Simple Tape & Cross Hatch Adhesion Testing
How-To Determine if the Existing Surface is Well-Adhered to the Substrate
Published on
October 11, 2024 at 11:59:57 AM PDT October 11, 2024 at 11:59:57 AM PDTth, October 11, 2024 at 11:59:57 AM PDT
Adhesion Testing
Before painting self-storage roll-up doors or other surfaces with potential coating integrity issues it is often advisable to perform some adhesion testing. This article details to quick ways to do that. Note: for our purposes we are not using ASTM rated tapes with specific adhesion and tensile properties. These are quick 'pass fail' tests which can be easily performed in the field.
Perform A Simple Tape Test
One of the simplest tests you can do is a 'tape test' with duct tape.
- Apply a strip of high-quality general-purpose masking tape or duct tape to the area and several inches on either side, press firmly using a pencil eraser to press into grooves or valley if relevant to the area being tested. Leave a small portion of the tape available to grab onto.
- Remove the tape by pulling it off rapidly back over itself as close to a 180º angle as possible.
You can see from the tape pull that the paint is not adhered to the substrate.
Cross Hatch Adhesion Test
- Spray Windex over a 2” x 24” area
along the rib and valley.
- While the area is wet, use a Scotch-Brite pad to clean the door surface.
- Spray Windex over the surface and wipe dry with a clean, dry cloth.
- At several points on the door, especially where it looks like there might be problems, and at several different locations on the property, score through all layers of paint with a sharp utility knife in a right-angle lattice (checkerboard) pattern, 10 cuts in each direction, roughly 3/32” apart.
- Brush off any detached flakes of paint.
Next
- Apply a strip of high-quality general-purpose masking tape or duct tape to the area and several inches on either side, firmly press and rub into the valley and onto the rib sections. Then, using a pencil eraser, firmly rub the tape over the incisions to adhere the tape as securely as possible. Leave a small portion of the tape available to grab onto.
- Remove the tape by pulling it off rapidly back over itself as close to an angle of 180º as possible.
- Acceptable adhesion is 95%, as a small percentage of the paint will pull off where the door was scored. If whole squares between the score lines come off, then the coating has adhesion issues.
- Pull tests are not 100% foolproof. An example is latex paint applied on a glossy surface, which will generally adhere until it is wet.
- Comparing your results to the ASTM Adhesion Standards in the image below can be helpful.
If you compare the previous image with the tape pull to this chart This would rate a “2B” and would indicate moderate adhesion issues.
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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