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       CLEANING TECHNIQUES
                     for shutters and camera mechanisms  to list of articles
©Infotech 2004

Cleaning and lubrication may be the most common of all repairs—especially in older cameras and antiques. Fortunately, you rarely need parts with antique cameras. And if you do need a part? If you can’t make the part, you may have to obtain another shutter or camera. Favorite Classics (see our Links page) is one possible source of parts; the web site has a forum in which you can post what you need. There’s always a chance another hobbyist or collector may be able to help.

But, as a hobbyist or collector, most of your work will probably be the standard CLA—clean, lube, and adjust. Professional camera-repair technicians often use cleaning machines—especially ultrasonic machines—to speed up the cleaning process. The ultrasonic cleaning machine allows you to clean a shutter or other mechanism with very little disassembly; it may only be necessary to remove the cover plates of a blade-type shutter. Not having to disassemble the mechanism makes the cleaning job fast. But there’s a drawback—you may not be able to reach all the lubrication points.

If you’re a hobbyist, speed probably isn’t your concern. So how far should you disassemble a mechanism? The answer depends on your own skill level. For example, with a blade-type shutter you can do the best cleaning job by removing the shutter blades. But if you’re a beginner, you may not want to take the chance that you won’t be able to reassemble the mechanism. You may then prefer to clean the shutter without removing the shutter blades.

The same is true for diaphragm leaves—only more so. The iris diaphragm is more difficult to reassemble than the shutter blades. Even experienced technicians usually prefer to leave the diaphragm intact.

CLUES TO DIRTY SHUTTERS
If you have a shutter-speed tester, you can determine the shutter’s condition by checking the fastest shutter speed—both in blade-type shutters and in focal-plane shutters. If the shutter is dirty, the fastest shutter speed is too slow. A dirty focal-plane shutter normally also exhibits side-to-side variation—the exposure at one end of the film aperture checks faster or slower than the exposure at the other end.

You may not need a shutter-speed tester to check for side-to-side variation. Open the camera back and look through the back of the aperture. Operate the shutter at the fastest shutter speed—compare the light flash at one end of the aperture to the light flash at the other end. With side-to-side variation, the light flash appears brighter at one end of the film aperture. You may even find that there’s no exposure at the closing end of the aperture—no flash of light. That means the second curtain is catching up with the first curtain. Suspect dirty curtain rollers and bearings. Another possibility—fatigue in the spring that drives the second curtain (it may be necessary to add tension after you clean and lubricate the bearings).

With a blade-type shutter, you can’t visually detect an exposure error at the fastest shutter speed. But you can detect a problem at the slowest shutter speed. The shutter may struggle to operate. Or the shutter may hang open. If the shutter operates at the fastest shutter speed—but struggles or hangs open at the slowest shutter speed—suspect dirt in the speed-control mechanism. The slow-speed governor or the air cylinder is dirty.

The same symptom appears in a focal-plane shutter at the slowest shutter speed. The first curtain fires across the film aperture. But the second curtain struggles to enter the film aperture. Once the second curtain gets past the slow-speed governor, it too fires across the film aperture. Or, if the slow-speed governor is very dirty, the shutter may hang open—the second curtain can’t push its way through the slow-speed governor.

A dirty self-timer exhibits a similar problem. When you release the self-timer, you can hear the mechanism struggle to run through the gears. Or the self-timer may not be able to run at all. And the shutter doesn’t release.

In many situations, however, a sticky slow-speed governor or self-timer may simply need exercise. A mechanical governor may hang up if it has been allowed to sit for a long period of time. You may then find that you can restore proper operation by simply operating the shutter several times. Keep your classics and antiques in good operating condition by giving them regular exercise—especially at the slow shutter-speed settings.

WHERE DOES THE OIL COME FROM?
With blade-type shutters, you'll frequently find that there's oil on the shutter blades. The oil causes the shutter blades to stick together. Iris diaphragms in shutters and lenses may exhibit the same problem. With a lens used on an SLR, the diaphragm leaves normally stay at a small aperture; they don't reopen to the largest aperture after the exposure. But factories don't lubricate blade-type shutters and lenses with oil. So where does the oil come from?

Quite often the oil comes from the grease lubrication. Heat may cause the grease to break down. The oil migrates out of the grease and settles on the hottest spot it can find—the thin metal shutter blades and diaphragm leaves. There's another source with the older shutters. National Camera once conducted an experiment to find the source of the oil. By heating the shutters, the school found that oil oozed from the metal shutter housings. Apparently oil that was used in manufacturing the shutters remained in the pores of the metal.

The moral? Heat is an enemy of cameras. People often put their cameras in glove compartments or car trunks. The heat causes lubrications to break down and batteries to fail. It can even cause some older shutters to "sweat" oil.

CLEANING MACHINES AND CLEANING SOLUTIONS
A cleaning machine—whether conventional or ultrasonic—cleans by one method: agitation within a cleaning solution. You can do the same thing without a cleaning machine. Hand cleaning takes longer and requires more disassembly. But the results are just as good.

