Product Data Sheets Explained
How to read a coating product data sheet (PDS) — volume solids, coverage, film thickness, pot life, dry and recoat times, application limits and performance claims.
Key takeaways
- The product data sheet (PDS), also called a technical data sheet, is the manufacturer’s statement of what a coating is, how to apply it and what it can be expected to do.
- Volume solids, recommended DFT, mix ratio, pot life, dry and recoat times and application limits are the numbers applicators and inspectors use most.
- Most values are measured under stated laboratory conditions — usually a specific temperature and humidity — and change on site.
- The PDS is not the safety data sheet; use both, and resolve conflicts with the specification in writing before work starts.
Every industrial coating comes with a product data sheet. It is usually two to four pages long and dense with numbers, footnotes and conditions. Specifiers use it to select and specify products, estimators to calculate quantities, applicators to mix and apply correctly, and inspectors to verify the work. Reading it carefully prevents many of the problems later blamed on the coating.
The PDS describes performance and use. Hazards, PPE and exposure limits are on the safety data sheet (SDS). Many manufacturers also publish separate application guides for complex systems, which usually carry more detail than the PDS.
What a product data sheet contains
Layouts vary by manufacturer, but most data sheets include:
- Product description — generic type (for example, polyamide epoxy or aliphatic polyurethane), intended uses and key features.
- Physical data — volume solids, VOC content, colors, gloss, specific gravity, flash point and shelf life.
- Recommended film thickness — wet and dry ranges and theoretical coverage.
- Surface preparation — required cleanliness and profile by substrate, and compatible primers.
- Mixing and thinning — mix ratio, induction time, pot life, approved thinner and maximum thinning.
- Application — methods, equipment settings such as tip sizes and pressures, and environmental limits.
- Drying and curing — dry-to-touch, dry-to-handle, recoat intervals and full cure at several temperatures.
- Performance data — results of laboratory tests, sometimes with test methods and conditions.
- Disclaimers — statements limiting the manufacturer’s liability and noting that data are typical, not guaranteed.
Key properties and how to use them
| Property | What it means | Watch for |
|---|---|---|
| Volume solids | Percentage of the liquid volume that remains as dry film | Test method; values vary slightly by color |
| Recommended DFT | Dry film thickness range per coat | Minimum and maximum; exceeding the maximum can cause cracking or solvent entrapment |
| Mix ratio | Proportions of base and curing agent, by volume or weight | Whether partial kits may be mixed |
| Induction time and pot life | Waiting time after mixing; usable life of mixed material | Both shorten as temperature rises |
| Recoat interval | Minimum and maximum time before the next coat | Surface preparation needed if the maximum is exceeded |
| Application limits | Minimum and maximum air and surface temperatures, humidity, dew point margin | Stricter limits for some curing agents |
| VOC content | Volatile organic compounds, usually in g/L or lb/gal | Whether stated as supplied or after thinning |
Volume solids, coverage and wet film thickness
Volume solids links what goes on wet to what remains dry. Theoretical coverage is calculated as follows:
- US units: coverage (ft²/US gal) = 1,604 × volume solids (as a decimal) ÷ DFT (mils). A product with 80% volume solids applied at 8 mils (203 µm) DFT covers about 160 ft² per gallon in theory.
- Metric: coverage (m²/L) = volume solids (%) × 10 ÷ DFT (µm). The same product at 200 µm covers 4.0 m²/L.
The target wet film thickness is DFT ÷ volume solids, adjusted for thinner: WFT = DFT × (100 + % thinner by volume) ÷ volume solids (%). At 80% volume solids and no thinner, 8 mils DFT needs 10 mils (254 µm) wet. Practical coverage is always lower than theoretical because of overspray, surface profile, roughness and waste. See volume solids and coverage, wet film thickness measurement and the coverage and film thickness calculators.
Time-dependent properties
Pot life, dry times and recoat windows are usually given at one or more standard temperatures, often around 20–25 °C (68–77 °F), and sometimes at 50% relative humidity. Lower temperatures slow cure and lengthen intervals; higher temperatures shorten pot life and maximum recoat time. See mixing, induction time and pot life and recoat windows.
Copy the dry and recoat table for each product onto the job’s daily inspection form, alongside the actual temperatures recorded. It makes it easy to check whether each coat was applied inside its window.
Interpreting performance claims
Performance sections often list results such as salt spray hours, abrasion loss or adhesion values. Treat them with care:
- Check the method and conditions. A result is meaningful only with its test standard (for example ASTM B117 or ISO 9227 for salt spray, ASTM D4060 for Taber abrasion, ASTM D4541 for pull-off adhesion), the substrate, surface preparation, DFT and whether the test was on the single product or a full system.
- Do not equate test hours with service life. Accelerated tests rank coatings under specific conditions; they do not reliably predict years of service. See salt spray and cyclic corrosion testing.
- Compare like with like. Results from different manufacturers are comparable only if the tests were run the same way.
The PDS, the specification and the job
The specification usually requires work to follow the PDS while adding project-specific requirements. When the two conflict, raise it before work starts and get a written resolution from the specifier and the manufacturer. Contractors should also keep a copy of the PDS version in effect at the time of application, since data sheets are revised over time.
Using a thinner not listed on the PDS, or more thinner than allowed, can change cure, adhesion, VOC compliance and flammability — and may void the manufacturer’s warranty.
How to read a PDS before a job
- Confirm it is current. Check the revision date and that the product code matches the material delivered.
- Check suitability. Verify substrate, service and compatibility with the coats below and above.
- Extract the numbers. DFT range, volume solids, mix ratio, induction time, pot life, thinner limits and environmental limits.
- Calculate quantities. Use coverage and expected loss factors to order material.
- Plan the schedule. Use dry and recoat times at expected site temperatures.
- Ask questions. Contact the manufacturer’s technical service for anything unclear.
Frequently asked questions
What is the difference between a PDS and an SDS?
The PDS covers technical performance and application. The SDS covers hazards, safe handling, PPE, emergency measures and disposal in a standard 16-section format.
Why does the coverage on site never match the PDS?
The PDS gives theoretical coverage on a perfectly smooth surface with no losses. Real jobs lose material to overspray, profile, roughness, mixing waste and film builds above the minimum.
Are PDS values guaranteed?
Usually not. Most data sheets state that values are typical and subject to variation, and they include disclaimers. Specific guarantees come from warranties or contracts.
Educational reference. Coating performance varies by formulation. Always follow the manufacturer’s product data sheet, safety data sheet and your project specification.
