NOVASTAR™ powder defoamers help formulators manage unwanted entrained air in cement- and gypsum-based dry-mix systems. Screen P805, P806 and P807 for self-leveling compounds, repair mortars, grouts and other applications where wet density and surface appearance matter.
Powder defoamers are solid-form additives incorporated into factory-prepared dry blends. During wet mixing they become available to disrupt unstable foam and help reduce excess entrapped air. Performance depends on the full formulation, not merely the powder’s physical appearance.
| Published reference | P805 | P806 | P807 |
|---|---|---|---|
| Listed application environment | Alkaline systems | Neutral / acidic systems | Low-temperature conditions |
| Bulk density | 500 ± 100 g/L | 500 ± 100 g/L | 500 ± 100 g/L |
| Particle size | 80 mesh | 80 mesh | 80 mesh |
| Moisture content | ≤ 5% | ≤ 5% | ≤ 5% |
| Reported pH value | 6–8 | 6–8 | 6–8 |
| Published dosage reference | 0.1–0.3% | 0.1–0.3% | 0.1–0.3% |
Grade selection starts with the mortar environment. The labels below describe LANDU’s published starting positions, not confirmed performance rankings. Two products with the same powder density or nominal dosage may behave differently in different surfactant, polymer and binder packages.
First shortlist for cement-dominant alkaline mixes such as self-leveling compounds, cementitious repair mortars and grouts.
Trial priority: air reduction after mixing, density, flow and finishing without destabilizing the mix.
Reference option for formulations with neutral or acidic working environments. Confirm that this matches the actual pH of the wet blend.
Trial priority: compatibility, foam breakdown rate, storage condition and the presence of defoamer-sensitive polymers.
Listed for lower-temperature conditions. This is a formulation screening direction, not a guaranteed all-season performance specification.
Trial priority: compare performance at realistic water, material and ambient temperatures, while tracking setting and spread.
High-shear mixing, surfactants, polymer dispersions and air-entraining constituents can introduce or stabilize gas bubbles in wet mineral mortar. A powder defoamer is formulated so that an active defoaming component becomes available upon wetting and can destabilize foam films. This may promote coalescence or release of excess bubbles during mixing, spreading or placement.
Lower entrapped air can increase measured wet density and reduce certain surface defects in suitable formulations. The magnitude and direction of change depend on mixing energy, wetting conditions, other admixtures and the intended air content.
A defoamer is not a replacement for a PCE dispersant or a viscosity modifier.
Some mortars are engineered to retain air for workability or other functional requirements.
Do not infer that LANDU P805–P807 contain a specific polyether, silicone or oil without current composition documentation.
Reduce unwanted foam accumulation in selected dry-mix mortar systems under defined mixing conditions.
Help limit pinholes and cratering related to entrained air, where air is a verified cause of surface defects.
Support formulation development toward a specified wet-density window, rather than pursuing minimum air indiscriminately.
The following scenarios are differentiated by application behavior and performance priorities. NOVASTAR™ supplies a functional additive, not a ready-to-use mortar, waterproofing system or guaranteed finished-formulation recipe.
Flowable flooring systems can trap air during high-shear mixing and spreading. Visible pinholes, craters or a porous surface can affect subsequent finishing. A powder defoamer can help control excessive entrained air while retaining the formulation’s required flow.
What to verify: compare wet density, spread/flow retention, surface pinholes and segregation. Verify that foam reduction does not disturb leveling or setting.
Explore self-leveling additives ↗
In cement-based waterproofing mortars, entrapped air may create visible discontinuities or reduce surface uniformity. Defoamer screening should consider the binder, redispersible polymer powder, surface application method and mixing energy.
What to verify: surface continuity, wet density, workability and application-relevant water-resistance testing. Defoamer use alone does not establish watertightness.
Explore waterproof mortar additives ↗
Repair mixes require workable consistency, adequate consolidation and sound contact at the repair interface. Excess air can contribute to voids, but aggressive deaeration may also change trowel feel and density.
What to verify: controllable air reduction, application thickness, finishing, bond testing and cracking sensitivity under the intended curing regime.
Explore repair mortar additives ↗
Flowing grouts and selected injection mortars may need limited entrapped air for better filling behavior. Effective foam control should be evaluated together with bleeding, particle settlement and pumpability rather than only bubble count.
What to verify: wet density, flow time, bleeding, filling performance and the final mechanical properties required by the specific grout system.
Discuss grout additive selection ↗
Gypsum-based smoothing compounds and decorative finishes can show pores or surface craters after mixing and application. The right powder defoamer depends on the gypsum chemistry, admixture package, mixing sequence and desired working time.
What to verify: surface smoothness, wet density, spread, setting behavior and finish quality. Check whether the selected grade is suitable for the actual pH and temperature.
