When making your mask, the manufacturer sprays the mold for the mask skirt with what is known as a releasing agent. This helps prevent the skirt from tearing when removed from the mold.
The problem is, despite the manufacturer’s best efforts to prevent it, some of this chemical remains on the mask skirt and leaches on to the mask lens. Unless removed, this and other chemicals involved in the manufacturing process can prevent your mask defog from working.
This is why your Open Water Diver course materials talked about the importance of thoroughly cleaning your mask’s lens prior to use. What some divers don’t realize is not only the importance of this step, but how much effort they need to devote to it.
1. To start, you need the right cleaning agent. Possible candidates for this include non-abrasive cleansers, toothpaste and dishwashing detergent. The best solution, however, is commercial products made especially for mask preparation. This is what we recommend.
2. Second, you need to follow the directions. If using a commercial cleaning agent read the directions and follow them precisely.
3. Third, you need to be willing to invest the time needed to do the job properly. Plan on spending anywhere from three to five minutes, and applying plenty of elbow grease.