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Thread: Opening front group of a Wollensak 190mm enlarging lens?

  1. #1
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    Opening front group of a Wollensak 190mm enlarging lens?

    I just picked up one of these that has slight fungus in the front group. It looks like the front group may unscrew from the barrel but it doesn't, at least with the force I can apply by hand. The front trim ring (with the lettering) looks to be threaded but it didn't give with my hollowed-out rubber stopper. I haven't tried seeping acetone into the threads yet.

    Has anyone ever been inside one of these? Is removing the trim ring the right way in? I'd really like to clean it up as the coatings are really nice, it would be a good lens for the 5x7 conversion I'm planning for my Beseler 45.

  2. #2

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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    It’s probably glued shut. I’ve had a few old lenses that were. Try painting the ring with naphtha and letting it soak in a bit.

    Acetone would probably work, but it will likely eat the paint. I’d save that for desperate measures.

  3. #3
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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    Thanks for the reminder about naphtha/Ronsonol. I’ll definitely try that first, and will test carefully before trying acetone or ethyl acetate.
    Last edited by Steve Goldstein; 2-Oct-2018 at 12:04.

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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    Just wanted to close the loop on this. The metal (yay!) trim ring was lacquered/painted in place. I removed most of the lacquer/paint with a series of Q-tips soaked in Ethyl acetate (the essential ingredient in most nail polish removers, but I have the pure stuff). Next I allowed more solvent to seep into the threads, after which I was able to unscrew the ring using a hollowed-out rubber stopper. This gave me access to the front element, which came out easily so I could clean out the fungus. The glass wasn't etched and I'm now a happy camper.

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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    I didn’t think about ethyl acetate. That’s a good idea! I’ll have to add that to my chemical cabinet as an intermediary step.

    You can’t have enough cleaners and lubricants for this hobby!

  6. #6

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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    Let's hope that the lens' quality is worth the effort. Even if not you've gained some useful skills.

  7. #7
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    Re: Opening front group of a Wollensak 190mm enlarging lens?

    Quote Originally Posted by jim10219 View Post
    I didn’t think about ethyl acetate. That’s a good idea! I’ll have to add that to my chemical cabinet as an intermediary step.

    You can’t have enough cleaners and lubricants for this hobby!
    It's not as widely available as acetone, but McMaster-Carr has it.

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