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Aemb04
Tinkerer
Username: Aemb04
Post Number: 11
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 28, 2013 - 08:51 am: | 
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Hello, I have a Yashica 635 with a Copal MXV lens/shutter. The problem is that the lens has fungus inside so I need to take it apart to try & clean it. Can I do this without taking the whole Copal shutter/lens assembly out? I noticed that the back of the assembly (inside the camera)the rear element has slots either side, is this element able to be removed by using these to unscrew it which would then would allow me to clean the inside as well. Thanks for any help. |
John_s
Tinkerer
Username: John_s
Post Number: 126
Registered: 07-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 28, 2013 - 09:26 am: |
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Yes both the rear element, and the front cell (this usually comes off in one piece with the two lens elements in a little cell) should just unscrew without dismantling. It's possible to unscrew the front cell and clean the front of the rear element through the open shutter - unless it's really bad when it will have to come out. The trickiest bit is re-threading the rear element back into the body. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 12
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 28, 2013 - 05:40 pm: |
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Thanks for the info John, any idea's on what's best to use to get rid of the fungus. Would Naptha or meths do the job? |
Nick_merritt
Tinkerer
Username: Nick_merritt
Post Number: 38
Registered: 06-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 10:13 am: |
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If it's fungus, you'll want to use hydrogen peroxide. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 13
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 01:25 pm: |
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Hello, at what concentration. Most chemists sell it between 3 & 9% would this do the job & do I need to clean the inside of the Copal shutter to kill any spores. |
Fidji
Tinkerer
Username: Fidji
Post Number: 56
Registered: 12-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 02:16 pm: |
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Most effective fungus killer is 50% hydrogen peroxide and 50% ammonia. After leaving the glass overnight, rinse in water and 'polish' lens with a micro cloth. Repeat if not completely removed.
Have heard that Ponds face cream does the same job, but have never tried it. If the fungus is of the 'spiders web' stage, it is usually too late for effective removal, and even light fungus will damage lens coatings to some degree, but that should not effect pictures if it is only on the front element.
Regarding spores in the shutter, fungus spores are in the air everywhere, so just stop them from growing by keeping lenses dry with a bag of silica crystals and regularly expose them to sunlight, rather than hide them in dark cupboards. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 14
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 03:05 pm: |
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Hi Fidji, When you say 50% hydrogen peroxide and 50% ammonia does the hydrogen peroxide also need to be 50% strength/concentration as I can only find 35% strength on the web in the UK, would this do the job. |
Fidji
Tinkerer
Username: Fidji
Post Number: 57
Registered: 12-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 05:11 pm: |
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I've never bothered about strength, just used what's available at the chemist, or in the case of ammonia, at the hardware store. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 15
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 29, 2013 - 05:21 pm: |
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Thanks Fidji that makes it a lot easier. Looks like I'm off shopping tomorrow. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 17
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 03, 2013 - 08:47 am: |
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Hi, I had a go at removing the lenses but after removing the front lens I could not see how to remove the lens just in front of the shutter blades (this is the one which is affected by fungus which appears to be at the back of it).I tried removing the rear lens but after unscrewing the ring it would not come out. If anyone can help that would be great. Cheers. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1342
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 03, 2013 - 08:41 pm: |
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The entire front cell, containing the first and second elements, unscrews out of the front of the shutter. With a rubber glove or something similar to give you a grip, you should be able to do this with your fingers. The front fascia panel has to be off of the 635 for you to reach the sides of the lens cell. |
Aemb04
Tinkerer
Username: Aemb04
Post Number: 18
Registered: 04-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 04, 2013 - 04:49 am: |
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OK thanks Rick, what's the best way to remove the fascia panel? |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1343
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, August 04, 2013 - 08:01 am: |
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Remove the front leatherette - it will probably be brittle on a Yashica, unfortunately - and you will find screws underneath that hold the front fascia panel on. The panel is made in 2 pieces, one is the outer perimeter and the second is the part around the lenses. You need to remove the inner part, but it comes off more easily if you remove the outer part first. Each is held by 4 screws.
Then you will find that the fascia panel hangs up on the little knob on the end of the shutter cocking lever. This is attached with a LEFT HAND THREAD: turn the knob CLOCKWISE to unscrew it from the lever. Once that's out of the way, you can lift the panel off. This exposes the shutter for service. |
