Professional Detailing2 min read

Solvent-Rub Resistance Is Not a Universal Full-Cure Test

A solvent-rub result describes resistance under a specified test. It does not automatically prove that a coating has reached every property required for service or that the same result applies to another solvent.

Updated · NANOLAB Knowledge

The key distinction

ASTM's public description of D5402 explicitly distinguishes solvent resistance from full cure. The buyer should therefore ask which solvent, procedure and acceptance criterion the coating manufacturer requires. A method name without those details cannot establish an installation release decision for an unrelated product.

Practical checks

  1. Confirm that the proposed method is applicable to the coating system.
  2. Record the specified solvent, evaluation and acceptance basis in the laboratory request.
  3. Keep the result separate from other release requirements in the product instructions.

Example

Illustrative example: a sample withstands the agreed rub assessment, but the product's instructions still require a later service-release time. The test observation does not cancel that requirement. The responsible technical party must determine how the evidence fits the complete cure and release process.

Scope and limits

Do not perform improvised solvent rubbing on a customer's coated vehicle. This guide does not supply a solvent, rub count or passing threshold for NANOLAB products. Use the current method and supplier guidance through an appropriately controlled testing process.

Related guidance

Technical references: ASTM D5402: solvent resistance using solvent rubs. These sources describe their stated methods or products; they do not certify NANOLAB products or establish compatibility with an unlisted surface.

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.

Professional Detailing2 min read

Scratch-Test Tip Geometry: A Load Number Is Not Enough

A scratch-test result should identify the tool geometry as well as the applied load. Different tips can create different contact conditions, so a load-only comparison is incomplete.