Explore gypsum application additives ↗Choose the powder defoamer against the complete formulation. A product that reduces air in one cementitious mix may change flow or surface wetting in another, particularly when RDP, cellulose ethers, PCE and surfactants differ.
Record cement/gypsum binder, filler grading, polymer admixtures, water ratio and actual failure mode. Differentiate a true air-related pinhole from bleeding, contamination or insufficient wetting.
Use P805 for alkaline-system screening, P806 for neutral/acidic systems and P807 when low-temperature behavior is central. Confirm with the current TDS.
Compare a control against at least two sensible dosage trials, using the same batch size, water source, mixing sequence, shear and rest time.
Record wet density, spread/flow, bleeding or segregation, surface pinholes and the relevant final-product performance. Select for balance, not for the lowest air figure.
PCE changes particle dispersion and flow; some systems still require separate foam control. Evaluate both together because a change in dispersant can alter air entrainment and the perceived defoamer response.
See NOVASTAR™ PCE ↗Cellulose ethers influence water retention and rheology, while RDP contributes polymer modification. These ingredients affect mixing and bubble stabilization; test the combined additive package before grade approval.
See ACCURATE™ RDP ↗Technical diagnosis should isolate the air-control variable before changing the dosage or supplier grade.
Check: whether the pinholes originate from entrained air, premature surface skinning, substrate absorbency or contamination. Trial a grade/dosage change only after controlling mixing and curing conditions.
Check: air-content contribution using matched batches, then review powder dispersion, water dose and sand/filler changes. Confirm target density reflects the intended mortar, not a generic benchmark.
Check: simultaneous changes in PCE, mix-water ratio, mixing time or defoamer level. Excess defoamer may disrupt wetting or make the apparent consistency different.
Check: the balance between density, rheology and aggregate stability. Removing too much stabilizing air can expose a weak suspension structure.
Check: residence time, pumping shear, entrainment points, temperature and whether the additive retains useful activity through the entire process.
Check: order of addition, powder premixing, water temperature, mixer geometry, mixing energy and hold time. Repeat with representative production materials.
Technical purchasing decisions are strongest when suppliers and customers agree on an application-specific test matrix. Compare the control mix and modified mix after identical preparation, and document the endpoints that matter for the finished product.
ASTM C185 addresses air content of hydraulic-cement mortar under its defined method; it is not a universal acceptance criterion for every self-leveling, gypsum or polymer-modified product. Use a method appropriate to the specific formulation and governing standard.
LANDU supports inquiry-stage comparison with technical documentation and product sampling. Please confirm sample availability, packaging, minimum order quantities and current commercial terms with the sales team before placing an order.
Obtain grade-specific data for P805, P806 or P807 and verify specification methods, storage recommendations and regulatory documentation relevant to your market.
Share binder chemistry, application and defect descriptions. Trial material should be screened under the customer’s own production-relevant conditions.
The existing LANDU page lists 25 kg bags and 600 kg pallets; validate available pack formats, current lead time, batch traceability and CoA expectations with sales.
Concise answers for formulation engineers, technical purchasers and distributors.
A powder defoamer is intended for dry-blend handling and dosing before water is added. A liquid defoamer may be dosed into aqueous production streams. Suitability depends on the additive’s delivery form, dispersion, storage stability and wet-formulation behavior.
No. Reducing excessive entrapped air can influence density and some mechanical properties, but strength also depends on binder chemistry, water content, curing, aggregate packing and the complete mix design. Verify finished-product properties in controlled testing.
P805 is the published starting option for alkaline systems. Compare it against the control at the application’s actual water temperature, PCE level and mixing conditions; request current TDS for grade-specific limitations.
P807 is listed by LANDU for low-temperature environments. Its effectiveness at a specific temperature is not established by the published reference alone, so confirm the temperature range and run practical trials before specifying it.
The original LANDU page lists 0.1–0.3% as a dosage reference for all three grades, but does not specify the denominator or test system. Confirm the basis of this percentage and establish the appropriate level by application-specific dose-response trials.
Yes. Unnecessary air removal or incompatible defoamer selection may change flow, destabilize a mixture or impair the finish. Test minimum effective dosage along with wet density, spread, bleeding and any relevant downstream properties.
No. Defoamers address excessive entrained air. PCE primarily modifies dispersion and flow, cellulose ethers help control rheology and water movement, and RDP contributes polymer modification. These functions can interact but are not interchangeable.
Specify target mortar application, binder/filler system, other admixtures, mixing method, temperature, observed foam-related issue, current dosage and desired test result. This makes grade recommendations and sample evaluation more relevant.
Tell us whether you need to limit pinholes, adjust wet density or improve finish consistency. Include your binder system and mixing conditions to request a relevant NOVASTAR™ P805, P806 or P807 TDS and sample.
