Field Case: MS Clear Coat Lost Gloss After Three Months

A customer recently contacted our team about a cost-effective MS automotive clear coat. According to the customer, the clear coat had good gloss immediately after application, but the finish showed noticeable gloss loss approximately three months later.

Instead of immediately concluding that the clear coat itself was defective, we started reviewing the complete refinishing process.

What We Are Checking

Our technical team asked the customer to confirm several important application details:

1. What primer system was used?
   Compatibility between different layers of a refinishing system can affect long-term performance. Whenever possible, we recommend using compatible primers, basecoats, clear coats, hardeners, and reducers from a tested system.
2. Was the basecoat applied too heavily?
   An excessively heavy basecoat application or insufficient flash-off time may trap solvent underneath the clear coat. Continued solvent release can contribute to shrinkage and deterioration of the final appearance.
3. Was the correct amount of hardener used?
   A 2K clear coat depends on the correct clear coat-to-hardener ratio to achieve proper crosslinking. Insufficient hardener may prevent the coating from reaching its intended hardness, chemical resistance, and durability.
4. Was sufficient clear coat film thickness applied?
   Applying too little clear coat may reduce the protective film available for long-term weathering and gloss retention. At the same time, excessive film build can create other curing problems, so the recommended application specification should always be followed.
5. What thinner or reducer was used?
   This is another important factor we are investigating. Using unsuitable industrial thinner, low-quality lacquer thinner, or solvents commonly referred to in some markets as "banana thinner" instead of the recommended automotive reducer may affect leveling, curing, gloss, and long-term coating performance.

Why We Have Not Reached a Conclusion Yet

At this stage, we do not believe it is technically responsible to attribute the problem to a single cause without checking the complete application process.

Clear coat gloss retention is influenced by the entire refinishing system:

Substrate → Primer → Basecoat → Clear Coat → Hardener → Reducer → Application → Curing → Outdoor Exposure

We are continuing to communicate with the customer and review the application details.

Once the cause is better understood, we will update this case with our findings and the corrective actions taken.

Our Approach to After-Sales Problems

When a customer reports a coating problem, our first question is not:

"Whose fault is it?"

The more useful question is:

"Which part of the refinishing process caused the failure?"

Understanding the real cause helps the body shop correct the problem and also helps us improve our products, application recommendations, and technical support.