Oceanic Shadow Mask Fogging Problem

[dsong9]

hey pescador77, by scurbbing in the toothpaste and vinegar, does it completely remove the film on the lens? And does that mean, even without spit, fog now won't form 'cos of the absence of the film?
Now from what it seems, toothpaste is used as an abrasive to scrub out the film on the lens. I don't quite get it when they say put toothpaste on your lens b4 your dive, then wash it off, kinda like saying toothpaste is a defogger?
So is toothpaste both and abrasive to remove the chemical film as well as a natural defogger for mask lens?

 

[pescador775]

OK, let's try to walk through these questions. This is a kind of kitchen science where we try things until it clicks. The problem with a new mask is unique, once that is taken care of, then all that's necessary is to spit and rinse before the dive. It appears that the factory glass has some kind of inert coating that cannot be removed with ordinary solvents. (Solvents act by turning a solid substance (the coating) into a liquid solution). That doesn't work but we know that a lot of elbow grease with various cleaners seems to get the job done. Most of these act by abrasion or a kind of detergent action which is technically different from what solvents do. It cannot be dissolved. However, we know it can be be broken up and removed. Rubbing certain kinds of toothpastes can thin out or scratch the film, microscopically. This prepares the job for the next step, breaking the bonds which hold the film in the micropores of the glass. Sometimes this takes an oxidizing agent like acid. That is why I tried white vinegar. One test doesn't make a rule, regrettably. It might be a reliable method but I can't say for sure. The reason we are trying to clean the glass is to expose the pores or microcracks in the silicon. Saliva is a unique substance. It contains anti microbial compounds and something called "surfactant". This substance has the ability to lower the surface tension of water and allow it to sheet on a piece of glass. It is more efficient than many man made chemicals like "defog". The "spit" remains in the micropores even after the mask is rinsed. It is God's gift to divers and some Asians (who spit for good luck).

 

[pescador775]

I'd better clear up one point. I didn't explain about drying and what was meant. "Spit washing" is wetting with saliva and rinsing. "Drying" can mean "shake out the water" or "wipe with absorbant cloth", or "let dry in the shade", and I didn't clarify which. I don't believe it is helpful to wipe out a mask after rinsing. Generally, a mask which has been (ahem) washed is good for the day. However, it is little effort to repeat the spit and rinse before each dive. A new mask is more likely to require it.

 

[Silvertip57]

Have used Softscrub and a toothbrush to get in all the cracks and crevices rinse very well and repeat the process. It generally takes about three scrubs to get the release agent off both the glass and the skirt and all the little nooks and crannies. Then just a spit and and rub keeps things nice and shiny down in the briny.

 

[Zeamonkey]

Carefully use a cigarette lighter and burn that film off the lens. It was the only thing that solved the foggin on my shadow. All the instructors at my shop use this trick. But be carefull not to burn the seal where it connects to the lens.

 

[freza]

Carefully use a cigarette lighter and burn that film off the lens. It was the only thing that solved the foggin on my shadow. All the instructors at my shop use this trick. But be carefull not to burn the seal where it connects to the lens.

zeamonkey, did it really work? 100% no more fogging? tried that, fog free for the 1st 20 mins (an improvement from 2 mins previously). then the fog started again...

i have the shadow black.