Sigma 400mm apo

mark fewtrell · Joined: 26 May 2015 Posts: 70 Location: herefordshire

Just been given this and the surface is sticky. Needs cleaning. What can i use? In UK so maybe lighter fluid?

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

I use ethanol-soaked paper towel to remove deteriorated rubber from Sigma lenses. a. It will be messy b. You will lose markings - it's as if they are done in watercolor. c. Be careful around distance scale window.

mark fewtrell · Joined: 26 May 2015 Posts: 70 Location: herefordshire

Thanks. Looks almost like hand grease. Same as a computer keyboard wrist rest. Test this!

Lloydy · Expire: 2022-01-01

I've had some success with 'Sticky Stuff Remover' - which contains among other things '30% aliphatic hydrocarbons' (which almost certainly kills baby seals and destroys the ozone layer) but is something I bought in a local discount store and is excellent for removing sticky label residue, tar, grease and even chewing gum.

http://www.lakeland.co.uk/8976/Sticky-Stuff-Remover?gclid=COfDnfOS7soCFckaGwodr1gBSw&src=gfeed&s_kwcid=AL!49!3!97989372629!!!g!42447399660!&ef_id=VVRw-AAABCuUR38U:20160210213313:s

I does leave a bit of residue on some surfaces, but it does dissolve the sticky stuff. If there's a residue I clean that off with lighter fuel.

I would definitely test on a tiny area first, but I have never used it on anything where it has affected the surface.

Another method of curing a sticky surface that I have tried once with success was on an old Canon EOS film camera that was so sticky that it would support its own weight just stuck to my fingers. The sticky stuff remover wouldn't touch it, neither would any solvent I tried. And this camera was basically worthless so I was experimenting.
Then I read that a lot of the 'rubber' used on camera and lens grips is actually a plastic, and the stickyness is due to the chemical components separating with age, and worse - the solid base of the plastic was the component that was being lost and the gooey mess was the binder. So I tried to replace the 'solid' part, and I chose chalk to try this crazy idea.
I made chalk dust and worked it into the grip with my fingers, just rubbed it in. I did it for about 4 or 5 times over a few days and it worked. The grip felt just like new. I then rubbed some black shoe polish on it and it looked new.
I gave the camera to a guy who has had it for over a year and it's still good, but obviously different materials from different manufacturers might respond very differently. i was messing with a camera that would have been binned otherwise. Wink

mark fewtrell · Joined: 26 May 2015 Posts: 70 Location: herefordshire

Maybe I could use different clour chalks as camo! Old manual lens. 400mm is useful. Canon fd mount. Also seems to have a slight haze of oil I think which is common. Could still have some fun in it.
Thanks.

luisalegria · Expire: 2018-01-18

Other brand to try is Good Gone

jamaeolus · Expire: 2015-08-20

Goo Gone, I think you mean, another one is Goof Off.

mark fewtrell · Joined: 26 May 2015 Posts: 70 Location: herefordshire

Evostick do one. What about nail varnish remover.

Rigel · Joined: 26 Nov 2015 Posts: 121 Location: Belgium

Lloydy · Expire: 2022-01-01

Rigel · Joined: 26 Nov 2015 Posts: 121 Location: Belgium

depends what one defines as "solvent" ... Solvents range from aliphatic compounds (pentane being the first liquid compound in the row) up to water. Depending on their polarity they are able to dissolve a specific sort of compounds but the extremes do not mix nor dissolve. That's why I wondered what the other 70% was as it has to be soluble un the "aliphatic" part. The most powerful glue removers are the ketones and the ethers and these do not mix well with the CHn-anes. oh well ...

Lloydy · Expire: 2022-01-01

Now I am officially confused Laugh 1

As a last resort I go to MEK, but that has a tendency to dissolve just about anything.

Rigel · Joined: 26 Nov 2015 Posts: 121 Location: Belgium

LOL .. yes MEK = methyl-ethyl-ketone .. the brother of di-methyl-ketone=acetone .. as you experience these dissolve almost anything just like di-ethyl-ether the classic medicinal ether. Or any mix of these. Another top-hit is ethyl-acetate (also in some nail-polish removers). They're no good friends with anything "plastic" Laugh 1

mark fewtrell · Joined: 26 May 2015 Posts: 70 Location: herefordshire

I would like to say i'm wiser. I would like to. Are we saying on plastic no acetone? This is a old 400mm sigma plastic i think. To clean it all i can see it gunk off or some such.

Rigel · Joined: 26 Nov 2015 Posts: 121 Location: Belgium

If it is plastic, then I would try the two extremes aka zippo fluid to remove "greasy" stuff and methanol to clean (apparently that is not "methylated spirits which seems to be ethanol denaturated ..?)
I've had some pretty good results with methanol (the stuff used in alcohol burners, blue flame)