It has become easy and relatively cheap to digitize your old photos, as the popularity of slide and film converters notably demonstrate. Like most of these nifty devices, it even comes with a cleaning brush to help you prepare your old films for clear scanning.
However, cleaning with an included brush is only suitable for a best case scenario. Old photos are often afflicted with more than mere dust particles, depending on how well you have preserved them, and how long have they been in storage. You could be dealing with fungus, mold, mildew, spilled ink and other liquids, and all kinds of residues. More likely than not, after decades of storage, humidity alone would produce conditions for organisms to multiply, even if you thought that the films were securely packaged and stored.
And even if you are only dealing with dust, when it comes to high resolution scans, you would still want to engage in a thorough cleaning, preferably chemically treating your visual legacy from the last century, in order to get the best results when it is finally digitized with a 35mm slide converter or flatbed scanner.
How to Clean 35mm Slides
The Necessary Cleaning Tools
First, don’t ever use tap water, only distilled one that you buy at the store. Tap water is full of minerals, so when it dries out or when you smear it on the film, it will definitely leave stains behind. That is, if you would want to use distilled water at all, as there are much better cleaning solutions.
Same goes for the cloth you use, anything not exclusively made for cleaning camera lenses and dioptric glasses will probably leave lint and dust particles. This includes paper towels. If you search for ‘microfiber cleaning cloth’ you will most certainly find the right product.
Additionally, you should also get a nice pair of microfiber, anti-static gloves. All the extra care in the world will not stop you from leaving greasy marks on the film if you do not envelop your fingers in proper, flexible, microfiber gloves. As was the case previously, just entering “microfiber gloves” into your online store of choice will yield many results.
A compressed air can or air blower is also a necessary tool to have; you can find it in any good computer store. If you are a PC owner, you probably own it already as it is the most effective tool to clean computer cases every six months or so.
Preparation of Your Slides
Take a closer look at your 35mm slides. In most cases, the edges of the slides will have some amount of dirt on them, which is very difficult to clean without removing the slide mounts altogether.
If you do not notice any dirt, or it is very slight, you are quite lucky and using the anti-static brush in combination with the compressed air can would probably do the trick.
Nonetheless, if you want to do a thorough cleaning job for the best possible conversions into a digital format, that would not require any repeats, here are some tips you should follow.
Best Cleaning Practices
Now that you have your microfiber cleaning cloth and gloves, you are ready to proceed to the actual cleaning process of your 35mm slides.
As already mentioned, it is always best to completely remove the film from the mount, because it is very difficult to clean out those edges. But you be the judge if it is absolutely necessary, and if the digitized results were to your satisfaction.
If you have cardboard mounts for the slides, it would be wise to switch to GEPE slide mounts, as this would eliminate the possibility of leaving cardboard fragments during the scanning process.
Additionally, as GEPE slide mounts are much sturdier, they would keep the slides flatter while scanning. For the best results, you could go with ANR glass holders, which would leave the film unmounted, with direct contact with the scanner surface, thus offering the best scan result.
Once you have everything set up, first use the compressed air can to blow over the film. This is the first step so as to not scratch the film with dust particles, even if you do it with a microfiber cloth.
Only then you use the cleaning brush, that you either got with your digital conversion bundle kit, or bought from the camera store. VisibleDust 1.0x Sensor Brush is a good option that is frequently employed to clean DSLR camera lenses, but there are cheaper, just as good options, available in any camera store.
PEC-12 Film Cleaner
Next, the most important part – choosing which cleaning liquid to use. Again, there are many film-cleansing emulsions to choose from, but PEC-12 stands out from the crowd.
PEC-12 is a waterless hybrid of organic hydrocarbon solvents, pH neutral, and contains no damaging chemicals like chlorofluorocarbons and chlorinated hydrocarbons. It dries almost instantly, causes no swelling, and leaves absolutely no residue. It’s an archive-grade film and print cleaning solution, so you will definitely get the best scanning result with this solution.
In addition to not damaging your 35mm slides in any way, even after repeated use, PEC-12 will clean all the most common stains from your film: adhesive tape residue, mildew, fungus, smoke and soot residue, finger oil, grease pencil, permanent inks, etc. Anything you can think of, PEC-12 has the best chance of removing, without incurring any damage to the film.
Keep in mind that only slight pressure is needed when applying any such solutions. You will immediately see a huge difference, and after you swab the film with the microfiber cloth, they will be in perfect condition to undergo the scanning process.
To conclude, although some of these procedures employ costlier measures, it would be wise to remember the most basic standards when it comes to cleaning 35mm slides, from which you should not deviate:
- No tap water, only distilled one, if you just don’t want to splurge on a proper cleaning solution like the PEC-12.
- No ordinary fabric, for both your hands and for the swabbing cloth. Microfiber gloves and cloth is the way to go.
- Always use an air blower on the film before touching it with anything, as dust particles tend to be abrasive.