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Olympraf
Tinkerer Username: Olympraf
Post Number: 3 Registered: 08-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Saturday, November 27, 2010 - 06:05 am: |
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Hello, I just bought a Electro 35G (with a working battery!) but the rangefinder did n't work. After camera top removal I found that the little mirror was disconnectet from the support. Which cement or glue is safe for this repair: epoxy, cyanoacrylate?? Raf |
Greyscale
Tinkerer Username: Greyscale
Post Number: 28 Registered: 07-2010
Rating: N/A Votes: 0 (Vote!) | Posted on Saturday, November 27, 2010 - 03:08 pm: |
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I would use epoxy. Cyanoacrylate, while providing a strong bond, has a low shearing strength and also gives off fumes which may damage the half-silvered surface of the mirror. |
Sevo
Tinkerer Username: Sevo
Post Number: 71 Registered: 09-2008
Rating: N/A Votes: 0 (Vote!) | Posted on Saturday, November 27, 2010 - 03:14 pm: |
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Never use generic cyanacrylate on a assembled camera - the common air/water curing variant emits vapours that can irrecoverably fog acrylic (and you can hardly find a camera without some acrylic bits) across several centimetres. I'd use thickened epoxy - there are some "gel" variants sold for model making, but you can just as well mix SiO2 (silica) filler to the desired consistency with any kit epoxy. |
Denny
Tinkerer Username: Denny
Post Number: 58 Registered: 08-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Wednesday, December 01, 2010 - 06:49 pm: |
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I have a similar challenge on a Kodak 35 RF split image mirror. Is cyanacrylate the same as "super glue" or "crazy glue"? In doing an archive search I have found gelled super glue and pliobond often suggested. I have both, as well as JB Weld (epoxy). Out of these 3, epoxy (JB Weld) would be the preferred material? Thanks |
Mareklew
Tinkerer Username: Mareklew
Post Number: 203 Registered: 03-2010
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, December 02, 2010 - 11:05 am: |
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Almost all super glue/crazy glue is cyanacrylate. Pliobond would be worth a try, but be careful with plastics - it can eat at them. I found clear nail polish to be a very good glue for bonds that should stay put, but should be breakable if need be. Same note on plastics. For metal-metal or metal-glass you look for a mild solvent based glue. Solvent glue is in principle just some plastic dissolved in appropriate solvent and cures by evaporating the solvent. Advantage is, that if you add solvent again, the process can be reversed (even if it might be very slow process). Disadvantage is, that if the substrate is made of plastic that the glue's solvent dissolves, you might ruin the parts (although properly applied glue will in this case make a perfect binding, albeit an irreversible one, by "melting" both parts together). Epoxy type glues cure chemically. They need not be aggressive against the substrate (and most are made to be safe on typical plastics), but the curing process is one-way. Once cured you can only file the glue off (okay, there ARE ways to break it, but not really feasible in scope of camera repair). Marek |
Mareklew
Tinkerer Username: Mareklew
Post Number: 204 Registered: 03-2010
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, December 02, 2010 - 11:08 am: |
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By the way: to attach a mirror, a piece of double-sided thin carpet tape is almost perfect. Just don't apply it to the full area - a few pieces at few critical spots will suffice and if needed you can still pry it off (most of the time at least). If applied to full surface it will be stronger than glass... Marek |
Denny
Tinkerer Username: Denny
Post Number: 59 Registered: 08-2009
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, December 02, 2010 - 05:47 pm: |
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Thanks again Marek. I did see the double stick tape in the archives as well. I have some and will give that a try first. On this camera, it is regular mirror (not front surface) and attaches at two points on a metal plate that pivots. Should be very simple to get in the correct location. Plus I won't have to wait for anything to dry/cure. |