Preparing for Success: Why Proper Surface Prep Is Essential for Any Polyurea Application

At UMI Coatings, we know that a polyurea system is only as strong as the surface it bonds to. Even the highest-performing coating cannot overcome poor preparation. Durable adhesion, long-term performance, and consistent results begin long before the first pass of material; they start with a disciplined, methodical approach to substrate preparation. 

Whether you’re coating concrete, metal, or another industrial surface, following proper preparation standards ensures your polyurea system performs the way it was engineered to. Below, our team outlines the four core steps involved in preparing a substrate for polyurea, along with practical guidance we share during contractor trainings and technical support visits. 

1. Clean the Surface Thoroughly 

Every successful application begins with a clean substrate. Contaminants like oils, dust, release agents, and residues can create a barrier between the coating and the surface, weakening adhesion from the start. 

We recommend using a surface cleaner or any cleaner approved by UMI Coatings. Continue wiping until your cloth or towel is completely clean. If residue remains, continue cleaning with solvent. This step prevents contamination from being embedded into the substrate during abrasion, which can compromise both adhesion and long-term performance. 

Key goal: A surface free of debris, oils, and residues before abrasion begins. 

2. Abrade the Surface to Create a Profile 

A mechanical profile is essential for giving polyurea something to “bite” into. Abrasion increases surface area, removes weak or damaged material, and creates the anchor profile needed for strong mechanical adhesion. 

Contractors can achieve this through multiple methods: 

• Scotch-Brite pads 

• Abrasive sanding with a dual-action sander 

• Abrasive blasting 

At UMI Coatings, our standard blasting media includes a combination of aluminum oxide and garnet, but other appropriate media types may also be used depending on the substrate and project conditions. 

Key goal: Abrade to the recommended AMPP standard to establish a consistent, clean, and well-defined surface profile. 

3. Clean the Surface Again After Abrasion 

Once the surface has been abraded, it must be cleaned a second time to remove dust, spent media, and contaminants uncovered during abrasion. Even the best blast profile can be compromised if residual particles remain. 

This step can involve: 

• Air cleaning (compressed, oil-free air) 

• Chemical cleaning with approved solvents 

A properly cleaned, abraded surface ensures the primer can wet out, seal, and adhere as designed. 

Key goal: Ensure no dust, debris, or contaminants remain after profiling. 

4. Prime the Surface for Strong Adhesion 

With the substrate fully cleaned and prepped, the final stage is priming or converting the surface. UMI Coatings recommends Defender Prime, applied to the appropriate film thickness for the blast profile. A deeper profile requires more primer to fully coat peaks and valleys. 

After application, allow the primer to cure until it passes the fingernail scratch test, indicating it is ready to receive polyurea. 

This step locks the surface, enhances adhesion, and provides a uniform foundation for the coating system to perform at its highest level. 

Key goal: Apply primer to the correct thickness and ensure proper cure before applying polyurea. 

Why Proper Surface Prep Matters 

Surface preparation is more than a checklist. It is a critical investment in performance, longevity, and client satisfaction. When done correctly, proper prep: 

• Prevents delamination and premature coating failure 

• Maximizes adhesion between the substrate and coating 

• Ensures uniform coating performance across the entire surface 

• Supports long-term durability in demanding conditions 

At UMI Coatings, we emphasize these fundamentals in every training session and technical support visit because they truly determine the success of the system. 

Partnering with UMI Coatings 

Our team is dedicated to helping contractors, applicators, and facility managers get the job done right. From prep to application, we provide hands-on training, on-site guidance, and product expertise designed to support your success in the field. 

If you have questions about substrate preparation, primers, or choosing the right polyurea system, our team is here to help.