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goamules
Joined: 07 Jul 2007 Posts: 15 Location: Arizona
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Posted: Fri Aug 03, 2007 6:54 pm Post subject: Lens disassembly for Cleaning - How on Wollensak Velostigmat |
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I've a 7 1/4 inch Wollensak Velostigmat IV f6.3 on my first Speed Graphic. There is plenty of dust (and perhaps lube spatter) on the inside.
I've unscrewed the front and rear assemblies off the barrel/shutter. Easy. But how do I get between the elements of each assembly? That's where I see all the dust. I don't see any screws, I've looked with a loupe. Is this as far as I can go?
thanks for any help. |
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Les
Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI
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Posted: Fri Aug 03, 2007 11:08 pm Post subject: |
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There were three ways lens makers assembled lens cells.
The early version had the interior half unthread from the front half. This was common with Pre war lenses. Look closely at the threads and brass of the interior section to see a seam somewhere.
The next easiest, but not necessarily easy, were front loaded cells. The retaining ring is the front bezel. Look how the front bezel meets the outer area, if there's an internal thread then that's what you have.
The best way is to find a white rubber stopper and carve a concave section on the top or bottom to allow the stopper to clear the glass and touch the bezel. Then Squeeze and turn. Stoppers are sold for this purpose at www.micro-tools.com
the last way is where they assembled them from the rear, then "burnished" or rubbed the metal over the edge rear cell, in effect permanently sealing it. Professional repair people usually mount these in a metal lathe and slowly cut part of the housing off and then have to fabricate a new way to hold the lens elements in after cleaning.
SKGrimes no longer does this work, but they still have a page up showing how it was done when Steve was still alive.
http://www.skgrimes.com/popsci/burnish/index.htm _________________ "In order to invent, you need a good imagination and a lot of junk" Thomas Edison |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Sat Aug 04, 2007 9:23 am Post subject: |
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In the post http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00LJY7 Michael Harris describes how he "opened and closed" a sealed brass lens in his second entry in the thread. _________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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goamules
Joined: 07 Jul 2007 Posts: 15 Location: Arizona
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Posted: Sat Aug 04, 2007 2:08 pm Post subject: |
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Thanks both. This lens appears to be prewar, I'm just guessing by the look compared to 1920s catalog pictrures at cameraeccentric.com.
I've taken the front off again and don't see much of a line/crack. I'll post a picture later today for yall to see. |
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