Anatomy of a Self-Storage Roll-Up Door: What You Need to Know Before Painting
Surface Challenges, SMP and Manufacturer's Suggestions
Published on
August 15, 2024 at 2:19:00 PM PDT August 15, 2024 at 2:19:00 PM PDTth, August 15, 2024 at 2:19:00 PM PDT
A roll door consists of alternating vertical and horizontal surfaces. Over 20% of the surface area acts as a horizontal "shelf," where road grime and dirt can accumulate, and water tends to sit. This makes it particularly challenging to maintain and coat, as these areas are prone to increased contamination and moisture retention.The modern average 8-foot tall roll door has 26 ribs and 104 “corners.”
It is factory coated using a Silicone Modified Polyester (SMP) coil coating.
A Deeper Dive into “SMP” and Kynar Coatings
- SMP (Silicone Modified Polyester) and Kynar (Polyvinylidene Fluoride/PVDF) are the two most prevalent factory finishes for coil-coated steel used in metal buildings, metal roofs, roll-up doors, and similar applications.
- Kynar: Softer with better UV resistance, typically used in non-contact areas like roofs.
- SMP: Harder and more scratch-resistant, commonly used on doors and metal walls, but more susceptible to UV degradation and chalking.
- Both coatings are known to be equally challenging to repaint, with newer surfaces being particularly difficult to paint.
Let’s review the documentation provided by several commercially available "glossy surface primers" that specify their ability to be used over Kynar and SMP surfaces.
You’ll find several documents from popular commercial primer manufacturers, including those that specifically claim the ability to adhere to Kynar, SMP, and ‘slick and glossy’ or ‘tough-to-paint’ surfaces.
Note: These documents emphasize proper surface preparation, particularly for SMP. Their inclusion doesn't reflect product quality or suitability. Always follow the manufacturer's guidelines.
- BEHR Bonding Primer TDS
- Stix Waterborne Bonding Primer
- Zinsser Extreme Adhesion Primer
- XIM Primer Sealer Bonder
- Valspar Metal Building & Roof
- PPG Seal Grip
- Kilz Adhesion
- FixAll Grip Coat
- DTM Bonding Primer
- Extreme Bond Bonding Primer
Key Takeaway on “Glossy Surface Primer” Specs
- Surface Preparation: All sources emphasized the importance of a thorough cleaning system to remove surface contaminants, recommending the use of a degreaser.
- Chalk Removal: Removal of chalk was universally stressed as a critical step.
- Surface Characteristics: Horizontal surfaces and standing water were identified as particular concerns.
- Material Specifics: Both SMP and Kynar were singled out for requiring special attention, distinct from typical glossy surfaces.
- Surface Profiling: Strong recommendations were made for creating a surface profile (through sanding, dulling, or abrading) to establish a “mechanical” bond, enhancing the “chemical” bond provided by the primer.
- Environmental Conditions: All noted the importance of monitoring atmospheric conditions before, during, and after the application process.
- Testing: Test panels were universally recommended to ensure adequate adhesion before proceeding with the full application.
- Major Takeaway: This is one surface where taking shortcuts is like playing Russian Roulette.
Selecting the Right Product for Roll Doors
Chem-Bake is always our preferred and most robust system for coating SMP surfaces. As a solvent-based 2K system, it provides the best margin of error, but proper surface preparation remains essential.
Visit the Chem-Bake 1201 section for additional information. Click on any color to review supporting documentation at the bottom of each product page.
Product Recommendations
When to Use Chem-Bake
- If the surface has never been painted before.
- If it has been previously painted with a 2K urethane system.
- If it has been painted with a 1K silicone alkyd or an acrylic system with minimal issues.
- Especially if the surface has a slick, hard, smooth, or glossy finish.
Water-Based Systems:
- In our professional opinion, water-based systems, including Endura-Crylic, should only be specified if the project has been previously painted with a water-based system, and converting to Chem-Bake or another urethane system is not possible.
Disclaimer: All documents provided here are for comparative purposes only. Copyrights, trademarks, and brand names mentioned within these documents belong to their respective owners. No ownership or endorsement by the companies is implied.
