Explainer: Coating Technical Data Sheets

What is a coating TDS

A coating TDS, or technical data sheet, is a document produced by a coatings manufacturer. It states the technical properties of a product under defined test conditions. The sheet lists chemistry, film build, drying times, and performance expectations.

Readers often confuse a TDS with a Material Safety Data Sheet. The two documents serve different purposes. A TDS describes how the coating performs and how to apply it. An SDS or Safety Data Sheet covers health, safety, and disposal information.

When evaluating a supplier, the TDS is the primary technical reference. It does not replace a sales pitch. It does not guarantee performance on every substrate. It is a baseline for comparison and a starting point for site trials.

How to read the product overview

The product overview section identifies the coating family, binder type, and intended use. For example, a two-component polyurethane topcoat may be described for industrial maintenance. A waterborne acrylic primer may be listed for steel substrates.

Pay attention to the stated purpose. A product described for interior use may not have the UV resistance needed for exterior exposure. A coating rated for high temperature may use a different solvent system than a standard room temperature product.

The binder type matters. It affects flexibility, chemical resistance, and adhesion. If a TDS lists a flexible aliphatic polyurethane, expect better elongation than a rigid epoxy. If it lists a high solids acrylic, expect lower VOC and different drying characteristics than an oil-based alkyd.

Key performance data to check

Performance data is the core of the TDS. It tells you how the coating behaves after application. The following fields are common and should be reviewed carefully.

• Film build at application
• Drying or curing times
• Hardness
• Chemical resistance
• UV stability
• Adhesion strength
• Impact resistance

These values are measured under specific laboratory conditions. They are not a promise that the coating will perform identically on a production line. They are reference points.

A short table can help compare products side by side. The values below are illustrative formats only. Do not treat them as real product data.

Data Point	Typical Format	What It Tells You
Dry film thickness	Microns or mils	How much material remains after drying
Pot life	Hours or minutes	Time to mix and apply a two-component product
Wet on wet	Minutes to hours	How long you can apply the next coat
Hardness	Shore D or J	Resistance to surface indentation
Salt spray	Hours to failure	General corrosion resistance indicator

Salt spray results are often cited in hours to first sign of rust or to a specific percentage of substrate area affected. The standard used matters. Different protocols can produce different numbers for the same product.

Application and handling data

Application data tells you how to put the coating on the substrate. It includes substrate preparation, application method, and environmental limits.

Substrate preparation is often the weak link. A TDS may state that the substrate must be clean, dry, and free of oils. It may also list a required profile. For example, a surface profile of 3 to 5 mils may be needed for good adhesion to steel. If the profile is too smooth, the coating may not bite. If it is too rough, the film may look uneven.

Application method affects thickness. A spray gun, roller, or brush will produce different film builds. The TDS often lists a minimum and maximum dry film thickness per coat. Staying outside that range can cause problems. Too thin and the film lacks integrity. Too thick and the coating may sag or dry with solvent traps.

Environmental limits are critical. Temperature and humidity affect drying. A product with a narrow temperature range may need heated conditions. A high humidity limit may require dehumidification or a different product.

Safety, storage, and disposal

The safety section on a TDS is brief but useful. It lists the primary hazards and required protective equipment. It is not a full safety document. For that, you need the SDS.

Storage conditions affect shelf life. Some coatings require cool storage. Some are sensitive to freezing. If you store a two-component product in a cold area, the resin may thicken. The hardener may lose potency. Check the storage instructions.

Shelf life is usually stated as a time period under specific conditions. For example, a six-month shelf life at room temperature. Once opened, a can or drum may have a shorter use period. Always check the date on the container.

Disposal instructions are also listed. Coatings generate waste in the form of rags, filters, and empty cans. The TDS may state that the product is classified as hazardous waste in some regions. Local rules govern disposal. Do not assume all waste goes to the same bin.

How TDS data affects sourcing decisions

The TDS helps you compare suppliers on technical merit. It moves the conversation from price to performance. It also helps you plan the site trial.

When you have two products, compare them field by field. If one product has a longer pot life, it may be easier to apply on a large job. If another has higher chemical resistance, it may be better for a tank. The choice depends on the site.

Price is only one factor. A cheaper product with a short pot life may cost more in labor and waste. A more expensive product with a long shelf life may reduce inventory risk. The TDS helps you see these trade-offs.

Suppliers may provide different formats. Some TDS are one page. Others are multi-page documents with test data. Ask for the full technical package if the overview is sparse.

A worked example in plain words

Imagine you are sourcing a topcoat for a steel structure that will be exposed to rain and sun. You receive a coating TDS from a supplier.

The TDS states the product is a waterborne acrylic. The substrate is steel, prepared to a specific profile. The dry film thickness per coat is 40 to 60 microns. The drying time at room temperature is about four hours to the touch and twenty-four hours before recoating.

The performance section lists salt spray resistance and UV stability. The UV data says the color may shift over time. This is a normal expectation for many exterior coatings.

You compare this to another product. The second product is an oil-based alkyd. It has a longer pot life and a slower drying time. It may be easier to apply in cool weather. However, it has higher VOC and may not meet your emissions limits.

You also check the application section. The waterborne product requires a maximum humidity of 85 percent. If your site is in a coastal area, humidity may spike. You may need to schedule work in drier periods or use a different product.

The worked example shows how a TDS is not just a list of numbers. It is a set of constraints. You match those constraints to your site, your substrate, and your schedule.

Common mistakes when reading a TDS

Readers often skip the fine print. They look at the headline performance value and ignore the conditions. This is a common mistake.

Another mistake is assuming the TDS covers all substrates. A coating tested on mild steel may behave differently on aluminum or concrete. The TDS may list one substrate as primary and others as secondary.

Some TDS use vague language. Terms like “good” or “excellent” are not useful. Ask the supplier to define them. Request a test report if the TDS is ambiguous.

Finally, do not assume the TDS is current. Formulations change. A TDS from a previous year may not match the product you receive. Check the revision date. Keep the TDS that matches the lot number.

Final check before ordering

Before placing an order, run a short check. Read the TDS against your project requirements. Confirm the substrate type. Confirm the application method. Confirm the environmental limits. Confirm the performance data.

If anything is unclear, ask the supplier. A good supplier will answer questions. If the answer is vague, that is a signal.

Keep the TDS with your records. It will be needed for maintenance, troubleshooting, and future touch-ups. It is a working document, not just a sales tool.