filters Issue

Coating Adhesion Problems

When paint doesn't stick, there's always a reason. Here's how to find and fix adhesion failures.

What You're Experiencing

Applied coatings are not adhering properly to the substrate, leading to peeling, flaking, or delamination.

Visual Signs:

  • Paint peeling or lifting at edges
  • Flaking or chipping
  • Coating easily scratched off
  • Delamination between coat layers
  • Tape test failure
  • Blistering under coating
  • Coating sliding or wrinkling during cure

Sound Signs:

  • Crackling sound when coating flexes

Safety Risks — Read Before Proceeding

high

Product failures in field

Action: Adhesion failures mean coating won't protect the substrate. Don't ship defective parts.

medium

Customer complaints and warranty claims

Action: Address root cause before it affects more production.

medium(OSHA 1910.134, OSHA 1910.107)

Rework chemical exposure

Action: Stripping and recoating increases chemical exposure. Use proper PPE.

Immediate Steps to Take

  1. 1

    Stop production and save samples of failed parts

  2. 2

    Review surface prep procedure—was it followed?

  3. 3

    Check for contamination sources (gloves, handling, air)

  4. 4

    Verify coating is correct for substrate

  5. 5

    Check cure parameters (temp, time)

  6. 6

    Review booth conditions during application

  7. 7

    Perform adhesion test on recent production

Common Causes

Here are the most likely reasons you're experiencing this problem, ranked by how often we see them.

Surface Contamination

common

Oil, grease, silicone, wax, or other contaminants on the surface preventing coating bond.

Inadequate Surface Prep

common

Surface was not properly cleaned, abraded, or primed before coating application.

Wrong Product for Substrate

occasional

Coating system is not compatible with the substrate material (plastic, galvanized, etc.).

Insufficient Cure

occasional

Previous coat or primer was not fully cured before topcoat, or final cure was inadequate.

Booth Conditions

occasional

Temperature too low, humidity too high, or contamination from booth affecting adhesion.

Intercoat Adhesion Failure

occasional

Recoat window exceeded or incompatible products used between coats.

Interactive Diagnostic Tool

Adhesion Problem Diagnostic

Step 1 of 5

Is adhesion failing at the substrate (bare metal showing)?

If unsafe at any point: If adhesion failure is widespread, stop production and call WERCS at (877) 489-3727 for process evaluation.

When to Call WERCS

While some issues can be resolved with basic troubleshooting, these situations require professional service:

  • Cannot identify adhesion failure cause
  • Multiple products or batches affected
  • Need process improvement help
  • Booth contamination suspected
  • Customer complaints about adhesion
  • Need adhesion testing equipment

Priority Service Available

(877) 489-3727

Expert technicians nationwide

Coating Adhesion Problems FAQ

Common questions about this issue

The crosshatch tape test (ASTM D3359) scores a grid into the coating and applies tape. The amount of coating removed indicates adhesion quality. 5B (no removal) is best; 0B (over 65% removed) is failure. This is a standard QC test for coating adhesion.
Use water break test for cleanliness (water should sheet evenly). Measure surface profile for adhesion-critical applications. Follow coating TDS exactly. Document surface prep steps. When in doubt, do more prep—it's cheaper than rework.
Common causes: exceeded recoat window (previous coat too hard), contamination between coats, incompatible products, insufficient flash time, or wrong film build. Follow the coating system manufacturer's guidance for multicoat applications.
Yes. Cold parts cause condensation (moisture barrier). High humidity can affect some primers. Contaminated air deposits on parts. Poor exhaust allows overspray fallback. Proper booth conditions are essential for good adhesion.

Have a question not answered here?

Call us at (877) 489-3727

Related Parts & Components

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