XS-Scuba Mask lens material - scratching?

[reefduffer]

I have an XS-Scuba gauge-reader mask, model MA280BS. About 40 dives with it, and I'm quite satisfied. In fact I recently bought a second one as a back-up, reasoning that if I need the magnifier to be comfortable diving, my backup mask ought to have one as well. That may now turn out to be a very good thing ...

I have a little bit of a problem with fogging, though. I decided that maybe I hadn't done a good enough job cleaning the release agent when I first got it, out of concern for the cemented lens construction. So yesterday I put on the iPod, got out the toothpaste, a basin of water, and a green scrub pad, the kind that is advertised as safe for teflon cookware coatings, and which we use on dishes and glassware all the time, and went to work on the older mask, the one I've been diving with.

The insert that came with the mask says "The mask lens is made of tempered glass ...". The lens itself says "TEMPERED CE".

After a half an hour of scrubbing, I stopped and rinsed the mask thoroughly, and let it dry. What I now have is the center of the lenses where I did most of the scrubbing is a fogged mess of scratches. In this state the mask could probably be used in an emergency, but if it can't be improved, I'll probably have to replace it.

I guess there are a few possibilities:
1) I'm doing the right thing, and have finally started to remove the target manufacturing residue. Another 8 or 12 hours of vigorous scrubbing will get me there. I'm dubious ...
2) The scrub pad + toothpaste scratches glass. Also dubious IMO.
3) The lens is plastic, contrary to the product description. Unlikely.
4) The glass lens has a coating (anti-fog?) that isn't mentioned in the product description, and that's what I'm scratching. Maybe ...

Could XS-Scuba comment on this? What has happened in my case?
Is recovery possible, and what should be done?

And what new-mask preparation process is recommended? Toothpaste?
Applied/rubbed with what?
Nothing at all is said about this in the product insert card, either as a recommendation or a warning.

Thanks.

 

[reefduffer]

And the winner is ...
2) The scrub pad + toothpaste scratches glass. Also dubious IMO.

I grabbed a bottle from the trash recycling and gave it the same treatment, a half hour or so with the same toothpaste and scrub pad on a small area of the bottle. I was surprised to discover that I'd scratched up the bottle with similar result to what happened to the mask! Not at all what I expected, but there it is.

If I have the patience, I may repeat separately with the toothpaste (Crest Tartar Protection fresh mint gel, fwiw) and the scrub pad, but my guess the culprit is the scrub pad, since the toothpaste seems like common practice.

So I'm out a mask, clearly nobody to blame but myself. My new spare just became my primary, and I guess LP gets another order for a backup. Live and learn. I hope I can save somebody else from trying this.

 

[Daiika]

reefduffer sorry to hear about your mask. I used the toothpaste, in fact the very same one you used. But I use my finger. I let it sit about 30 minutes then wash it clean. Usually it takes about 2-3 times then it won't fog. The best thing is to ask around, like on scubaboard or as many divers as you can find to ask. I even did the lighter trick. But on a $29 mask. Safe Diving.

 

[reefduffer]

reefduffer sorry to hear about your mask. I used the toothpaste, in fact the very same one you used. But I use my finger. I let it sit about 30 minutes then wash it clean. Usually it takes about 2-3 times then it won't fog. The best thing is to ask around, like on scubaboard or as many divers as you can find to ask. I even did the lighter trick. But on a $29 mask. Safe Diving.

Yup. I now have my 2nd GR mask, now my primary, quite clean. Used a soft rag, and around the edges, an old (no longer usable for dental hygeine) tip on my electric toothbrush. I'm very convinced the culprit was the green dish scub pad. It just never occurred to me it could scratch glass, but it does.

My third GR mask (new backup) should arrive from LP Monday. BTW, if you call them for a price, it's not that far from a $29 mask. LP rocks.

I did do some more searching here on sb on mask cleaning technique, and I found links to two excellent discussions which I'd strongly recommend:
SCUBA Knowtes, Your Dive Mask
Heavy Bubble: Mask Fog No More

The most useful thing I learned that I didn't already know (well, other than not to use a green scrub pad) was the trick of testing in cold water. In fact, I used a bowl of clean ice water kept in the refrigerator. After each session of toothpaste scrubbing, wash the mask thoroughly with dish detergent and several rinses under the tap. Then submerge in the bowl of icewater for 3-5 minutes (in the refrigerator).

Take it out, dry both sides of the lenses quickly with a clean towel, and then fog the inside with your breath as hard as you can. You can really see where the lens is clean and where it isn't; the effect is quite dramatic. I cleaned one side while leaving the other untouched, and the difference was like night and day. Being able to see the difference so dramatically adds positive reinforcement to getting the job done completely, and you can see the little spots that need just a little more work, instead of just scrubbing until you think you must have scrubbed enough.

In fact, when I showed my wife the left/right difference, she was so impressed, she got out her 6-year old mask she thought was clean and put it in the ice water, and that caused her to do her own toothpaste cleaning session, with very visible results.

 

[LKJ]

I know that this thread is old, but I came across it while looking for a solution to my similar problem. I just solved my mask scratch problem. I read somewhere that you can use white polishing compound with a felt buffing wheel to polish Perspex watch crystals, so I decided to try this on my mask lenses using a Dremel type rotary tool with a polishing wheel at medium speed. The tool melted through a plastic coating layer (anti-fog I assume), revealing tempered glass underneath. This coating was only on the inside of the lenses. I was then able to easily and cleanly peel away the remaining plastic with my fingernail, starting where the melted plastic met clean glass. My lenses are perfect now and I'll just have to use old fashioned spit or liquid defog now with the coating now gone.