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Monopix
Tinkerer
Username: Monopix
Post Number: 117
Registered: 11-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 29, 2010 - 05:45 am: | 
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I'm having trouble soldering onto a battery contact from a Minolta Hi-Matic. Never had problems before using standard solder but I just can't get this one to take the solder. Not sure what the contact is made of either. Any tips? Would silver solder be better? I've never used it and not sure of it's benefits other than low resistance. |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 20
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 29, 2010 - 06:08 am: |
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Some materials are hard to solder. You may try a re-tinning compound for long-life solder tips, it has some pretty aggressive flux that can help soldering onto non-cuprous metals. You can buy it in electronic supply stores.
Remember to clean after soldering - use some isopropyl alcohol to wash away flux residue, or corrosion may start aaround your new solder joint.
Marek |
Harryrag
Tinkerer
Username: Harryrag
Post Number: 218
Registered: 05-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 29, 2010 - 08:53 am: |
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From experience I know that some metals like nickel plated battery cases do not accept regular solder, scraping off the thin layer of oxide and using flux immediately is worth a try. Also after a battery leakage the metal surfaces of the contacts are not solderable, and especially if the soldering joint cannot be heated enough because of the plastic melting away instantly soldering battery cases is always a matter of trial and error. |
Silversurfer
Tinkerer
Username: Silversurfer
Post Number: 12
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 29, 2010 - 01:52 pm: |
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Are you sure the metal is compatible with solder? Sounds like it may be an aluminium alloy? Was the orignal wire crimped on?
Silver solder is much stronger than 'soft solder' but needs a lot higher temp. (higher than a solder iron can put out) I use a tiny blow torch and the flux is quite corrosive. Tiny parts can get overheated or blown away by the torch, but if successful, it is a strong joint. |
Mndean
Tinkerer
Username: Mndean
Post Number: 216
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 29, 2010 - 10:05 pm: |
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Stainless steel battery contacts are notorious for difficulty in soldering. Conductive epoxy may work better for that sort of material. |
Charlie
Tinkerer
Username: Charlie
Post Number: 236
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 30, 2010 - 06:04 am: |
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I second conductive epoxy. Available at auto parts stores in repair kits for rear window defrosters. |
Glenn
Tinkerer
Username: Glenn
Post Number: 765
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 30, 2010 - 09:19 am: |
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Be aware that silver containing soft solders can exhibit better wetting characteristics on certain steels and alloys - the flow characteristics of these solders are generally inferior to tin/lead alloys and the modern 'health and safety' imposed electronic solders. Hard silver solder alloys of the 'Easy-flo' variety melt at far too higher temperature for electronic circuitry use, although are useful for repairing damaged stainless steel strip contacts - if you remove them from their plastic environment first! |
Ron_g
Tinkerer
Username: Ron_g
Post Number: 11
Registered: 07-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 30, 2010 - 09:50 am: |
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How would one remove this "conductive epoxy" if the time ever comes?I want to be thinking about this before I am confronted with it ).Ron G |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 22
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 30, 2010 - 11:00 am: |
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I hate conductive glues, they never seem to have stable resistance, they HAVE a noticeable resistance in the first place, and when you need them off, you can't. Also, many suck moisture from the air...
For connectors that really won't accept solder, if there's an accessible tab, you could try crimping. There are thermocouple crimping barrels that are available in sizes compatible with camera work, crimping tools, however, are huge. warning I never used this on a camera, but it's a solution of choice for connecting wires to e.g. steel, CrNi heating strands, etc.
Marek |
Monopix
Tinkerer
Username: Monopix
Post Number: 118
Registered: 11-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 01, 2010 - 02:24 pm: |
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The battery contact was originally soldered and the other contact still is so, originally, it was solderable. The camera has suffered a leaking battery which caused the original wire to corrode. In replacing the wire, I came up against this problem. Harry's comment that contacts are not solderable after a battery leak is interesting but I don't understand the reason.
I can remove the contact completely and I've tried using a small blow lamp to make sure the contact is hot enough but still no joy. I did think about the conductive glue but it just doesn't seem the right thing to do, but, if nothing else works, I'll try it.
I'm still thinking silver solder might be an answer and might get some just to try. |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 245
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 01, 2010 - 02:59 pm: |
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I'd guess that the problem is chemical: something exuded by the corrosion renders the metal unsolderable.
There should be some way to clean it before soldering. Harry mentioned using flux; this might be a solution. (I know that if you use acid flux, you must be sure to get it all off after soldering or you'll get further corrosion.) Maybe Harry can elaborate on this. |
Silversurfer
Tinkerer
Username: Silversurfer
Post Number: 13
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 01, 2010 - 03:32 pm: |
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Soldering calls for chemically clean metal. You must have it abraded to be shiny/showing bright original metal. If it has any trace of 'green' batery corrosion the solder will not stick, it will roll off like ball bearings.Heating for soft solder is best via a copper 'bit'. A flame can oxidise the clean metal.There is a 'solder paint' used by vintage car body repairers' for 'lead filling' this will really help soft soldering, but it is corrosive.
