it keeps fogging..and fogging......

[Dread Pirate Roberts]

Crest is the best! If you use a mint flavored toothpaste, just be prepared to cry a bit during the first few dives. I use the flat of my thumb and press hard in tiny little circles until the whole inside of the mask is lathered. I do "taste" the mask to make sure I have all of the toothpaste off.

 

[erubic]

How many of you have scratched your lens with one of these abrasives or otherwise? I remember when I first bought my newest mask. I didn't have any product to use and the D.M. told me to use sand! worked good, and didn't scratch the lens a bit(sherwood magnum2)=. Is it really THAT easy to scratch the lens?

 

[coberry7]

Mmm, the mineralogy class is coming back to me.

Glass has a hardness of 7 on a scale of ten. (A diamond is a ten) Keep in mind it is a logarithmic scale. Sand is mostly silicon dioxide (Glass), so it can scratch glass masks if applied properly, but it is rare. Teeth are made of a mineral called, amazingly enough, Apatite (calcium Phosphate, I recall. I could be wrong on the chemical makeup.). Apatite has a hardness less than glass. From memory, and only memory, I believe it is less than 7 on the hardness scale.

Therefore, abrasives in toothpaste will have a hardness less than that of Apatite (to prevent us brushing our teeth down the drain), which has a hardness less than that of glass.

To make it simple, the abrasives in toothpaste cannot scratch glass. Much like an emerald cannot scratch a sapphire, which in turn cannot scratch a diamond.

If your mask lens is made of glass, toothpaste away! If it is made of plastic, be careful. No telling it the particular plastic that your mask lens is made of is hard enough to resist toothpaste abrasives, as the hardness of any particular plastic in a mask lens is difficult to know.

Again, I hope this helps.

Colin Berry

 

[erubic]

Good Answer Coberry7!!!!!!!!!! :35:

 

[coberry7]

I just reread Themenz post. Coatings can be of an indeterminate hardness. None of my masks (selected for my use by fit and visibility) have coatings of which I am aware.

I thought coatings were only applied to things such as binoculars and rifle scopes, maybe industrial glasses, skyscraper window panes, etc. Why not SCUBA masks?

Either way, those that make scuba masks know that we all know that toothpaste works to remove whatever it is that needs removal to prevent fogging of a new mask. (Why use a coating that almost all of there customers will remove immediately?) After this scrubbing, anything goes for keeping a mask from fogging at depth. There are too many variables to say what works in every situation.

Sea drops, shampoo, spit, and other commercial anti-fog stuff work well. It depends on you, your mask, and the diving conditions.

Colin Berry

 

[erubic]

In the encyclopedia of recreational diving it says:

"that most manufactures coat there new silicone and rubber products with a silicone-impregnated wax preservative. Unless removed this preservative may cause the straps to slip out of adjustment and prevent mask-defogging solutions from working. The first step in new equipment preparation is removing the wax preservative. Divers can scrub both sides of the mask lens and all the mask surfaces and fin straps with a nonabrasive cleanser or toothpaste."

 

[diverrick]

I tried the Fog-x first, but it did not work, then I tried dish soap, didn't work, I even tried Laquer thinner and rubbing alcohol to get the silicone off, didn't work. I finally used toothpaste and that did the trick. Go figure, after trying all the Tim Allenish ways to get it off, good old tooth paste did it! All I do now is to add a bit of anti fog just prior to going under, and I don't have any troubles. Old advice I know, just reinforcing it.

 

[bebo]

Mmm, the mineralogy class is coming back to me.

Glass has a hardness of 7 on a scale of ten. (A diamond is a ten) Keep in mind it is a logarithmic scale. Sand is mostly silicon dioxide (Glass), so it can scratch glass masks if applied properly, but it is rare. Teeth are made of a mineral called, amazingly enough, Apatite (calcium Phosphate, I recall. I could be wrong on the chemical makeup.). Apatite has a hardness less than glass. From memory, and only memory, I believe it is less than 7 on the hardness scale.

Therefore, abrasives in toothpaste will have a hardness less than that of Apatite (to prevent us brushing our teeth down the drain), which has a hardness less than that of glass.

To make it simple, the abrasives in toothpaste cannot scratch glass. Much like an emerald cannot scratch a sapphire, which in turn cannot scratch a diamond.

If your mask lens is made of glass, toothpaste away! If it is made of plastic, be careful. No telling it the particular plastic that your mask lens is made of is hard enough to resist toothpaste abrasives, as the hardness of any particular plastic in a mask lens is difficult to know.

Again, I hope this helps.

Colin Berry

The Mohs Scale of Relative Mineral Hardness
1. Talc
2. Gypsum
3. Calcite
4. Fluorite
5. Apatite
6. Feldspar
7. Quartz
8. Topaz
9. Corundum
10. Diamond
The Mohs scale is strictly a relative scale, but that's all that anyone needs. In terms of absolute hardness, diamond (hardness 10) actually is 4 times harder than corundum (hardness 9) and 6 times harder than topaz (hardness 8). Because it isn't made for that kind of precision, the Mohs scale uses half-numbers for in-between hardnesses. Dolomite, which scratches calcite but not fluorite, has a Mohs hardness of 3½ or 3.5.
http://geology.about.com/library/bl/blmohsscale.htm

 

[coberry7]

Thanks for the refresher. Time to go dust off that B.S. of Geology degree. Haven't used it in a while.

I had forgotten where Apatite fell on the scale, just that it is softer than glass. At a five, I am 100% certain that there is no abrasive in toothpaste that can scratch glass.

 

[Damselfish]

I don't think I've ever scratched a mask with toothpaste, but scratched one up with something once - it was either a non-scratch cleaning pad like for non-stick cookware (I keep a piece around to clean my slate) or a "non-scratch" kitchen cleaner of some sort. That was probably a really dumb thing to try. Messing up the glass with microscratches not only doesn't help vis but makes the glass fog worse, I figure it's creating nucleation sites for the little water drops to form or interfering with what no-fog is trying to do. I had to give up and get a new mask.