Canonette 28 (new version) sticky shutter repair

Discussion in 'Camera Building, Repairs & Modification' started by johnalex141r, Sep 6, 2010.

  1. johnalex141r

    johnalex141r Member

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    I picked up a Canonette 28 at the local good will store; light seals were removed, but before ordering a new seal kit from Jon Goodman, I wanted to get the "sticky shutter" repaired.

    I removed the rear element and noticed that there was foam and foam residue back there. See the attached picture; you can see the lens there. Removing this lens, and "hitting" the shutter with some cleaner (end of bamboo stick) eventually got the shutter working on all manual apertures with a satisfying "clunk".

    Now to get the light seals, and, then we have another working camera!

    JohnS.
     

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  2. Andrew K

    Andrew K Subscriber

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    from memory there was a ring of light seal material around the rear of the lens opening on a new type canonet 28..

    to clean it fully you do need to remove the shutter unit...but I must admit I've never heard of anyone cleaning the residue off the way you have - who knows how long it wil work - hopefully for a while :smile:
     
  3. johnalex141r

    johnalex141r Member

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    Hi Andrew;

    Could be that the shutter was "sticky" because of something other than a bit of decayed foam. Anyway, when removing the back lens element, bits of chunky foam stayed behind; these were carefully picked up by sticky tape on the end of a bamboo stick.

    Q) Do you think the shutter stickyness could be because of the foam, or something else?

    Q) Do you think I should replace this foam, or just hope that there are no light leaks coming in here?

    Yes, I hope that this little guy keeps working for a while.

    Thanks - JohnS.
     
  4. AgX

    AgX Member

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    This foam makes no sense as a light seal at that position.
     
  5. Andrew K

    Andrew K Subscriber

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    Hi John

    I know it makes little sense why there is foam on the back of the shutter, but over the years repairing cameras I've seen many things that haven't made sense...

    I've only repaired a couple of these cameras, and I don't think I ever needed to replace the foam. It could be my memory playing tricks on me, as I'm not 100% sure if this model had foam on the back of the shutter.

    The reason there was foam on the back of some shutters is that the space between the solid plastic light shield in film chamber and the rear lens element was quite large, and the foam was put in to prevent any possible light leaks - overkill maybe, but knowing Canon they did it for a reason sometime during the cameras production....Canon would issue a SMR (Service Manual Report) which would update any modifications/part number changes etc for a given model..

    What could also have happened is if your foam on the back door was crumbling it could have fallen between the rear lens element and the inside of the film chamber..

    I would suggest running a film through the camera, and if you are happy with the camera get it serviced by an old technician who has done them before...the way you have "cleaned" the residue form the shutter unit is only a stop-gap.

    To clean the shutter correctly you need to dismantle the shutter and clean all the shutter surfaces of sticky residue..

    Hope this helps

    Cheers