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How to Read a Coating Product Data Sheet | Stop Guessing Before You Start Mixing Last Updated: 09/10/2026 |
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How to Read a Coating Product Data SheetStop Guessing Before You Start Mixing A coating can be expensive, highly engineered, and perfectly suited to the job—and still fail because somebody treated the Product Data Sheet like paperwork instead of instructions. The Product Data Sheet tells you what the coating was designed to do, where it can be used, how the surface must be prepared, how the material should be mixed, what equipment can apply it, how much film to build, and how long it needs to cure. Before opening the can the, opening drum, or connecting the pump, read the current Product Data Sheet. What Is a Product Data Sheet?A Product Data Sheet—commonly called a PDS, Technical Data Sheet, or TDS—is the coating manufacturer’s technical instruction document for a specific product. Depending on the manufacturer, it may contain information about:
The PDS answers: How should this coating be used? The Product Data Sheet Is Not the Safety Data SheetThe Product Data Sheet and Safety Data Sheet serve different purposes. Both should be reviewed before the coating is used.
The PDS cannot replace the SDS, and the SDS cannot replace the PDS. One helps you apply the product correctly. The other helps you understand and control the hazards. Step 1: Confirm That You Have the Correct DocumentBegin at the top of the document. Confirm the complete product name, product number, resin type, color or base designation, and revision date. Many coating families contain products with similar names but different hardeners, reducers, cure schedules, or application requirements. A data sheet for one version may not apply to another.
Do not rely on an old printed sheet simply because it is already in the shop. Formulations and instructions may change. Obtain the current document from the coating manufacturer or authorized supplier. Step 2: Read the Product DescriptionThe product description identifies what the coating is and what it was designed to accomplish. It may describe the coating as an epoxy primer, polyurethane topcoat, acrylic enamel, waterborne basecoat, lacquer, conversion varnish, zinc-rich primer, elastomeric roof coating, or another specific technology. Pay attention to descriptions such as:
These terms provide an overview, but they do not prove that the product is appropriate for every surface or service environment. Step 3: Confirm the Recommended UsesThe recommended-use section explains where the manufacturer expects the product to perform. Read it carefully and compare it with the actual job. Ask:
A coating that performs well on properly prepared steel may not be appropriate for galvanized steel, aluminum, plastic, concrete, or wood. “Paint” is not a universal instruction. Step 4: Find the Limitations Before They Find YouThe limitations section may be one of the most valuable parts of the document. It explains where the coating should not be used or identifies conditions that can reduce performance. Limitations may address:
A product’s limitations are not fine print. They are the boundaries of the job it was designed to perform. Step 5: Study the Surface-Preparation RequirementsA coating does not adhere to a specification. It adheres to the surface that is actually placed in front of it. The PDS may specify:
“Clean and dry” sounds simple, but it should never be interpreted as permission to ignore oil, wax, silicone, soluble salts, moisture, oxidation, sanding residue, or incompatible coatings. If the project specification requires more demanding preparation than the PDS, the conflict should be resolved before work begins. Do not quietly choose the easier instruction. Step 6: Understand the Mixing InstructionsTwo-component coatings depend on the correct relationship between the base and curing agent. Guessing, rounding, or adding “a little extra” hardener can change cure, flexibility, gloss, chemical resistance, color, and service life. Mix RatioThe mixing ratio may be stated by volume, weight, or both. These are not automatically interchangeable.
