Top Surface Prep Techniques for Long-Lasting Commercial Coatings

You can have the right materials with perfect weather and a skilled team - but if you don't prep your surface properly, you've done all the other work for nothing. Poor surface preparation is the leading cause of premature commercial coating failure and accounts for up to 80% of all failures. Skipping cleaning, drying, or profiling steps results in peeling, blistering, flaking, and rapid corrosion. These failures lead to costly maintenance, downtime, and reduced coating lifespan. Let's dive into the Top surface prep techniques to ensure longevity in your commercial coating application.

5 Key Steps to Surface Preparation

Assessment and Inspection - Identify existing contaminants, moisture levels, and structural defects like cracks or spalling.

Cleaning & Degreasing - Remove oil, grease, dirt, and salts using solvents, detergents, or steam cleaning.

Mechanical Cleaning & Repair -Repair any cracks and remove old, peeling paint, rust, or mill scale using grinders, wire brushes, or sanders.

Abrasive Blasting/Profiling - Create a surface profile (roughness) to allow the coating to anchor. You can do this by using sand or grit blasting. For spray foam on commercial roofs, you can use a scarfer to remove the foam and clear your substrate

Final Cleanup - Remove all dust and debris using vacuuming or oil-free compressed air before application.

Substrate - Specific Considerations: Before You Begin

• Concrete - remove laitance and contaminants. Ensure a 28-day cure time, or test for moisture and pH (needs to be~9). This will also be the time you will need to identify the CSP (or your Concrete Surface Profile)
• Steel - Requires abrasive blasting to remove mill scale and achieve a specific anchor profile. What are the location and climate conditions of the steel you will be coating?
• Existing Coatings - Must be sound; Remove peeling areas and feather current edges.
• Spray Foam - 

Power Tool Cleaning - When, Why, and What to Use

Power Tool Cleaning (SSPC-SP3) is a surface preparation standard requiring the removal of loose rust, loose mill scale, and loose paint from steel surfaces using power tools. It produces a cleaned surface where all contaminants that cannot be lifted with a dull putty knife are removed, but tightly adhered material may remain. SP3 is typically used for spot repair or when abrasive blasting is not possible. Result? The surface is free of loose, detrimental foreign matter, but differs from SSPC-SP 11, which requires producing a surface profile and removing all adherent material. Tools Used: Sanders, wire brushes, grinders, needle guns, and chipping hammers.

Other Standards:

• SSPC-SP 2 (Hand Tool Cleaning): Similar to SP 3, but SP 3 uses power tools for higher efficiency.
• SSPC-SP 15 (Commercial Power Tool Cleaning): More intense than SP 3, requiring a surface profile and removing all but 33% of tight stains per unit area

SSPC Standards - Prepping Your Surface

Surface preparation standards exist to maximize coating life and minimize costs. With surface prep accounting for up to 40% of the cost of a repainting project, facility owners look to limit the material and labor required for blasting. White Metal is expensive to achieve, especially on maintenance jobs, and is typically reserved for critical applications where the cost of failure would be catastrophic either financially or structurally. Get the full specifications at sspc.org.

SP 1 - Solvent Cleaning

Loosely-adhering material: 100%

Tightly-adhering material: 100%

Stains, streaks, shadows: 100%

Solvent Cleaning won’t remove all oil and grease – it just smears them over the surface, causing premature coating failure. Visible deposits of oil, grease, and dirt must be spot-cleaned before any abrasive blast cleaning.

SP 7 / NACE 4  - Brush Off Cleaning

Loosely-adhering material: 0%

Tightly-adhering material: 100%

Stains, streaks, shadows: 100%

Brush Off is specified to remove loose rust, mill scale, and coatings, and uniformly roughen up a surface in preparation for a new coat. Tightly-adherent materials are permitted to remain. Brush Off is specified where the expected life of the coating is short, such as ship hull anti-fouling, or in mild atmospheres and non-corrosive service environments, such as the exterior of a tank, in a rural location.

SP 14 / NACE 8 - Industrial Blast Cleaning

Loosely-adhering material: 0%

Tightly-adhering material: 10%

Stains, streaks, shadows: 100%

Industrial Blast Cleaning specifies that 90% of the tightly adhered matter must go. Shadows, streaks, and stains from rust, mill scale, and old coatings are allowed on 100% of the surface. Industrial is specified for conditions when the existing coating is thin, well-adherent, and compatible with the new coating.

SP 6 / NACE 3 - Commercial Blast Cleaning

Loosely-adhering material: 0%

Tightly-adhering material: 0%

Stains, streaks, shadows: 33%

Commercial Blast Cleaning specifies that all tightly adhering matter must go. Shadows, streaks, and stains can remain on up to 33% of the surface. Commercial Blast Cleaning is specified when a high degree of cleanliness is warranted. It’s common for repainting products that serve in non-corrosive environments and atmospheres, such as tanks and bridges.

SP 10 / NACE 2 - "Near White" Blasting

Loosely-adhering material: 0%

Tightly-adhering material: 0%

Stains, streaks, shadows: SP 10 5%, Sa 2 ½ 15%

Near White Blast Cleaning specifies that shadows, streaks, and stains must be extremely limited on the surface area (less than 5%). Near White is specified when the added benefit of blasting to White Metal doesn’t justify the added expense. Near White is typically specified for high-performance coatings over steel that will be exposed to severe environmental conditions, such as chemical spills and fumes, high humidity, and close proximity to salt water. It is commonly utilized for prepping offshore platforms, shipyards, and other marine environments.

SP 5 / NACE 1 - White Blasting

Loosely-adhering material: 0%

Tightly-adhering material: 0%

Stains, streaks, shadows: 0%

White Metal is the highest grade of abrasive blast cleaning. No shadows, streaks, or stains are permitted. When viewed without magnification, the surface shall be free of all visible oil, grease, dust, dirt, mill scale, rust, coating, oxides, corrosion products, and other foreign matter. White metal is used for steel serving under high temperatures, high pressures, and corrosive environments, and in cases where the consequences of coating failure justify the extra expense, such as nuclear reactors, turbines, chemical tank linings, submarines, etc.

Today, we covered so much information on surface prep, tool cleaning, and the main SSPC standards of blasting. We invite you to follow us on Facebook or Instagram to keep up with the latest Trail Sprayer & Service deals and informational blogs. Check it out: https://www.facebook.com/TrailSprayer/

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