What is "naphta", "lighter fluid" used for lens/camera cleaning

Not being a native english speaker, I always wonder on what people mean when

they say they are using "naphta" or "lighter fluid" for cleaning lenses and also

camera inerts. I first thought it is naphtalene, but given its properties I

highly doubt it. Wikipedia gives a number of chemicals which could relate to

naphta including ethanol, methanol, benzene, ether (that's not exactly easily

available for household use). Could somebody enlighten me, which -as a pure

substance, not a mixture- is usually refered to when talking about "naphta"?

(chemical names, please, not brand names).

 

Thanks.

Naphtha is a solvent that has typically been used in the U.S. as a dry-cleaning fluid:

 

 

http://en.wikipedia.org/wiki/Naphtha

 

 

Naphtha is found in cleaning products like Goof-Off:

 

 

http://www.valsparglobal.com/val/resident/goof-off.jsp

 

 

I could see using naphtha to de-grease metal parts or to remove crusty gunk from metal surfaces. I certainly wouldn't use such a solvent to clean optical glass.

Naphtha is a generic term for what is usually a mixture of hydrocarbon components. Typically these are the -anes; C5H12, C6H14, etc... There is no "pure" naphtha.<P>"Benz<b>e</b>ne" is not naphtha, however I have heard it called "benz<b>i</b>ne.

To be clear, I wouldn't use any degreasing solvent, including lighter fluid, on optical glass.

Naphtha isn't a pure compound. It's similar to gasoline in that it's a mizture of light hydrocarbons.

 

It should dissolve non-polar organic compounds (e.g. grease) quite well.

 

I wouldn't use it on a lens unless the lens was covered on something like tar!

 

See http://www.bobatkins.com/photography/tutorials/lens_filter_cleaning.html for more info on cleaning clenses

 

Methanol or Ethanol is a better choice of solvent. Acetone dissolves stubborn organics well, but also dissolves paint and many plastics, so should be used with care.

 

I presume people use stuff like lighter fluid because it's easy to find, not because it's a particularly good choice.

In the US, when people say "lighter fluid" in relation to camera repair, they usually refer to Ronsonol brand. Its Material Safety Data Sheet, which includes its exact chemical composition, can be found here:

 

http://www.cooperbooth.com/datasheets/160606.pdf

In response to Bob's comments, yes, you are correct in that methanol or ethanol are better choices for lens/filter cleaning. But lighter fluid is usually used for cleaning oily shutter or aperture blades. It also will not harm plastics and so is a safer choice where plastics are involved.

when I bought a Miranda f/1.8 lens on the bay it had a

sticky diaphragm.

the design was such that the front and rear lens groups could be set aside and only metal parts remained.

 

I swished it in 120 proof grain alcohol - ethanol.

 

this was not too effective, it freed up the diaphragm. but after a few monutes it got sticky again.

i think naptha/ lighter fluid or a similar solvent would work better.

 

In the olden days, we had all kinds of solvents at work.

acetone will destroy common parts as it is a very strong solvent.

 

Carbot tetrachloride ( carbona) is a health hazard but may be safer on some plastics. but not for people. back then the use of plastics was less common.

 

the Freon TF is safer solvent and that is what i eventuallu used with no harm to the lens body or diaphragm ( no glass)

 

it was the common Miller-Stevenson brand inb a white can and green lettering. used at electronics planmts.

 

2 years later I repeated the same thing. no harm to the diaphragm assembly.

 

now i have 2 more lenses requiring the same thing.

 

BTW be careful my f/1.4 lens is a different construction,

there are many small lenses and they come out in small pieces not 2 large groups

I don't know what's available where you are, but when I needed naptha to unstick a leaf shutter, I went to the paint supplies aisle at a local hardware store and found it sold in 1-quart steel cans labeled specifically as "naptha". I don't think it's exactly the same as paint thinner though, because they had separate cans of that (although they smell and look pretty much identical as far as I can tell, not that that means anything).

As Donnie said, lighter fluid would be ideal for cleaning the greasy internal parts of lenses. It's not really a good choice for optics unless you have grease smeared on them.

 

If you can't find ethanol or methanol, isopropanol (isopropyl alcohol) is easier to find and is also OK for cleaning optics.

Bob Atkins is spot on. He is a chemist (as am I). Naphtha (e.g., lighter fluid) is an unspecified mixture of hydrocarbons, described by its boiling point range (q.v., kerosene, gasoline, fuel oil, etc). Any solvent, unless specially purified, tends to leave a residue on evaporation which you would have to remove by some other means. This does not matter when you are lighting cigarettes, I suppose. What's one more contaminant? Naptha, or mineral spirits (safer) would be a good choice for removing oil from isolated metal components, like the focusing threads, diaphram or shutter mechanisms. I would not use it on optics.

