PART TWO
TOOLS & MATERIALS
In Part One of this series, we examined useful reference books for repair students because you can never have too much information about your subject. This week we’ll cover some requisite items you’ll want to source, places to find these, followed by a look at optical bonding products.
The “dental picks” above are not medical grade. They were bought via eBay for around $20. They’re not as durable as proper dental picks, but neither are they as expensive. If you have a dentist in the family, perhaps you’ll be able to find some genuine ones? But for unhooking and attaching small springs and other fiddly tasks, these hobby ones will do the job just fine.
These drivers were acquired from various suppliers and are OK to get you started. You may find yourself upgrading to premium quality such as Wiha if you really take to repair activities longer term.
Micro-Tools
Micro-Tools are probably the best known specialist supplier of tools, materials and lubricants to the repair trade. They stock the miniature screwdrivers, tweezers and other implements for fine mechanical work available from numerous other sources. But they also list those items tailored specially to the repair of cameras and optics—Eg. Lens spanners, collet wrenches, rubber tools, lubricants, and other materials which are helpful or, in some cases, essential for certain tasks. Their range of stock is huge.
If you specialise in particular models, it’s easy to justify buying or making those special tools that save time, effort, or minimise accidental damage. Micro Tools sell these collet wrenches in a wide range of sizes. They’re tailor made for loosening tight lens groups or other round parts with minimal effort and—critically—without damaging them. As one of just a few people to regularly work on Zeiss Contaflex SLRs, I bought this wrench specifically for removing the often tight centre lens group of these quality lens shutter SLRs, without distorting and damaging their soft, brass mounts.
Edmund Optics
Edmund Optics supply specialised optical bonding agents or solvents from makers like Norland, not easily found elsewhere. Products such as Milbond adhesive are designed for cementing optical pieces—not a process for novice repairers, but it’s wise to know the materials available and why they’re used. It’s part of the big picture of repairing old cameras (which includes knowing what is out there, what you know, and, what you don’t know). One day, you may want to use them.
Not all tools can be readily purchased. Both the above began life as ordinary blade screwdrivers, but have been adapted to other purposes by slotting them with a Dremel. The longer one helps me to adjust the reflex mirror height (and, hence, viewfinder focus) of a 35mm Contaflex SLR. The shorter one is essential if you are to avoid damaging the soft brass nut that fastens the focus knob of a Rollei twin lens reflex to the end of its focus shaft, which must be loosened when focus calibration is performed.
Ebay
The big auction site has no shortage of interesting items repairers. Screwdrivers, lens spanners, hobbyist dental picks, files and many other small tools are listed, both by general tool sellers or some specialist suppliers to jewellers or horologists. It’s also the best place to find Canada Balsam at affordable, prices. Brass and steel shim stock of various thicknesses for making washers and shims with which to adjust clearances etc. may be readily obtained, too.
These lens spanners from eBay were chosen for their longer than average length. The additional reach is essential if you are an admirer of the various Rollei TLRs and need to loosen the inner lens group—I fall into this category, and selected these pairs for this reason.
Sometimes there’s simply no substitute for certain tools, to do a particular job done right. If you’re going to take on Rollei lens board parallelism—not for the faint-hearted—you’ll need to be able to measure shims with precision. A 0-25mm (or 0-1 inch) micrometer is both the best, and simplest way. For accurate sizing of parts to a lower resolution, vernier calipers are quick and reliable when correctly used.
Cleaning Solvents
Broach the topic of solvents to a group of camera repairers and you’ll get a range of suggestions. In truth, most types have advantages and disadvantages, however the most universally recommended fluid for general cleaning of mechanisms is lighter fluid. It’s certainly the one I look to in the first instance, unless there is a specific need for alternatives, such as lens cleaning, where I’d usually avoid lighter fluid (unless for instance a lens is particularly dirty and needs surface grease or other contaminants removed before “normal” cleaning).
I prefer lighter fluid for most tasks because, whilst its petroleum fractions are light, highly refined ones which flash off easily. They’re also harmless to nearly all the materials used in film cameras over the last sixty or so years. Alcohol is often mentioned, but it may potentially react badly with certain soft plastics (such as SLR focus screens). Screen manufacturers such as Katz, Maxell and Beattie do not recommend it (briefly, don’t use fluids on these at all if possible, otherwise when unavoidable distilled water will not itself harm them, though the same may or may not be said for any contact you make with them).