Conventional cleaning machines, like the one shown at the left, spin a basket containing the parts within a commercial cleaning solution. The action agitates the parts and swirls the dirt away from the mechanism. The conventional cleaning machine normally has three jars for the solutions—one for the cleaning solution and two for rinses. The first rinse neutralizes most of the cleaning solution. The second rinse stays relatively clean and neutralizes any remaining cleaning solution. If you're using commercial watch-cleaning and watch-rinsing solutions, leave the mechanism in each jar for around five minutes. 

An ultrasonic cleaning machine, probably the preference of most technicians, sends ultrasonic waves through the solution (see the illustration at the top of this page). The high-frequency agitation cleans the parts. The ultrasonic cleaning machine isn’t cheap. However, it does an excellent job of cleaning—even with minimum disassembly. Use the special ultrasonic cleaning solutions with the ultrasonic cleaning machine. A cleaning solution that isn’t designed for ultrasonic machines will break down from the ultrasonic vibrations.

Just place the parts to be cleaned in the tank of the ultrasonic cleaning machine. If you’re cleaning small parts, you may prefer to place the parts in a wire-mesh basket designed for the task. Then place the basket in the tank. The basket normally has a handle so you can retrieve the parts without dipping your hand in the solution.

Or hold the part you're cleaning in tweezers or needle-nose pliers. Then, while the ultrasonic cleaning machine is running, swish the part in the solution. Remove the part as soon as it's clean—don't walk off and leave the part in the ultrasonic cleaning machine while the machine is running. If you leave a camera mechanism or part in the cleaning machine too long, the ultrasonic vibrations will remove lubrication that the factory has impregnated in the metal. Factories often tumble certain parts in dry moly during manufacture; that lubrication should remain in the metal. Given enough time, the ultrasonic vibrations can even remove the plating from brass parts. Generally it takes less than a minute to clean the part—even to remove caked-on grease. Do some experimenting to find the ideal time with your machine and cleaning solution.

When you turn off the machine, the dirt can resettle on the mechanism you’re cleaning. Again, swishing the mechanism in the cleaning solution should prevent a problem—the dirt then settles at the bottom of the tank. An ideal cleaning machine combines the features of the conventional and ultrasonic machines—a basket swirls in the solution for mechanical agitation, while ultrasonic vibrations pass through the solution for the thorough cleaning. There is such a machine. But you can simulate the effects without going to such an expense.

An ultrasonic cleaning machine allows you to clean a complete shutter after removing just the cover plates. The ultrasonic vibrations get in every nook and cranny—that’s the advantage of the ultrasonic cleaning machine. If you’re cleaning a blade-type shutter without disassembly, you'll normally get the best results if you first close the diaphragm to the smallest f/stop and open the shutter blades.

Caution: With antique shutters, check the type of shutter blades before you immerse the shutter. Some of the old shutters use rubberized, magnesium, or fiber shutter blades. Usually the rubberized shutter blades are quite thick compared to the steel shutter blades; the magnesium shutter blades are normally more flexible and a little thicker than the steel shutter blades. The rubberized, magnesium, and fiber shutter blades can’t tolerate the cleaning solution—the cleaning solution may discolor or even deform the shutter blades. Here a complete disassembly may be necessary. You can then clean the shutter blades by wiping them with a Kimwipe™ tissue or dry cloth. Be especially careful when working with the fragile magnesium blades—the blades break easily. Our tutorials on blade-type shutters warn you if there's a problem in cleaning the shutter blades.

The ultrasonic cleaning machine isn’t quite so helpful when you’re cleaning a focal-plane shutter. You don’t want to insert the entire camera into the tank—especially one with cloth curtains. As we’ll cover in this article, there are other ways to clean a focal-plane shutter. But you may still want to ultrasonically clean certain mechanisms that you remove from the camera—for example, the slow-speed governor, the self-timer, and the wind mechanism..

Drying presents another problem—especially if you’ve cleaned the mechanism without disassembly. It’s much easier to dry individual parts than it is to dry a complete unit—especially diaphragm leaves and shutter blades. A conventional cleaning machine for watches and clocks swirls a basket of parts within a heated chamber; you can see the black drying chamber in the picture of the conventional cleaning machine (above left). But don't use heat to dry the rubberized shutter blades; the rubberized blades may melt. An ultrasonic cleaning machine typically provides no way to dry the parts.

Professional technicians usually dry the parts with compressed air. But it's difficult for a hobbyist to justify the expense of an air compressor. Still there are other ways to blow-dry mechanisms. You can use the canned air; it’s not ideal for optics (the propellant may squirt out, leaving a residue on the lens), but it's fine for camera mechanisms. Or you can blow-dry the parts with a hand blower—the illustration at the left shows a hand blower designed for watch repair. Drying the parts with a hand blower takes a little more time and effort. But the results are just as good.

If you want a strong blast of clean air at a low cost, check out the air pumps designed for filling air mattresses. The illustration at the right shows a foot pump from Sevylor®, a manufacturer of inflatable products. The foot pump leaves both of your hands free for holding the nozzle and the mechanism you're drying. The foot pumps are available from sporting-goods stores or from Fargo Enterprises. For parts that you've removed, the best drying technique may be using an absorbent, lint-free tissue such as a Kimwipe™.

