XeKote over time tends to turn prints green, even if only applied on the edges of the film or just the projector. It isn't immediate and takes some time to show up, but it always seems to happen. It is probably a moot point now anyway, as I've heard it is being discontinued (but, that's not confirmed).

Brad, you sent me a message one time that XeKote was eating the base side and that was contributing to shredding. I asked that because the tech said NOT to XeKote between every show.

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I also fill in occasionally at a theater with a XeKote happy operator and the prints are very "nasty", to be nice. Even the platter rollers have gooey, fuzzy XeKote residue all over them. That operator sprays the XeKote across the film.

Without Xe-Kote (on the ones that DON'T use FG) the proj. doesn't seem to run right sometimes. We've never NOTICED a problem with it eating or discoloring prints but A) We nover thought to look. B) We're pretty stingy with it... We only use a Q-tip and put it ONLY on the film-bearing surfaces. (Gate Bands, Studio Guides and Int. Shoes)

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If the protective top coating is scratched or abraded, oils and solvents can penetrate into the emulsion and may leach out some of the dye, or make it soluble enough to "migrate". Excessive radiant energy can aggravate this type of damage.

A classic case of this problem occured many years ago on color prints being used in southeast Asia. Projectionists routinely used oil to lubricate prints, and the dirty conditions in some of the theatres (sometimes just a projector on the back of a truck) caused dirt to be trapped on the oily film surface, abrading the film. The prints developed green-colored spots, where the oil had penetrated through the abraded protective layer and leached out the magenta dye. Oil wiped off the surface of the film was colored pink, from the magenta dye it leached out of the film.

Care should be used in choosing any material used to clean or lubricate film. Some of the "time tested" film cleaners and lubricants are no longer available, because their forumulas contained solvents (e.g., Freon or 1,1,1-trichloroethane) that are believed to harm the ozone layer. Other "film-safe" solvents have health or flammability concerns.

There are many proprietary film cleaners and film treatments on the market. Although Kodak cannot test all of them, it has published many technical papers on the subject of film cleaning and lubrication. One paper that evaluated many of the chemicals that might be considered for film cleaning and lubrication is "Practical Film Cleaning for Safety and Effectiveness" by D.W. Fassett, F.J. Kolb, and E.M. Weigel, published in the September 1958 SMPTE Journal. Another is "Lubrication of 35-mm Release Prints for Extended Projection Life" by Edward Mino and Rodney S. Perry, in the October 1983 SMPTE Journal.

Film manufacturers strive to make prints more "robust" and resistant to all forms of damage. Generally, a small amount of oil that accidently gets on a print doesn't cause a problem with the dyes. But a sticky oily surface may hold dirt particles or cause the film to stick together. Oil blotches on the film surface may also be visible on the screen as "mottle".

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John Pytlak, Senior Technical Specialist
Worldwide Technical Services, Professional Motion Imaging
Research Labs, Building 69, Room 7419
Eastman Kodak Company
Rochester, NY 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243

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WD-40 has a proprietary formula, but it is likely some sort of lubricant (e.g., mineral oil) dissolved in solvent. The solvent(s) in WD-40 provide the cleaning action, and a thin coating of oil is left behind. The oil provides some protection against rust.

Any similar solvent or degreaser could be used for cleaning the surfaces of a projector, as long as care is used to not get the solvent into bearings, where it could leach out the lubricant. But bare metal surfaces would not be protected against oxidation (rust or corrosion). If you find that rust is a persistent problem, be sure to keep the relative humidity less than about 60 percent.

Isopropyl alcohol is often used as a cleaning solvent. In pure form, it contains little water, so it shouldn't be causing rust. Many off-the-shelf "rubbing alcohol" formulas contain isopropyl alcohol in mixture with water, so this may be the source of the rust.

Pure isopropyl alcohol may be used to clean short areas of film (e.g, removing an oily fingerprint). But if there is water in the alcohol, it will be absorbed by the gelatin emulsion and soften it. Remember, isopropyl alcohol is very flammable. Never use other alcohols (e.g., methyl alcohol) on film.

WD-40 should NOT be used as a film cleaner or lubricant, as the oil it contains may leach out the oil-soluble color dyes in the film, or cause them to migrate. Any oil on the film may be visible as non-uniformity or "mottle", and its stickiness may hold dirt particles or cause the film to be sticky or wind unevenly. Too much lubricant may make the film roll loose and slippery.

I should add that a thin film of oil on optical components is NOT useful, so keep the WD-40 away from any optics, including the lens and sound reader optics.

Please forgive me, but I do not know what Xecote is. My company doesn't order it. What is it?

Why lubricate a print?

Have you had prints that shed so much that after one show you are scooping out shovels full of white dust? Theres the reason.

Aaron