Strongest solution advisable for cleaning lens exterior (casing)?

Gogl · 13 Feb 2014 at 15:23

I have an inexpensive Sigma lens and it looks like the aperture lock has been glued by something akin to nail varnish, I don't know why people do these things but anyway if I can clean it off I'd rather do that than return it as it was part of a lot. I think it may be fine and was just put on to keep the aperture at f22.

Can I ask what the strongest cleaning solution is that would be ok to use on the exterior? I'd likely just apply it to the end of a cotton bud, but I don't want to end up using something that would damage the plastic, or perhaps affect any adhesives used in the lens.

Any thoughts much appreciated.

lord filbuster · 13 Feb 2014 at 21:36

Isopropyl alcohol is likely your best bet, it shouldn't harm the lens. You can get it off ebay or a spray can of electrical contact cleaner from halfords.

Nail polish remover (acetone) should still be ok, but only as a last resort. Acetone can damage certain plastics, but it should be ok if you only use a little bit for a short time.

Gogl · 13 Feb 2014 at 22:09

Thanks for the advice, have you any idea if 99.9% would be safe enough or would 70% be a safer bet?

Cheers.

lord filbuster · 13 Feb 2014 at 22:44

Whatever you can get will be fine. I've used 99% on an old sigma lens to get some weird gunk off of it and it didn't do any harm. I think the only plastic that IPA damages is perspex, and I don't think there will be any of that on a lens.
It will remove ink, paint or stickers if there is text on the lens, so watch out for that.

Gogl · 13 Feb 2014 at 23:06

Ok, I'll get some in and give it a go, thanks very much.

Gogl · 25 Mar 2014 at 07:06

I just thought I'd bump this up to say that I got some 99.9% Isopropyl alcohol and used some cotton buds to clean it up and it worked perfectly, thanks

I didn't have the patience to get it looking immaculate but the aperture lock now moves freely and the aperture ring seemed to operate perfectly well, so it seems it was just glued in place because whoever didn't want to adjust it in that manner. Seems like rather an extreme option, but there you go.