Non-Wetting Troubleshooting

This phenomenon happens when either something is on the surface or a previous coat has not dried. The next coat cannot “wet” the surface so the finish pulls or puddles and will not flow out. This phenomenon may be caused by the following factors:

  • Fish-eyeing.
    • The first example of fish-eyeing is caused by applying a coating over something with a low surface tension. Wax, silicone, and soap are all examples of substances with very low surface tensions, which is why virtually nothing coats over them.
      • § Another example of this can be moisture, condensation and/or dew. Moisture can form on the substrate when there are climatic changes and/or differences in temperature. With high humidity or dew, a light film of water can be on the surface from sweating or chilling.
    • The second example of fish-eyeing is caused by little needle-like objects (e.g.: dirt, lint, hair) on the surface being coated. This is the electrical pull away from an object (Faraday principle). This is why a dirty surface will look like it’s fish-eyed as the coating pulls away from the dirt.

  • The previous coat of finish is not dry.
    • If the finish is beading up on top of a previously applied coat of finish, this may also be due to the previous coat not being dry enough. Dry time is affected by ventilation, humidity, temperature, species of wood, and scope of the project (Please review the drying, curing and ventilation project help link at the top of the FAQ page.) Immediately remove the newly applied coating with a rag dampened with mineral spirits and allow the coating to dry/cure completely. Compare our drying, curing and ventilation guide with your project and make changes to help cure the finish. When the coating is dry, begin with your next coat – we recommend waiting a minimum of 48 hours.

  • Old, improperly stored or overly oxygenated product.
    •  If an older or overly oxygenated can of finish is used after it was not stored properly, it can gain viscosity and slightly gel inside the can. The material may apply okay with the first coat, but will pull away on the second coat.
    • Mix the remaining material at 10% with mineral spirits and test an area to determine if it will wet and flow the surface prior to completing the whole project with the material.

In summary, a wetting problem is when, either, 1, something is on the surface of the previous coat, such as: humidity/condensation, residual solvent or contamination that won’t let the next coat lay down and flow out. Or, 2, the material being used is an older or overly oxygenated product that was not stored properly and has thickened/increased in viscosity.