Restoration of Agfa Karat 6.3
Features
The Agfa Karat 6.3 is a folding camera from the 1930s with an Art Deco geometric facade. It uses 35mm film contained in a 'Rapid' cartridge.
Being over 80 years old, it is almost inevitable that some refurbishing needs doing. The weakest points are:-
- Dust inside the lenses and viewfinders
- Dirt inside the film winding mechanism
- Unreliable Sticky shutter
I always advise to take pictures at each stage of dis-mantling to aid a proper rebuild.
Cleaning the Film Winding Mechanism
Get together some simple tools. You will need a small screwdriver, lots of cotton buds, some lens cleaner, some lighter fuel and some watch oil.
Unscrew the knob from the shutter release. Remove the film winding knob.Unscrew the screws holding the strap lugs. Lift off the top of the camera. Be careful because the viewfinder assembly might drop out with the chance of damaging the viewfinder glass.
You will now see the winding mechanism, the frame counting system and the double exposure prevention mechanism. It is important to note the position of the spring around the winding shaft as this will have to be put in this position before the top is replaced. It fits into a slot cut in the top plate. With the camera facing you, the spring must point to the 9 o'clock position.
Wipe away the grime from the mechanism. Use lighter fuel on a cotton bud to cut through the worst areas. Do this in a well ventilated space. If required, dissemble the mechanism further to get at the difficult areas.
You can check the operation by putting the wind knob back on. However, watch out because the spring on the winding shaft will move and block the mechanism. Move the spring out of the way to continue.
Before putting the camera top back on, remove the viewfinder assembly and clean the glass.
Lightly lubricate the pivots and cogs and replace the top, remembering to put the winder spring in the 9 o'clock position.
Remove the bottom of the camera, clean and lightly lubricate the mechanism.
Shutter mechanism and internal lenses
Shutter Mechanism
Undo the two small screws of the lens bezel and remove it. Remove the brass spring and the focus ring. Remove the screws holding the faceplate and remove the faceplate.
Undo the three screws holding the shutter cover in place. Do not touch the brass screw because this is used to set the focus.
You will now see the shutter mechanism. The speed of the shutter is controlled by an inertia wheel(A) driven by a rachet. Check the shutter mechanism at different speed and confirm that the rachet moves further for the lower speeds.
Gently clean the mechanism with cotton buds, using lighter fuel if necessary until the system works OK. You may have to gently move the shutter blades by using a small screwdriver to push and pull the shutter blade actuator(B). This will enable you to shift the blades out of the way to clean behind the blades. Be aware that when lighter fuel is applied, the action of the shutter mechanism will at first get worse, so gentle persuasion may be needed to get it moving. Don't Panic. As you wipe away the excess lighter fuel and it evaporates, it should start to work properly again.
By irrigating the mechanism with lighter fuel and cleaning away the debris, you should be able to revitalise the mechanism. This is not a fast process and you will need some patience. Do this in a well ventilated room. When the lighter fuel has completely evaporated, you might like to re-oil the pivots using an extremely small amount of watch oil. Use a special precision oiler pin for the job. Don't go anywhere near the shutter blades or the shutter blade actuator. These run dry.
Internal Lenses
Before re-assembly, clean the internal lenses with lens cleaner and a lens cloth. Access to the rear lens can be acheived by putting the camera in 'B' mode and accessing the lens throught the shutter.
Re-Assembly
Replace the shutter mechanism cover. Replace the faceplate ensuring that the lens cover tab fits into it's actuating slot. Replace the focus ring ensuring the tab engages with the slot of the actuator below the faceplate. Locate the brass spring washer on to the face and then refit the lens bezel ensuring the hole in it engages with the aperture driver tab.
Job Done
Was my restoration successful?
The restoration was a qualified success. The film winding mechanism was now smooth. The viewfinder and lenses were clean and clear. The shutter mechanism worked reliably. However, the shutter speeds were faster that the nominal values shown on the faceplate. About 1 stop faster. I still haven't discovered a way of slowing it down.
To be honest, this works as an advantage when the camera is used with modern film. I use the new speeds when setting exposure.
Shutter speeds
| Nominal Speed | Measured Speed |
|---|---|
| 1/25 | 1/64 |
| 1/50 | 1/125 |
| 1/100 | 1/174 |
Find out more about this camera here:- /cameras/agfa/karat/