Some parts can air dry. The cleaning solution may leave a slight residue on air-dried parts. But, on most parts, the residue presents no problem. The shutter blades and diaphragm leaves are exceptions. Here the residue remains visible, giving the blades a splotchy appearance. If you’ve cleaned a shutter in an ultrasonic cleaning machine—and the shutter blades now have streaks or splotches—chances are the blades haven't dried sufficiently.

You can remove the splotches by reapplying just a touch of the cleaning solution; then, again blow dry the blades. A better way is to remove the splotches with Eclipse™, a methanol product designed for cleaning lenses. Since the methanol evaporates almost instantly, it leaves no splotches or residue. Wipe off splotches by first moistening a cotton swab or lens tissue with a couple of drops of Eclipse™. Then wipe off just the splotch (you don't have to clean the entire shutter blade or diaphragm leaf with the Eclipse™). For more information about Eclipse™, see our article, Cleaning Optics.

HAND CLEANING PARTS
If you have plenty of time, hand cleaning may still be the ideal method. But a proper cleaning does require major disassembly. Here’s an advantage to a thorough disassembly: you can reach all the lubrication points. Lubricate the parts as you reassemble the shutter.

Both denatured alcohol and isopropyl alcohol make good cleaning solutions. They are readily available from a pharmacy or hardware store. Isopropyl alcohol is the main ingredient of rubbing alcohol. However, rubbing alcohol may contain oils to make it easier on the skin. A pharmacy normally carries 70% or 90% isopropyl alcohol intended for first-aid purposes—it’s  inexpensive and doesn't contain oil. If you want a higher percentage of isopropyl alcohol (laboratory grade), the price goes up.

Hold the part you’re cleaning with tweezers or pliers. Then swish the part in a container of the alcohol. Or let the part soak for awhile before you swish it. If you have a container with a tight lid, you can simulate the agitation of a conventional cleaning machine—put the parts in the solution and then swish the entire container. Dry the part with a Kimwipe™ or a hand blower. If the part has caked-on grease, you may have to do some scrubbing. A toothbrush makes a good parts scrubber.

The hand-cleaning method works especially well for steel shutter blades. Hold a shutter blade in your tweezers and swish it in the solution. Then dry the shutter blade with a Kimwipe™ or similar absorbent, lint-free tissue. You now have a clean shutter blade with no streaks or splotches from the alcohol.

CLEANING FOCAL-PLANE SHUTTERS
Cleaning focal-plane shutters presents a new problem. You don’t normally want to completely disassemble a focal-plane shutter. If you do, you can lose critical timing between the two curtains. Plus it’s nearly impossible to accurately reset the curtain tensions unless you have a shutter-speed tester.

Most technicians flush-clean the curtain bearings. Tension rollers, or "take-up" rollers, such as those shown at the right, spin around a center rod. Using an artists’ brush, apply the cleaning solution to the area between the center rod and the roller. Move the curtain roller up and down and back and forth a few times to work in the solution. Then use compressed air, the foot pump shown earlier, or your hand blower to blow out the solution. Repeat the procedure a couple of times to assure that you’ve removed the dirt and the old oil lubrication. Then give the same treatment to the next roller.

What if you get the solvent on the curtains? Use your air blower to immediately blow-dry the solution. A mild cleaner such as isopropyl alcohol won't cause damage if you immediately blow it dry. A strong solvent, such as acetone, may attack the cement holding the curtains to the rollers. That's why we normally recommend using isopropyl alcohol; it's safe for most cleaning applications in cameras—even if the camera has plastic parts.

Winding rollers—the rollers at the other side of the camera—are attached to their center rods. Apply the cleaning solution between the center rods and their bearings in the camera body and mechanism plates. Again use your finger to move the rollers back and forth and up and down. Then blow out the solution.

Note: With the Pentax shutter shown at the right, the tapes of one curtain (the first curtain) attach to two small rollers. The small rollers are fastened to the center rod. A free-spinning roller fits between the two small rollers; the free-spinning roller routes the second curtain. As the second curtain moves in either direction, the free-spinning roller turns on the center rod. Here you should also flush clean the bearings of the free-spinning roller (where the center rod passes through the free-spinning roller).

For other parts of the camera, you can use the techniques we’ve already discussed. If you remove the wind mechanism as a unit, you can clean it by hand or in an ultrasonic cleaning machine. The same is true for the slow-speed governor and the self-timer mechanism.

REMOVING RUST OR CORROSION
It's common to find rust damage in the older cameras—especially in those cameras that predated the age of plastic (plastic isn't a bad thing—at least it doesn't rust).

There are commercial solutions available for removing rust. But the glass scratch brush probably provides the fastest, most reliable method. The glass scratch brush has glass bristles that literally scratch off the rust. The drawback is that the glass scratch brush leaves behind bits of the glass bristles. If possible, remove the part before scratching off the rust from that part—don't risk getting the broken bits of glass in the camera. Then thoroughly clean the part. If you can't remove the part, make sure you wash out or blow off all the residue from the scratch brush.