 

Methanol and ethanol and isopropanol are available as relatively pure substances, though not necessarily with low solids content. Methanol, marketed as Eclipse Fluid, is spectroscopic grade material with no significant residue on evaporation. No solvent is safe for all materials. Being highly polar, methanol is not aggressive toward most plastics and is a reasonably good solvent for light mineral and organic deposits on lenses when used as directed. Distilled water (to dampen a lens tissue) would be a good choice for salt spray or saliva.

 

Chlorinated hydrocarbons tend to attack thermoplastics, and are toxic to breath or use in contact with skin. Freon analogs can be used, in gaseous state, as directed (e.g., canned air). Acetone is also much too agressive, and nearly always leaves a white film on evaporation (possibly condensation by-products).

 

Lenses should be cleaned only as a last resort. If possible, use a blower (never by mouth) or a dry lens brush before applying any solvents.

With many late 40s and early 50s lenses, some kind of heavy grease was apparently used to make the lens focus rings move smoothly etc. In any case, over time whatever was in there has stiffened, and the use of a solvent like naphtha can help in loosening up this gunk without having to do a dissassembly. As several have pointed out, however, any petroleum solvent needs to be used with caution, and should never be allowed to get close to cements used in the glass portions of the lens. A little solvent on a rag, might help to get something like a tar spot off a piece of glass, but it can dissolve the cements holding lens elements in place if you're not careful. Used carefully, these solvents are the liquid equivalent of a blast of air to knock dirt out of a mechanism.

Thanks a lot everybody; my question is (better than) sufficiently answered. I don't have any problems of access to highly pure solvents incl. spectroscopic grades, and that was the origin of my question: I don't like unknown, secret mixtures used in brand named stuff not specifically made for my purposes. They might contain things which are of no problem for the intended purpose (paint stripping) but might leave residues upon lens cleaning. Ronsonal might be great, but I haven't seen it in shops around here.

 

Seems I will follow my old habits using H2O, MeOH, EtOH on lens surfaces, and acetone, benzene, CCl4 for cleaning out old grease and oil.

 

Thanks again.

Naphtha (Benzine) is a good solvent for most oils and greases. As mentioned it is an inexpensive mixture of various hydrocarbons with boiling points ranging from 30 to 60 degrees Celsius. You don't want to work with it in enclosed areas unless you are searching for a good high before everything blows up around you. I have often used it to clean diffraction gratings and other optical components, particularly those used in vacuum chambers. One way is to immerse the item completely under the solvent and lightly brush the surface to be cleaned. Obviously you don't want to do this with a complete assembly like a mounted objective (lens system). There are usually better ways to clean most optics than using naphtha.

On advice of an old timer I used lighter fluid to clean an old 135mm Optar from my Super Speed Graphic. I wouldn't do it again.

As someone else noted above, don't confuse Benzine with Benzene. Benzene is an aromatic hydrocarbon and is a known cancer causing agent as well as being generally nasty stuff that can make you sick in all sorts of ways. Benzine is a mixture of light alkane hydrocarbons (similar to gasoline). Not exactly good for you, but certainly not as nasty as Benzene.

Lighter fluid is what you put into a cigarette light (Zippo, Ronson, etc.) to make it work. Perhaps with all these modern disposable lighters, many people have never seen a lighter that used a replaceable flint and lighter fluid. I would imagine that all lighter fluids are the same.

One of these days, I'll shoot a sample of Ronsonol into the GC/Mass Spec to see the exact molecular weights as well as number of isomers present.

 

In the meantime, just know that it's a mixture of lightweight, volatile hydrocarbons. I have not found it to leave any residue on evaporating, but this isn't something for which I've specifically tested.

 

I personally prefer to use just straight hexane for camera/lens cleaning, however not everyone has access to this.

Yikes !

Ben H. wrote: "One of these days, I'll shoot a sample of Ronsonol into the GC/Mass Spec"

 

Great idea; I would like to see the results just out of curiosity. It would show whether my fears that manufacturers either put any own stuff into it or leave unwanted impurities in, are justified or not. I am aware that MS will not give too much information on the quantitative ratio of the components, but will be very accurate on what different stuff is actually in it. Hope you can present a figure?

Konrad,

On the machine to which I have access, the trace displays both the relative intensity of the signal, from which the ratios of individual components can be calculated, as well as the mass spectrum for each peak on the trace.

 

This machine also has a flame ionization detector, which of course does give full print outs of the relative abundance of every different compound and isomer. It currently has a totally different column than the mass spec(30 meters and polar rather than 10 meters and non-polar), so the results don't exactly match up.

If you are searching for a supplier for this solvent, try Harshaw, Sargent or other national chemical suppliers. You may also find the solvent also listed as Petroleum Ether.