The Paint Process
PLEASE NOTE: DUE TO CURRENT WORKLOAD, WE CAN ACCEPT NO FURTHER REPAINT JOBS UNTIL THE 2ND QUARTER OF 2019. NORMAL SERVICING WORK UNAFFECTED.
I am often asked about the painting process of Leica cameras. The idea is quite simple but the execution is complex if one wants to end up with a professional finish. Sure, it is possible to clean up the metal and give it a 'key' to adhere to with sandpaper but this is not the way we approach the problem at cameraworks.
Most cameras we are asked to paint are chrome plated. Chromium is quite possibly the worst substrate for paint. Chrome is excellent at repelling dirt and equally good at repelling paint. Any paint job done on such a surface is guaranteed to fail and when it does, it will reveal the underlying chrome finish, not brass as one would expect on such a camera. Not only will a poor paint job be unreliable but could de-value your camera significantly and in some circumstances, applying paint in the wrong places can cause 'interference', where a moving or sliding part no longer moves freely, due to the thickness or contamination of the paint layer.
At cameraworks, your camera undergoes a multi-step process to arrive at the finished product. Due to the individual nature of each camera, everything is done by hand. This includes careful cleaning and de-greasing, dipping in various toxic chemicals that have to be very carefully monitored, precision grit blasted and hand finished before and after paint application. Here are the 15 steps:
The camera of course needs to be fully dismantled. Every single moving part (to be painted), must be dismantled down to its individual components. This is why it works out cheaper to have your camera serviced at this time. Depending on the colour scheme this also may include screws etc. Attention is paid to certain parts such as the glass/acrylic VF/RF lenses on M bodies. These have to be carefully removed prior to work. Also, Leica M3/M4 have a lens above the counter dial. Early cameras use a glass lens, later cameras use a plastic lens. In order to paint the bezel, the lens has to be very carefully removed. It is attached using a bezel setting, sometimes known in the jewellery trade as a rub-over setting. Any mistakes at this stage will ruin the lens or the setting.
Cleaning and De-greasing
This includes manual cleaning of all parts in order for the various stripping chemicals to do their job. Vapour degreasing / ultrasonic cleaning may also used at this stage which effectively removes the infill of the engravings.
Chromium is never applied directly to brass. Firstly, a flash layer of copper is applied, over which a relatively thick layer of nickel is applied. The final chrome layer is very thin. This can be removed by reverse electrolysis or acid. Both methods work and each has their advantages/disadvantages. In both cases great care must be taken to ensure only certain parts are treated this way otherwise surface damage can take place.
Nickel and Removal
After cleaning and inspection, certain parts are de-plated again using acids or reverse electrolysis. This is the stage where the potential for damage is great. Incorrect treatment can actually damage the surface of the brass so again, close attention is paid to the process at this stage.
At this point we clean and remove any traces of previously used chemicals as they may continue to etch into the parts in the future.
Hand-Finishing Before Paint
If required, each part needs to be finished by hand, using a variety of media to result in a bright shiny finish. Any marks or scratches may be visible through the paint finish so we take great care at this stage. Parts that could not go through the stripping process are also finished at this stage.
Quite often, your camera will have a number of dents and dings. Very minor marks are usually left alone (unless you tell us otherwise) but nasty dents or gashes are repaired. Generally, these are repaired using a metal working method – using metal to repair metal. The finish is superior and as the paint wears, it will result in metal being revealed rather than plastic-based filler.
Cleaning and De-greasing
This removes and dirt or grease prior to painting. After this, parts are only handled using rubber gloves, to prevent contamination.
We have a set-up deigned for grit-blasting precision items. The grade of grit is very fine. The process is designed to give the surface a final clean, mainly to remove any oxidation and provides a micro-key to enhance paint adhesion. Due to the nature of brass, the time window for painting after this process is very short.
Paint is applied using a precision airbrush in a small ventilated booth. Each part is coated sufficiently to give a good coating but not too thick as to obscure engravings which will be back-filled later.
All paints we use require to be cured at temperatures up to 140 degrees Celsius for several hours. The gloss paint we use is a special formulation to closely replicate factory enamel both in look and original formulation. It is not the commonly used 2-pack paint used in the automotive industry as we find this paint high-build and unsuitable for use on cameras. We also occasionally use firearm paint. This is a 2-pack paint but especially formulated to be low-build. In both cases, interference is minimised and unless the brass is very worn, engravings are maintained.
We infill the engravings with suitable enamel paints. On older Barnack cameras, a process of Wismut was originally used. At the time, a painted part would then be engraved and the grooves filled with a eutectic alloy containing cadmium. While we can still do this, the problem is at this stage is that the engravings are effectively filled with paint. We have developed an alternative method of filling such engravings with a silver-based material that is a very close match to the original, but without the toxicity.
Certain parts such as the top/bottom plate are often painted on the interior with either non-reflective paint or wrinkle finish.
Final Hand Finishing & Brassing
There is an optional step at this point. Some clients like us to do a final hand-finish on the camera. This includes flattening the paint and if required, brassing of the edges to specified levels. By doing this, the surface of the paint flattened and burnished in the way an original camera would, after some considerable use. The constant rubbing of skin over the paintwork would eventually produce the same result. Any brassed areas are also treated with liver of sulphur, which causes the exposed brass to quickly develop the brown patina we're all used to seeing. White infills can also be aged to make the camera look more authentic.
Your camera is carefully reassembled and tested before dispatch. I hope you can see from this list that not only is your valuable camera in good hands but that there is much attention to care and detail. We believe your freshly painted camera will be a joy to use but will have gained some value too.
Lenses go through a similar process but usually, depending on the lens, certain parts are made from aluminium. These parts go through an additional chromate conversion process which stabilises the metal. Without this, it is possible the paint will flake off.