🟦 When to Use a Primer?
Why primers matter — and when you can skip them
In the world of industrial coatings, primers are often the unsung heroes of long-lasting performance. While some projects may not require a primer, knowing when to use one can be the difference between failure and flawless results.
This article breaks down exactly why primers are used, when you can skip them, and how to select the right primer based on your substrate condition and system needs.
🟩 Why Use a Primer?
Primers serve multiple purposes:
- Improve adhesion between the concrete and the topcoat
- Seal porous or contaminated surfaces to prevent delamination
- Block moisture vapor from rising through the slab
- Neutralize surface contaminants, such as oils or curing agents
- Reduce product consumption by eliminating surface absorption
Without a proper primer, the topcoat can lift, bubble, or fail prematurely — even if it’s the best coating on the market.
🚫 When You Can Skip a Primer
There are cases where primers aren’t necessary:
- The substrate is clean, dry, and well-profiled
- You’re using self-priming products specifically formulated for adhesion
- The system is designed as a single-layer build with no compatibility issues
- The surface has already been primed recently and is within recoat window
⚠️ Always verify with the manufacturer before skipping the primer — even small details like slab humidity or unseen contamination can ruin a job.
🧪 Situations That Require a Primer
Here are real-world scenarios where a primer is not optional — and the best MAGIECHEM product to use:
🔹 Oil-Contaminated Concrete Floors
Use: MAGIECHEM 565
Oily garages, mechanical rooms, or areas with historical oil spills need a specialty primer to bond properly. MAGIECHEM 565 is engineered to penetrate contaminated substrates, locking in residues and allowing your epoxy or polyurethane coating to adhere without risk of delamination.
🔹 Moisture Up to 5% RH in Concrete
Use: MAGIECHEM 5076
Moisture vapor transmission is a silent killer of coatings. MAGIECHEM 5076 acts as a moisture vapor barrier, ideal for slabs up to 5% RH. This prevents bubbling, pinholes, and coating lift while priming the surface for a perfect finish.
🔹 High Moisture or New Concrete (24h)
Use: MAGIECHEM 5087
For fast-track projects where you can’t wait 28 days for the concrete to cure, MAGIECHEM 5087 is the solution. It’s a high-performance MVB that can be applied as soon as 24 hours after the pour, handling 6%+ moisture with ease. Perfect for high-traffic sites that require fast return to service.
🔹 Polyaspartic Moisture Barrier Technology
Use: MAGIECHEM 975
MAGIECHEM 975 is a world-first innovation — the only moisture vapor barrier on the market based on polyaspartic chemistry with exceptional adhesion to concrete. Unlike traditional MVBs, it combines fast recoat times, resistance to moisture up to 5%, and compatibility with a wide range of coating systems, not just polyaspartics. It’s the ideal solution when both speed and moisture protection are non-negotiable.
🏁 Conclusion
Choosing the right primer is not just a technical detail — it’s the foundation of a successful coating system. Whether you’re dealing with oil-contaminated slabs, moisture challenges, or fast-paced construction schedules, MAGIECHEM offers engineered solutions that ensure lasting performance.
Need help identifying the right primer for your project? Contact our team for expert advice and product recommendations tailored to your surface conditions.