Simple Tape & Cross Hatch Adhesion Testing
Adhesion testing is essential before painting surfaces like self-storage roll-up doors to ensure coating integrity. This article covers two quick methods: the Simple Tape Test and the Cross Hatch Adhesion Test. These tests assess paint adherence, identifying potential issues with paint bonding. Results can be compared to ASTM standards for evaluating adhesion quality, ensuring a durable finish.
Coil Coated Steel: Revolutionizing Self-Storage Construction
Coil coated steel is a versatile and durable building material widely used in the self-storage industry. This pre-painted sheet metal forms over 90% of structures, including roofs, walls, and doors. Commonly coated with silicone modified polyester (SMP), it offers excellent durability, UV resistance, and weathering. Its smooth surface can be challenging to repaint but ensures long-term performance.
SMP Prep for Refinishing Roll-Up Doors & Metal Panels
Properly preparing an SMP (Silicone Modified Polyester) coated surface is crucial for achieving a lasting finish. This guide walks you through the essential steps of cleaning and abrading your substrate, from pre-rinsing to applying Zap-It! and inspecting the final surface. Ensure your next painting or clear coating job is a success with these expert tips on substrate preparation.
Part Failure Part 2: Other Causes, Testing & Wrap-Up
There are a lot of reasons why paint fails. We'll wrap up a few other causes here and then cover solutions and other topics in subsequent articles. Aged Paint: When paint ages past its life expectancy, it becomes brittle and prone to failure. Recoating over such a surface increases the risk of peeling, cracking, or flaking, as the old paint may not adhere well. Proper preparation, including cleaning, sanding, and priming, is essential to ensure the new coating bonds effectively and lasts longer. We also touch on what can be done with a peeling paint job and wrap up with issues of worksmanship.ID#PF0001
Paint Failure Part 1: Diagnosing the Root Causes
Paint failures due to a variety of preventable issues can lead to substantial material and labor costs, and in some cases replacement of roll-up doors. Understanding why common problems like peeling, chalking, fading, cracking, and blistering occur is crucial for facility operators and painting contractors. By identifying the root causes of these issues, such as improper surface preparation, inadequate application techniques, or environmental factors, these paint failures can be avoided. For paint contractors implementing best practices can yield better results, and help avoid problems that can cost you both money and reputation. A variety of resources are provided to help diagnose and avoid common paint failure situations. These resources include guides, frequently asked questions, tips with images to diagnose the cause of a particular failure, and recommendations. ID#PF0001
Additional Reading
Self-Storage Roll-Up Doors: A Guide for Painters
This guide offers professional painters a comprehensive approach to evaluating, preparing, and painting roll-up doors using the Chem-Bake® system. It addresses the challenges of SMP coil-coated surfaces, provides tips on surface preparation, adhesion testing, and correct application techniques for achieving a durable, smooth finish on self-storage roll-up doors.
Part Failure Part 2: Other Causes, Testing & Wrap-Up
There are a lot of reasons why paint fails. We'll wrap up a few other causes here and then cover solutions and other topics in subsequent articles. Aged Paint: When paint ages past its life expectancy, it becomes brittle and prone to failure. Recoating over such a surface increases the risk of peeling, cracking, or flaking, as the old paint may not adhere well. Proper preparation, including cleaning, sanding, and priming, is essential to ensure the new coating bonds effectively and lasts longer. We also touch on what can be done with a peeling paint job and wrap up with issues of worksmanship.ID#PF0001
Paint Failure Part 1: Diagnosing the Root Causes
Paint failures due to a variety of preventable issues can lead to substantial material and labor costs, and in some cases replacement of roll-up doors. Understanding why common problems like peeling, chalking, fading, cracking, and blistering occur is crucial for facility operators and painting contractors. By identifying the root causes of these issues, such as improper surface preparation, inadequate application techniques, or environmental factors, these paint failures can be avoided. For paint contractors implementing best practices can yield better results, and help avoid problems that can cost you both money and reputation. A variety of resources are provided to help diagnose and avoid common paint failure situations. These resources include guides, frequently asked questions, tips with images to diagnose the cause of a particular failure, and recommendations. ID#PF0001
Disclaimer: The information provided in the Self-Storage Learning Center is for general informational purposes only. While we strive for accuracy, All From 1 Supply makes no guarantees regarding the completeness or reliability of the information. Use of this content is at your own discretion, and we encourage independent verification before making decisions based on the material.
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