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When I put a my cellphone on a table for charging, some drops of paraffin wax were laying there which I couldn't see. After some time during charging, heat melted the paraffin wax and it stuck on the rear camera lens of my Lenovo k6 Power.

I tried to wipe the lens with a special cloth especially used for cleaning my glasses, but it couldn't remove all the scratches/stains.

Please suggest any solutions.

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  • $\begingroup$ It'll dissolve in (USP, clear) mineral oil, or (non-pumice-containing) waterless hand cleaner. The 'special cloth' will just get contaminated, don't want that. $\endgroup$ – Whit3rd Apr 1 '17 at 8:14
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The first thing I would try is to re-heat the phone then try to wipe the paraffin off with your lens cloth. Paraffin wax typically melts between 46 and 68 °C (115 and 154 °F)$^1$. Assuming you don't have a good way to accurately heat the camera to this temperature, I would just repeat what you did to melt the wax in the first place; let the camera discharge it's battery and then recharge it. Once it has heated up, try wiping it off with the lens cloth.

Unfortunately, I have a feeling the above procedure alone may not be sufficient to remove all of the wax. It's worth trying because it's simple and safe for your phone. If that procedure does not remove all of the wax, the next thing I would try is using a solvent in addition to the heating. The wax should dissolve in diethyl ether$^2$, which is the primary component of most engine starting fluid products. You should be able to go to any auto parts store and purchase a can of starting fluid who's primary ingredient is diethyl ether (sometimes just called ether).

The first thing you will want to do with the ether is to verify that it does not attack the material holding/surrounding your lens. If the area around the lens is all metal and glass, you are safe and can skip this step. If the area around the lens is plastic (unlikely) then you will want to test a small area of the plastic to be sure it will not be dissolved or distorted in any way by the ether. Simply soak a corner of the lens cloth with the ether and touch it to the plastic. You have to be fast because ether evaporates very quickly. You might want to use a magnifying glass to look at the area that you whetted with the ether. If there is any change in the color or texture (you should feel the area with your finger), then you have to decide whether you want to proceed and risk ruining your camera. Again, it is unlikely that this will be a problem. I looked at some images of your phone model, and while there are some plastic parts to the construction, the lens assembly appears to be just metal and glass.

If you decide to proceed with cleaning the lens with ether, it should be a pretty simple, straight forward process. I would heat the phone by charging it as discussed above, soak a portion of the lens cloth with the ether-based starter fluid, and gently wipe the remaining wax from the lens. The lens glass and any metal surrounding it are impervious to the ether (and any other ingredients of the starter fluid), but avoid contact with any plastic components.

Given your problem as you've stated it and the make of your phone, I'm pretty confident that your camera lens can be thoroughly freed of the paraffin wax. Don't hesitate to ask for clarifications of anything I've said in the comments, and best of luck!

1) Kaye, George William Clarkson; Laby,Thomas Howell. "Mechanical properties of materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. Retrieved 25 October 2013.

2) Seager, Spencer L.; Slabaugh, Michael. "Alkane reactions". Chemistry for Today: General, Organic, and Biochemistry. Belmont, CA: Cengage. p. 364. ISBN 978-0-538-73332-8.

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    $\begingroup$ Who cares about the lens assembly (typically all metal, like you said)? It is the anti-reflective coating on the lens itself that can be damaged in the first place. Chances are it's ruined already. Then again, I totally support your idea of starting with the diethyl ether. Petroleum ether, maybe. Acetone, definitely no. $\endgroup$ – Ivan Neretin Mar 31 '17 at 21:39
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    $\begingroup$ @IvanNeretin , excellent point that I really didn't think about. I assume that's some organic polymer and like you said it may be too late as it is. I think if it were my camera, I would probably get it pretty hot and really try to go after it with the lens cloth. If that didn't work I'd figure I have nothing to loose and try ether as my first choice of solvent. I think I better edit that caution into my answer...thanks for the heads up on that oversight. $\endgroup$ – airhuff Mar 31 '17 at 21:51
  • $\begingroup$ @IvanNeretin , some quick internet searching seems to indicate that the overwhelmingly most common antireflective camera lens coating is MgF2 because of it's physical properties and optimal refractive index. Wikipedia also said that fluoropolymers are occasionally used, but that's the only mention I've seen of an anti-reflective coating other than MgF2, so the possibility of a solvent soluble coating may be a non-issue. I'm going to look into this a bit more before making any edits to the question. Any further thoughts you might have would be greatly appreciated. $\endgroup$ – airhuff Mar 31 '17 at 22:06

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