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rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 03, 2005 - 09:40 am: | 
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I've finally pinned down the actual chemical formula for the cigarette lighter fluid we're so fond of as a camera cleaning solvent.
Solvent Naphtha is a blend of aliphatic hydrocarbons, primarily n-Octane and n-Nonane (C8-H18, and C9-H20, respectively). These are members of a family that extends from Methane through Butane as gases, up through Paraffin waxes to Polyethylene plastics. It is a liquid (at room temperature) where the number of Carbon atoms in each molecule is between about 5 and 15 or so.... so Naphtha is basically the standard representation of the liquid form of this family of chemicals.
I hope this may help our colleagues in other countries to accurately identify and obtain equivalent solvents.
rick : ) = |
RJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 08, 2005 - 04:58 pm: |
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That's correct Rick. If we could upload, I'm sure you would have drawn the chemical configuration for C8-H18 -- C9-H20 perfectly ;) |
John Tomaszewski
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 25, 2005 - 09:10 pm: |
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It can be done with text, C8-H18 is:
H H H H H H H H
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H-C-C-C-C-C-C-C-C-H
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H H H H H H H H
Actually the reason I'm posting is that I was confused about this as well. I went to Lowe's and Menard's and all I found was pressurized butane (C4-H10, which boils at about the freezing point of water) lighter fluid. And I've always heard the disposable lighters referred to as butane lighters. I couldn't figure out why I people were talking about using lighter fluid as a solvent when it's a gas at room temperature. Thanks for the info.
As an aside, in the Tomosy books he refers to an "acceptable" shortcut of flooding with lighter fluid to clean out old lube and dirt but I can't quite picture how one does this. Is he talking about taking the bottom plate off, holding the camera upright, squirting lighter fluid up into the works, then letting it drain down and out? What kind of volume are we talking about? Any description from someone who's done this would be appreciated. I have a couple of cameras that I'm working on with slow shutters and I think this is the next thing I should try but am a little reluctant to just "hose them out". Thanks in advance.
John T. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 26, 2005 - 01:02 pm: |
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John -
The word "flooding" is a little misleading. The amount of fluid you use may be quite small and applied in just a few places. Like so many things the answer is "it depends."
On a leaf shutter that is running slow, this is usually done by removing the front lens elements and the control rings and then putting drops of solvent on the parts of the mechanism that are sticking. Commonly the problem is in the bearings and gears of the retard escapement assembly. You then have to use compressed air to blow out the solvent and old oil. Just letting things dry will redeposit the same old oil back where it was.
If the blades are sticky, you have to wipe them with a paper towel (or similar materal) dampened with solvent. This is done repeatedly until the blades are clean.
You shouldn't pour large amounts of solvent into the shutter unless you can remove the shutter from the camera. Some people soak the shutter in a bowl of solvent instead of pouring the solvent through the shutter. You always need to use compressed air to blow the solvent out and not just soak the shutter and let it dry. However, cleaning the shutter this way may not work. If there is a lot of contamination it just ends up moving it around inside the shutter and it will eventually cause problems again. In the worst case you have to completely disassemble the shutter and wipe each piece off individually.
Also, there are a few shutters that need some internal lubrication. This is usually on the cams and control rings but may also be on levers and latches and things like that. Soaking the whole shutter can leave it without this necessary lubrication.
Sorry to be so vague but many times its a matter of try one thing, then try the next, until you locate the source of the problem. |
John Tomaszewski
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 07:23 am: |
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Dan,
Thanks for the input. I have a few of these type shutters that I should be getting to soon and that helps a lot.
Can I ask though, what about cloth-type curtain shutters, where it's not the shutter itself that is running slow but the gearing. For instance, I have a Spotmatic that I tested and the shuttter speeds are slow. Increasing the curtain tension made a little difference but not much. Henry T. mentioned in another post and associated emails that a good cleaning should restore it close to factory speeds but I'm just not clear on exactly how/where to apply the solvent (top, bottom, front, back, etc.).
If I could just see someone do it once I'd be all set but in lieu of that I thought a couple descriptions like yours for the leaf shutters would help. Thanks again. |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 09:41 am: |
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On the Spotmatic you need to clean the ends of the curtain roller shafts. With the top and bottom covers off you can see these. Just put a drop of solvent on each and work the shutter, then blow them out. It may take several tries and you may need to put a tiny bit of oil back in the bearings.
There is also a gear on the bottom that is driven by the closing curtain. This gear is what releases the mirror return. It should be cleaned also.
If it's the slow speeds that are off you probably have a sticky escapement. That is located underneath the mirror box and is difficult to reach without removing the mirror box. I usually try injecting some solvent with a hypodermic needle through one of the holes in the bottom plate.
Best of luck.
Dan |
John Tomaszewski
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 28, 2005 - 05:53 am: |
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Thanks again Dan, that's exactly what I needed.
John T. |
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