Yes, the surface has to be absolutely clean for our coating to work effectively. That doesn’t mean visually free of dirt. It means free of any surface contaminants at all (even the ones you can’t see). If a customer comes back to us having purchased a hydrophobic or oleophobic coating from us and explains that our coating isn’t working, it usually means one thing:
our coating is not being allowed to bond with the surface it was chemically designed for. Our Metal Repellency Treatment was chemically designed to bond with all types of metal, and it absolutely will if given the chance to. It was not designed, however, to bond with dirt, dust, oils, or organic contaminants. All of these must be removed prior to coating for the treatment to work.
This image shows the difference between a clean surface and a contaminated surface. Visually, the sheet of metal would look clean on both sides, however, the water tells a different story. The left side is contaminated with surface debris while the right side is completely clean. A surface must meet the water-break-free criterion to be ready for treatment. If the surface maintains an unbroken film of water, it is ready for coating. If there are breaks in the water, as on the above image, it is not clean enough yet.