But, for silver (hard) solder the flux powder is mixed with a little water and applied to the job like a paste. The flame 'fizes' the paste to 'stick' and inhibit oxidisation allowing the silver alloy to flow. Of course the job must be isolated from delicate adjacent parts/plastics etc.If you want to try silver solder and you are in UK I could send you a little easyflow flux powder and a little solder strip?
silversurfer |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 247
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 01, 2010 - 03:47 pm: |
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Except that silver solder is waaaaay overkill for this simple soldering job (only a simple wire connection, not a mechanical attachment), and besides it requires a lot more heat which is likely to melt nearby plastic parts. |
Silversurfer
Tinkerer
Username: Silversurfer
Post Number: 14
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 01, 2010 - 05:00 pm: |
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Yes,I'd second that, siver solder is best suited to making strong mechanical joints. Unless you are careful/skilled in it's use you end up destroying the component. I offered the advice and materials on silversoldering. However, as it's only an electrical wire to join,it will probably be melted in the task.
Shiny clean metal, tin the wire and a good hot iron and it should take with soft solder. Silversurfer |
Harryrag
Tinkerer
Username: Harryrag
Post Number: 221
Registered: 05-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 03:30 am: |
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Silversurfer mentions the most important point, metal has to be clean, and this is what the material to be soldered is not when it got in touch with a leaking (mercury) battery. I am not a chemist, but I guess the battery fumes have an effect on metal surfaces. Years ago when I used to restore vintage tube radios and amplifiers, I used rosin-core solder for electronic purposes and slightly scraping off the grime from second hand tube sockets was enough to make them soldedrable again. But nowadays the solder smells differently when heated, and I think the solder plus flux core is somehow eco-friendy and less toxic, but often the solder just drops off the joint like sweat beads. I have found useful what is usually considered unsuitable for electronics, and that is wiping off the unsolderable metal surface with Rothenberger (or Weller, Felder, etc.) soldering fluid, all of them contain more than hydrochloric acid, I bought a very small bottle at a DIY store ages ago). I only use it very sparingly and in most cases solely for cleaning purposes as remaining residue will probably eat away the copper strands of thin wires in the long run. I use it in cases like the one you describe and when all else fails. |
Ron_g
Tinkerer
Username: Ron_g
Post Number: 12
Registered: 07-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 03:53 am: |
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I just replaced the capacitor and battery pack in an old Mecablitz 106 strobe that I bought in Germany in 1961 and that soldering fluid would have come in handy there.I never heard of it before.
Seems you cannot cut the wires back far enough to get a good surface to solder to.
I still do some repair on the old tube gear and I get amps from time to time with tube finals that need circuit work.About all that I can do short of replacing the wire is expose the bare metal and tin it good but some things are more difficult to replace as you cannot find replacements.Ron G |
Charlie
Tinkerer
Username: Charlie
Post Number: 237
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 06:06 am: |
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I had a very good experience using the conductive epoxy sold for rear window defroster repair kits. I ran a test using a 100 ohm resistor measuring resistance without and with a piece of copper wire butt epoxied on and could see no difference. I then used it to attach a wire from the battery cavity of an Oly GSN to its meter and over a couple of years and several rolls of transparency film the exposures were fine. The epoxy repair also worked fine on my rear window defroster for the several more years I kept that car. Both sold now. |
Monopix
Tinkerer
Username: Monopix
Post Number: 119
Registered: 11-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 11:14 am: |
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I don't think cleaning is the issue here as I've gone to some lengths to get it clean including using steel wool as I'd use for plumbing. I've also tried using plumbers flux as well but still no joy. As I said before, I can remove the contact completely out of the camera so no chance of melting anything I shouldn't and I've made sure the contact is hot enough to melt the solder (that is, it's not just melting when it's in contact with the soldering iron).
My feeling is this is a plated steel contact and the plating, which would make it solderable, has gone. Either from the action of the leaking battery or from me cleaning it too vigorously. So I'm probably trying to solder direct to the steel which, normally, won't work. I seem to remember that you can solder to steel with silver solder which is why I was considering it.
Silversurfer. Thanks for the offer. I've found someone locally who can supply silver solder so I'll get some from them. |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 249
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 11:29 am: |
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You should be able to solder directly to steel using ordinary (i.e., tin/lead) solder; at least I know I've done it. I don't think you got the surfaces clean enough, although I would have thought the plumber's flux (acid) would have done the trick. Maybe another round of cleaning is in order? |
Silversurfer
Tinkerer
Username: Silversurfer
Post Number: 15
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 02, 2010 - 03:22 pm: |
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David is right, you can certainly solder direct onto steel. 'Tinplate' is steel 'coated' with tin, an element of soft solder. Wire wool will shine up the metal and it works great on copper but for steel I use emery paper/tape. If I was doing this I would file the solder iron tip to be bright copper and tin it, then get my little Dremel with a grinding stone and roughen the surface to a bright, clean finish and if it is steel IT WILL take. If it is nickle/chrome palate'd then it may not take, unless you break through the plating.
Plumbers flux was traditionally talow, for lead pipes. Sheet metal workers flux was 'killed spirits' (bakers fluid was the trade name)basicly hydrochloric acid with,I think zinc (I am thinking back a loooong way to my apprenticeship here!)It is very corrosive, but really helped 'tin' the steel.
No good for electrical wiring as it will eat the copper wire! If you feel you must try silver solder try 'tinning' the steel with silver then try applying soft solder to bond the copper wire, good luck, silversurfer. |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 24
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 03, 2010 - 01:58 am: |
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grrr, I posted yesterday and it ate my post.
If the leaking battery was a mercury one, and the contact is anything non-iron, then there's a chance, that the surface is an amalgam now.
Marek |
