How comes only half of the mask gets fogged

[Sbiriguda]

I’ll give an update. I washed the mask in the dishwasher. Plain program together with the dishes and plain soap. It was fine but there was still a fogged spot on the very top right part of the lens. I believe it must have been some silicone dirt stuck on it. So I used again toothpaste not mild normal one with electric toothbrush and eventually it got perfect just like new

 

[John C. Ratliff]

I have really good results with J and J baby shampoo. Put on after my after dive gear rinse, let dry and rinse right in ocean/pool right before dive.

My wife, Chris and I now use a 1:10 ratio of Johnson and Johnson Baby Shampoo in water, in a $1.95 spray bottle we got at a Fred Meyer store. It works very well. Spray the inside, rinse once and use, and it stays fog-free for an hour.

SeaRat

 

[Michael Jastrzebski]

Trying this last method by FreeFlyFreak as my latest mask sure has defied all other methods...thanks!

In case you still have a problem .. just found out of the only sure method to get rid off the silicon coating on a brand new lens...
It was shown to me on the Truk Master liveaboard by the cruise director just last week.
My brand new Tusa mask defied all methods and was getting fogged like crazy.
He grabbed a cigarette lighter and moved the flame around the inner mask lens (you have to move around and be careful not to burn the rubber), the lens almost got black from the soot but it was easily washed off, and bingo, absolutely no fogging problem anymore.

 

[Andrew Dawson]

I was able to do well with a toothpase/baking soda mix scrub and rinse...followed by the magic eraser scrub and rinse. The magic eraser felt like it actually removed a coating tho.

 

[Angelo Farina]

For removing silicon, when a good treatment with toothpaste (and toothbrush) is not enough, you have to resort to professional anti-silicone degreasers, such as this one:
https://www.amazon.co.uk/Degreasing-Antisil-770-Body-1L/dp/B005C3WJY0

 

[Sbiriguda]

Eventually I was succesful in defogging the mask hahaha

What I still wonder is how it was possible that I got only one half of the mask fogged and not the other half too. The swimming cap I use in the pool is also made of a silicone material (I think), it might be the cap itself releases some silicone in the mask, but I don't really think this is likely and anyway it doesn't explain why only half of the mask gets fogged. That's still a mystery to me even now that I have solved the problem

 

[WithingU]

maybe the manufactory missed anti-fog procedure for the right len