute 1 part Vetobond PB438 with 5 parts water by volume. The prepared solution can then be incorporated into the mixing water of cementitious mortars or adhesives. 

The prepared diluted solution (1:5 with clean water) should be added directly to the dry cementitious product (e.g., adhesive, mortar, render) during mixing. Apply the prepared mix onto the properly prepared substrate using standard tools such as a trowel or float.

For use as a primer or sealer, dilute Vetobond PB438 in the ratio of 1:10 to 1:20 by volume, depending on the substrate’s porosity. Mix thoroughly until uniform before applying with a brush, roller, or low-pressure spray. Ensure complete saturation, especially on porous substrates. Avoid pooling. Allow the primer coat to become touch dry before applying subsequent materials.

When Vetobond PB438 is used as a primer, ensure it is allowed to dry to a tack-free condition before applying subsequent layers. Do not leave the primed surface exposed for extended periods. For mixes containing Vetobond PB438, follow standard curing practices appropriate for cementitious materials. Protect from rapid drying, direct sunlight, and strong wind during early curing stages.

Clean tools with water before it hardens. Clean hardened residuals mechanically only.