Coatings Specifications, Good, Bad or Ugly: Lou Vincent Q&A

By Alan Kehr
Published: September 21, 2017 | Last updated: March 31, 2022
Key Takeaways

Writing a proper coating specification involves myriad details that must be site specific, taking into account the environment where the painting will be done, structure life and performance aspects, what coating system to use, and much more. A new series.

Past president of NACE International Louis D. Vincent has 57 years of experience in the coatings industry and is a well-known teacher and the renowned author of classic reference manuals that have influenced corrosion professionals worldwide for decades.


Over the past six decades, the development of coating specification best practices has marched in step with the evolution of protective coatings, informed by lessons from the field across the spectrum of industries impacted by infrastructure corrosion.

In this introduction interview for the series, “What Makes a Great Coating Spec,” Vincent explores essential considerations for anyone tasked with writing a coatings specification.


Q: What is a coating specification?

A: Coatings specifications are somewhat similar to rainbows. They come in a kaleidoscope of colors, from brilliant after a fresh spring rain, to dull and drab at the end of a gloomy winter day. We have no control over rainbows, but we do have control over the quality of the coatings specifications we write. First off, we must understand the task involves details, details and more details. (For insight on some details, read Tightrope: Identifying Limiting Conditions for Coatings Specification.)

Q: Who is the specification typically written for and who uses it?

A: Writing a truly good coatings specification clearly describes what the owner expects in the way of aesthetics and durability of a structure, in order to issue a contract to have that specific structure painted.

It matters not what the structure is or where it will serve; the intent of the coatings specification is to clearly delineate the owner’s expectations.


In the case of a commercial building, the owner’s most critical expectation may be the brilliance of colors in the decorative scheme, whereas in the case of an offshore drilling rig or an FPSO (floating production & storage operation), the owner’s expectation may be that the FPSO will serve in a harsh, corrosive marine environment for a period of 20 to 30 years with a minimum of maintenance required.

In each case, the specification writer should become thoroughly informed about that structure and the owner’s expectations for the coatings program on that structure. This requires a substantial investment of research on the part of the specification writer, because despite the fact that two structures may be identical, the service environment can be dramatically different.


Q: What spec writing approach would you classify as bad?

A: Too many coatings projects wind up being classified as failures because the specification writer suffered from what is sometimes called “The Xerox Syndrome.” Simply stated, that means the writer takes out an old specification and changes the wording to reflect a new structure without really understanding the complexity of painting that structure in that specific location at that time of the year. (Learn more in Why it’s a Mistake to Reuse Old Coating Specs: Lou Vincent Q&A.)

Q: Is a lot of detail always required for coating specs?

A: With any coatings project, the devil is in the details. This does not mean that longer specifications are better than short ones. What it does mean is that the specification must thoroughly address the known complexities of that specific painting project.

On the other hand, that doesn’t mean that the writer has to create a deliberately complex, lengthy specification. The old adage, “How long should a person’s legs be?” is an appropriate analogy, with the answer being “Long enough to reach the ground.”

So how long and detailed should a coating specification be?

The answer is: Only as long and as detailed as is necessary to clearly establish what has to be done to prepare the structure for painting, what coating system has to be applied, and what criteria are necessary for successful completion of the project.

A good rule of thumb is that the more critical the coating system is to the expected performance of the structure, the more detailed the specification needs to be.

While it is important to include enough detail to ensure proper coating application, it is also necessary to avoid being overly detailed. Contractors are not lawyers; they need to know what is expected of them so they can organize the necessary equipment and manpower to meet the requirements of the specification and any governmental regulations that could apply in that specific location.

Specifications that try to pin everything down to a gnat’s eyebrow will only lead to excessive logistics prior to, during and after the coating project. Loss of time and poor manpower allocation are natural outcomes of an overly detailed coating specification.

Q: Is it always necessary to write a spec, or can the painting contractor simply apply the coating system in accordance with the coating manufacturer’s written instructions?

A: Is this appropriate? Is this adequate? The answer is a resounding NO.

Manufacturers cannot anticipate all of the complexities of structures, or the vagaries of the environments in which those structures will be painted, or where they will be placed into service. In order to sell their coatings over the largest possible market, often on a global basis, coatings manufacturers must base their recommendations on broadly generic conditions.

It is the coating specification writer’s responsibility to work with the coating manufacturer’s technical service department to fine-tune the broad recommendations to fit the specific requirements of each particular project.

Q: There are many chemistries and brands out there. How do spec writers select coatings?

A: At some point in the development of a coating system for a specific painting project, the specification writer must narrow the potential coating systems down to a manageable few, normally no less than three for each service area. This will be true unless the owner decides to have single coating source responsible for that project, which rarely happens unless there is a carefully worded warranty issued for that project.

Narrowing down potential coatings systems to a manageable few is often done in one of the following three ways:

  1. Using so-called legacy systems
    These are coating systems that have been successfully used over a fairly long period of time with good results on similar structures. There is a potential for failures with legacy systems because while the coating may have the same name and number as the one that previously performed so well, the product may have been changed due to environmental regulations such as VOCs (volatile organic concentrations), toxic metals restrictions (heavy metals such a lead, chromium, etc.) or the unavailability of a key pigment in the part of the world where the coating will be manufactured for that specific project. Once again, the specification writer must do his due diligence before making a final choice of any coating system.
  2. Comparative laboratory tested systems
    This involves subjecting potential coating systems to side-by side tests in a laboratory that is designed to replicate as closely as possible the service conditions that will be encountered in each particular project. While this gives the specification writer some valuable data, he must recognize that it is virtually impossible to replicate all the service conditions in a laboratory environment.
  3. Coating manufacturer case histories
    This can be very valuable, but it has its potential drawbacks. Once again, the specification writer must research these case histories to determine if they truly represent comparable service conditions. A coating system that performs great on a rig in the North Sea will not perform exactly the same on an identical rig in the Gulf of Mexico or the Middle East.

Q: How would you summarize this short introduction to coatings specification writing?

A: This article focuses on only a few critical aspects of what separates a good coating specification from a bad or ugly coating specification. There are many other aspects of a properly written coating specification that must be analyzed and organized on a “site specific” basis, which will be discussed for your readers in later interviews.

Experienced specification writers have extensive checklists that they go through on each project in order to make sure that what they specify truly meets the expectations of the owner and, even more importantly, is achievable by the skill level of the painting contractors at the site where the project will be painted.

More in the "How to Write a Great Coating Specification" series:

Why it’s a Mistake to Reuse Old Coating Specs: Lou Vincent Q&A
Who Participates in Selecting Equal Coating Products?
Condition Survey – The Backbone of a Good Coating Specification
Defining Service Requirements & Environmental Factors for Coating Specification
Defining Client Objectives for Coatings Specification
Methods & Pitfalls in Selecting Coating Systems for Specification
Tightrope: Identifying Limiting Conditions for Coatings Specification
Problems Caused by the Lack of Clarity & Definition in Coating Specifications
Writing Safety Into Your Coating Specification

Share This Article

  • Facebook
  • LinkedIn
  • Twitter

Written by Alan Kehr | Managing Consultant, Alan Kehr Anti-Corrosion, LLC

Alan Kehr

Alan Kehr has more than 40 years’ experience in the pipeline and reinforcing steel coatings industries, specializing in research and development of coatings, marketing, and technical service. Starting his career in the lab and field at 3M for several decades, Alan has since become world-recognized expert in fusion-bonded epoxy (FBE) and epoxy-coated rebar, now holding three patents for innovative FBE coating chemistries.

Related Articles

Go back to top