Application Steps: Concrete release agents in precast plants
Manual Application of Release Agents
Producing high-quality precast concrete elements requires meticulous attention to a range of essential factors that directly impact the durability, appearance, and performance of each component. In standardized production processes, such as those for filigree slabs, concrete release agents are typically applied to formwork through automated systems, ensuring consistent coverage and minimizing waste. However, for more intricate or customized formwork, manual application of the release agent is often necessary. In these situations, achieving an even, effective coating requires a careful approach to formwork preparation and precise, controlled application of the release agent.
This page provides a comprehensive application guide that addresses common challenges and techniques in applying concrete release agents, helping you overcome potential issues with surface quality, adhesion, and product uniformity. The video tutorial to the left offers a clear, step-by-step overview of these instructions, making it an ideal training tool for team members involved in the manual application process. By following these best practices, you can ensure optimal release, protect your formwork, and achieve the desired surface finish in your precast elements, setting a foundation for quality and efficiency in every production batch.
Video tutorial coming Soon...
Before Starting: prepare the formwork
Dirt on the formwork reduces the effectiveness of the concrete release agent, making thorough cleaning essential. Begin by removing concrete residues and any other debris from the formwork. Larger adhesions can be efficiently removed with a steel brush or scraper, while finer dirt can be cleared with steel wool.
Once these materials are dislodged, ensure all dust and loosened concrete particles are removed. To minimize dust from sweeping, vacuuming the surface is recommended.
The cleaner the formwork before applying the release agent, the smoother and more consistent the concrete surfaces will be, significantly reducing the cleaning effort required after formwork removal.
Checklist: Essential Considerations Before Applying Concrete Release Agent
Applying release agent: this is how you should proceed
Release Agent Wax: Ideal for Complex Formwork Shapes
Certain precast concrete components require precise and complex shapes to meet specific design demands. For these cases, intricate formwork designs may include chamfer strips or integrated recesses in select areas. To ensure seamless release, even in challenging sections, the formwork should be pretreated with release wax. This additional step helps achieve smooth release and prevents damage to both the formwork and concrete surface in complex configurations.
How Much Release Agent Should Be Applied?
This is perhaps the most common question: what is the optimal amount of release agent to achieve the best possible results? Here, the principle is “less is more” rather than “more is better.” Over-application can actually worsen outcomes due to excess separating substances, leading to residue buildup on the formwork, which increases cleaning demands. Additionally, overuse may cause more pores and cavities in the concrete, requiring costly rework.
The instructions below provide guidance to help you achieve optimal application of the concrete release agent.
Avoid overdosing the release agent (e.g. puddles or streaks)
Has too much been accidentally applied? No problem! Simply wipe the formwork with a mop. After that, the formwork is ready for concreting.
Tip: The finger test as a simple release agent check
The ideal release agent application results in a glossy, not wet, oil film on the formwork, where the finger test leaves no visible marks; if the surface appears wet or shows finger traces, excess should be wiped away to ensure optimal concrete quality.
Key Application Tips:
- Use an oil-resistant sprayer with a stainless steel container, set at 4-6 bar pressure.
- Opt for a stainless steel flat spray nozzle (recommended: Spraying Systems TPU800067-SS).
- Apply a thin, even layer of release agent—remember, less is more!
- Avoid wiping if the release agent is applied correctly.
- If over-applied or uneven, simply wipe off the excess.
- Use release wax for complex shapes, chamfer strips, or recesses.