by Lada Simek
A long time ago, when I was still teaching chemistry, Rob Weintraub, the owner of New York Scuba showed me a mask that he called ‘the mask from hell’. Neither the original owner, nor he himself, was able to clean it sufficiently to keep it from fogging. He offered it to me as a challenge. I like a challenge and having a small laboratory at my disposal, I thought this would not be a big deal.
There are two extremes of compounds based on their electron arrangement, polar and nonpolar. The rule is that like dissolves like. Polar substances attract and dissolve other polar substances, like alcohol and water. Nonpolar substances like wax do not attract water and dissolve in nonpolar solvents such as gasoline, paint thinner and oil. Since the silicone on the glass is similar in its chemistry to carbon and its compounds, I assumed it was nonpolar and all I needed was a nonpolar solvent to dissolve it and clean the mask. I took the mask to my lab and began experimenting. I did not use toothpaste because it had been tried before. The way that toothpaste works is that it contains an emulsifier (detergent) and a fine abrasive called diatomaceous earth. This consists of the skeletons of millions of microscopic animals which died and landed on the bottom of the ocean floor. I would bypass this gentle system and go to the heavy stuff, pure detergent and volcanic pumice as an abrasive. No effect!
Next I tried one of the most nonpolar substances I knew, carbon tetrachloride. This is a liquid formerly used in the dry cleaning industry, until it was found to be a pretty strong carcinogen and it is no longer available for public use. No effect!
Why not try alcohol? I sure did. I used methyl, ethyl and isopropyl. No effect! I tried ketones, acetone, butanone. No effect!
It was time to try the acids. Hydrochloric, with a pH of one had, you guessed it — no effect! Next I tried acetic acid. At 5% solution it is called vinegar, but I tried some 60% which smelled so strong it would knock a buzzard off a shit wagon. No effect!
THIS MASK HAS TO DIE! I had some concentrated nitric acid which is such a strong oxidizer it can start a fire on contact with organic substances. IT COULD DISSOLVE A PENNY IN 30 SECONDS! I tried it on the mask not caring if it will survive or not. No effect!
I ended up taking the mask back to Rob, who probably burned it at the stake. In the words of W.C. Fields: “If at first you don’t succeed. Try and try again. Then quit. No sense making a fool out of yourself.” NYC Escorts
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by Lada Simek
I am a former chemistry teacher, parachuting and scuba instructor, dive boat captain and senior director of Beneath The Sea as well as author about the marine world.
2 out of 9 got it right–you burn the lens. Burn it black, wash it out and see where it clouds up in ice water. Then reburn those spots. I haven’t ruined a mask yet (I did ruin a curtain trying to use a candle, but that is another story–about drinking mostly).
You approached the problem chemically – trying to remove a surface film based on its polarity. This makes sense as you call the problem “fogging”. As in typical problems of diver’s masks that have internal moisture condense on the inside of the glass lens. This develops over time against (relatively) colder glass from body-warmed moisture.
But what if the “fog” is there initially? It sounds like your mask from hell is not a condensation problem at all but a finely scratched surface problem. If it has a plastic film these are easily scratched by the fine abrasives in toothpaste. You say you did not try toothpaste because “it had been tried before?” In the words of Mythbusters – There’s Your Problem!
I would suggest the following for the lens: An abrasive buff used for cleaning dome ports – Fine 000-grade steel wool followed by Brasso. Buff away the Brasso and a clear lens results!
Incidentally this works wonders on gauges and compasses with scratched-up plastic protector lenses. Not that my gauges ever dragged through the sand and got scratched…
As a chemist, also I can tell you you have made the fog problem a moot point. By exposing the skirt to nitric acid (concentrated!? what were you thinking) the various plasticizers, stabilizers and UV blocks in the “rubber” part of the mask will be affected and you have shortened its life. If it is clear silicone, it will soon yellow. Any flexibility will get brittle much quicker than if it had no such exposer.
This of course is dependent on temp and exposure. You did not say if you dunked the mask overnight in conc. nitric acid or carefully applied it to the lens only. Or applied warm fuming nitric, or room temperature or cold. But as you say, at this point you were “not caring if it will survive or not”.
You also don’t say if the lens was glass, tempered glass, or plastic.
You should have tried one of those abrasive kits for de-fogging clouded automobile headlight lenses.
the lighter is the key. works every time.
haha! Great fun to read this!
I once brought a new mask on vacation. I tried toothpaste, commercial mask prep, and I can’t remember what else. By the second day I was keeping some water in my mask so I could swirl it around every 20 seconds to clear my mask. That night in the bar the DM took a butane lighter to it. No more fogging.
Did you try Piranha solution? I believe it is a mixture of concentrated sulfuric acid and 30% peroxide, but I would have to look it up to be sure. It is reputed to be excellent in removing organic material from glass and is used in laboratory for this purpose.
Your lucky to be alive!!! Have you tried dipping the mask in all the chemicals you mentioned? If that does not work , get some Jack Daniels, drink it down & forget about it….Cheers
Saliva?