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When craters, poor wetting or an uneven surface appear after coating application, one reaction may be:
“Let's add more wetting or leveling additive.”
Sometimes this helps.
But increasing the additive before identifying the cause may not solve the problem.
This is because poor wetting, cratering and poor leveling are related surface problems—but they are not necessarily the same problem.
If the liquid coating cannot spread properly over the substrate, substrate wetting should be investigated.
If the coating initially spreads but localized depressions or exposed areas subsequently appear, other factors should also be checked:
A crater therefore does not automatically mean that the formulation needs more wetting agent.
Silicone-based wetting additives can modify surface behavior and help a liquid coating wet certain substrates more effectively.
They can be particularly useful when working with difficult-to-wet surfaces.
However, selection should still consider:
Resin system + waterborne/solvent-borne system + substrate + other additives + downstream process
rather than selecting a product simply because it is described as a silicone wetting additive.
Wetting focuses on whether the liquid coating can spread over the substrate.
Leveling focuses more on whether the coating surface becomes smooth and uniform during film formation.
So when a customer says:
“The coating surface doesn't look good.”
the next question should be:
Does it fail to wet, crater, show orange peel, leave application marks, or develop another surface defect?
The answer can lead to different additive directions.
A coating additive is only one component of the complete formulation.
Increasing dosage may affect wetting or leveling, but it can also influence compatibility, intercoat behavior, recoating or other finished-film properties.
A controlled dosage comparison is therefore more useful than simply continuing to add more material.
Final dosage should follow the product data and formulation testing.
Instead of asking only:
“Do you have a silicone additive for coatings?”
provide:
Waterborne or solvent-borne + resin type + substrate + current defect + current additive + application method + target improvement
This helps determine whether the starting point should be wetting, leveling, defoaming or another surface-control function.
Do coating craters always mean insufficient wetting additive?
No. Contamination, compatibility and other formulation or application factors can also contribute.
Are wetting agents and leveling agents the same?
Their functions can overlap, but they do not address exactly the same problem.
Does increasing silicone additive always improve the surface?
No. Dosage should be optimized through formulation testing.
Why can the same additive behave differently after changing the resin?
Because the additive interacts with the complete formulation.
What information is needed for a recommendation?
System type, resin, substrate, application method and the specific surface defect are useful starting points.
Application boundary:
The appropriate additive and dosage should be confirmed in the customer's actual coating formulation and application test.