Acetone, whilst undoubtedly useful for certain specific applications, has a voracious appetite for painted surfaces and must be used with great discretion. Lighter fluid is a reasonably effective cleaning solvent and is very unlikely to harm anything it contacts (advertently or otherwise), when used in reasonable amounts. This is not, however a licence to drizzle it into shutters or other mechanisms—it’s of great assistance to the repairer, but is rarely ever a repair, in its own right! Invariably, less is best.
Canada Balsam
Prior to the development of synthetic lens bonding compounds, lens pieces comprising two or more pieces of ground glass were traditionally bonded with Canada Balsam—literally, resin extracted from the Balsam fir pine found in parts of Canada.
Historically used also for mounting microscope specimens onto glass slides (still sometimes the case today) Canada Balsam is very close to optical glass in its transmission of light. It also possesses a tendency to yellow or go brown decades after application which can severely affect items assembled with it. Therefore its use in the commercial manufacture of photographic optics has diminished greatly from the 1950s.
Carl Zeiss were one of the first companies, if not the first, to adopt synthetic bonding alternatives to Balsam. It’s interesting to note that, decades later, certain older Zeiss lenses assembled with early synthetics (including some Planars and Sonnars used in Rolleiflex TLRs and Contaflex SLR lenses) manifest a tendency for cemented doublets to separate because the cement may slowly relinquish its hold on the glass. Hence, the move from Canada Balsam was not without its initial problems, even if these problems didn’t always appear until decades later.
Most modern synthetic lens cements tend to be of the “UV cured” type—the cement will remain pliable to permit the precise alignment of the glass pieces to be joined, at which point the work is exposed to ultra violet light for a specified period, which rapidly cures the cement. This clearly offers time and efficiency benefits to a modern production facility. It’s easy to see why manufacturers began to implement synthetic adhesives when they became available.
Modern lens cements are now very stable when correctly applied, but they do have two potential disadvantages for the DIY repairer. Firstly, once opened, they have a relatively short shelf life which can result in wastage and additional expense. Secondly, when cured, their grip is tenacious, which can be problematic if the job needs to be re-done for any reason, which, in a home workshop without all the facilities of an optical manufacturing, it possibly might.
Canada Balsam, on the other hand, may have (very) long term stability issues, and it takes longer to cure but this last point is one I see as more of a benefit than a liability—it makes the bonding process more forgiving even if some more care may be dictated initially, in order to stabilise the optics satisfactorily until curing is complete.
I have not yet had to do any optical bonding (I’d be prepared to do so, if a particular lens that presented itself was valuable enough to warrant the effort). If so, I personally would incline towards Canada Balsam, rather than modern synthetics, because the former is easier to re-work if a piece needs to be adjusted. And with many Balsam cemented lenses from the 1930s or earlier still surviving in good, usable condition today, any long term complications arising from it over the next forty or fifty plus years are unlikely to be my concern at my age...
Canada Balsam is usually expensive, and difficult to procure in smaller quantities for home users. It’s traditionally sourced through specialist medical and lab suppliers in large volumes at high unit prices—totally impractical for DIY purposes. Fortunately, there are now some sellers who now sell it online in smaller sizes, so anyone who needs to do a little optical assembly (or mount a few microscope slides) can easily acquire it affordably. Here is link to one such listing at the time of writing.
Not all repair tools are best sourced via eBay or specialists. These medical stainless steel tweezers are, believe it or not, disposable items and are discarded after use. They’re also perfect for holding all manner of small parts like screws and springs, and ideal for finessing these in and out of nooks and crannies your fingers just can’t reach. To me they’re as indispensable as a good set of screwdrivers. Ask your family doctor or public hospital staff politely, and you might be in luck.
Connect
I'm a photographer who images on 35mm or medium format film. I enjoy using older, all manual cameras from my collection, and I'm also a self taught camera repairer who can never resist just one more German classic (according to my long-suffering wife). We live on a few acres of forest and pasture near Hobart, with our two children, four Border Collies, three cats, alpacas, goats, geese, ducks, peafowl, turkeys and chickens, and Tasmanian native fauna species like echidnas, wallabies, kookaburras, bandicoots, (and many others). You can see more of my work here or via my Facebook page. I have also recently started a blog about my adventures in film and collecting and repairing old cameras.