Do not convert a volume ratio to a weight ratio unless the manufacturer provides the required densities or a mixing table. Induction TimeSome catalyzed coatings must rest after mixing and before application. This is called induction time or sweat-in time. It allows the chemical reaction to begin under controlled conditions. If an induction period is specified, start the timer after the components are completely mixed. Pot LifePot life is the usable working period after components are mixed. Pot life is affected by temperature, batch size, and the specific coating. A mixed coating can sometimes appear sprayable after its stated pot life has expired, but appearance in the container does not prove that it can still cure or perform correctly. Never return mixed catalyzed material to the original unmixed container. Step 7: Read the Thinning and Viscosity InstructionsThe PDS may identify an approved reducer, thinner, water addition, or viscosity range. It may also give different recommendations for different application methods or temperatures. Confirm:
Excessive reduction may make a coating easier to atomize while producing insufficient dry-film build, runs, poor hiding, increased emissions, or reduced performance. If the coating is too difficult to spray, do not automatically reach for more thinner. Check material temperature, mixing accuracy, equipment size, fluid-delivery restrictions, and the manufacturer’s instructions first. Step 8: Match the Application EquipmentThe application section may list brush, roller, conventional air spray, HVLP, air-assisted airless, airless, electrostatic, or other approved methods. Spray recommendations may include:
These settings should be treated as a starting range. Final adjustment depends on the coating temperature, viscosity, equipment condition, part geometry, production rate, and required finish. Set up the equipment, make a controlled test spray, inspect the pattern, and verify the applied film. The data sheet does not eliminate the need for a spray-out. Step 9: Respect the Environmental ConditionsThe coating manufacturer may establish minimum and maximum temperatures for the material, surface, and surrounding air. The PDS may also provide relative-humidity and dew-point limitations. Check and record:
A warm room does not guarantee a warm substrate. A large steel part can remain cold long after the surrounding air has warmed. When the surface temperature is too close to the dew point, invisible condensation can interfere with adhesion and cure. Follow the exact temperature-to-dew-point separation required by the product instructions or project specification. Step 10: Understand Wet-Film and Dry-Film ThicknessFilm thickness is not a decoration. It is part of the coating system’s design. The PDS may provide:
Too little film may reduce hiding, corrosion protection, barrier performance, or service life. Too much film may cause solvent entrapment, sagging, cracking, wrinkling, incomplete cure, or loss of adhesion. Estimating Wet-Film ThicknessWhen no thinner is added, approximate wet-film thickness can be estimated from the desired dry-film thickness and the coating’s volume-solids percentage: Required WFT = Desired DFT ÷ Volume Solids as a Decimal For example, a coating with 50% volume solids applied to achieve 2 mils dry-film thickness would require approximately: 2 mils ÷ 0.50 = 4 mils wet-film thickness Added thinner increases the wet film required to leave the same dry film. Use the coating manufacturer’s calculation or instructions when the material is reduced. Step 11: Interpret Coverage Information CarefullyTheoretical coverage assumes ideal conditions with no loss. Real application includes waste from overspray, part geometry, surface profile, mixing containers, hoses, equipment cleanup, and material left in the system. Practical coverage depends on:
Do not use theoretical coverage as though every drop of coating will reach the part and remain there. Step 12: Separate Flash, Recoat, Handling, and Full CureThese terms describe different stages. They should not be treated as interchangeable.
Drying and curing times are commonly affected by temperature, humidity, air movement, film thickness, reducer selection, and ventilation. Step 13: Watch the Recoat WindowSome coatings may be recoated after a minimum flash time and before a maximum recoat time. If the maximum is exceeded, sanding, cleaning, or another preparation step may be required. The recoat window may change with temperature. A time printed for 77°F should not automatically be applied to a much colder or hotter surface. Record when application begins and ends. “Sometime yesterday afternoon” is not a controlled process. Step 14: Review the Cure ScheduleCure may depend on elapsed time, air temperature, humidity, substrate temperature, oven temperature, or time at metal temperature. For force-cured products, distinguish between:
A timer started when the oven door closes does not prove that a heavy part has reached the required temperature. Step 15: Check Cleanup and Storage RequirementsThe data sheet may identify the approved cleanup solvent, water-cleaning procedure, storage-temperature range, shelf life, and protection from freezing or excessive heat. Confirm:
Dispose of coating, solvent, water, filters, and contaminated materials according to applicable requirements. The PDS does not replace local environmental and waste-disposal rules. Turn the PDS Into a Job InstructionReading the document is only the beginning. The important information should be transferred into the shop’s work instructions, batch record, job traveler, or inspection form. Pre-Application PDS Checklist
Common Product Data Sheet Mistakes
When the Specification and PDS DisagreeA project specification, customer drawing, purchase order, internal work instruction, and manufacturer’s PDS may not always agree. Do not ask the applicator to choose which document wins. Stop and obtain a written clarification from the appropriate technical authority, customer, coating manufacturer, engineer, or specification owner. Document the decision and update the controlled work instructions before application resumes. The Applicator Needs the Information TooThe PDS should not live only in the quality office or on a manager’s computer. The person mixing and applying the coating needs clear access to the information that controls the work. A short job instruction should identify the details the applicator must control without requiring that person to search through several documents while mixed material is already aging in the pot. The Bottom LineThe Product Data Sheet is the manufacturer’s operating manual for the coating. It tells you what the product needs before it can provide what you expect. Read it before quoting the work. Read it before preparing the surface. Read it before selecting the equipment. Read it before mixing the material. The time to discover a coating requirement is before the material is mixed—not after the finished work begins to fail. Safety and Technical NoticeThis article provides general educational information. Always obtain and follow the coating manufacturer’s current Product Data Sheet and Safety Data Sheet. Follow applicable workplace procedures, equipment instructions, ventilation requirements, personal protective equipment requirements, fire codes, environmental regulations, and instructions from qualified safety and technical professionals. Do not mix, apply, heat, spray, store, or dispose of a coating based solely on this article.
AirSprayTech.com—The Finishing Authority® Tags:
coating product data sheet, paint technical data sheet, how to read a PDS, coating mixing ratio, coating pot life, wet film thickness, dry film thickness, volume solids, recoat window, coating cure time, paint application instructions
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