soldering

Discussion in 'Camera Building, Repairs & Modification' started by David Lyga, Sep 4, 2013.

  1. David Lyga

    David Lyga Subscriber

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    Suggestions for very tiny, delicate soldering please: type of solder, prevention of large drops forming, etc. Thanks. - David Lyga
     
  2. Tom1956

    Tom1956 Inactive

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    Soldering can be tough. The forming of large drops comes from the iron melting the solder from the end of the roll, but it doesn't "stick" to what you're soldering, causing the novice to keep feeding in more solder, and the iron keeps melting it till you have a big blob, but no actual joint. Before you touch the iron or gun to the solder area, make sure the heat tip is full temp before you actually make contact. When you see the existing solder start to melt, feed in your solder from the end of the roll at that time. Keep a paper towel or piece of paper to take the temperature of your solder tip. If it doesn't cause a burn mark on the paper, it's too cold to solder with. And if it's too cold to solder with, the novice keeps holding the tip on the part till he ruins the part. It might not be hot enough to melt the solder, but it's surely hot enough to ruin the part. The less time you have the tip on your solder area is the less likelihood you've fried your component.
     
  3. AgX

    AgX Member

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    Abundant additional, non-corrosive flux. I often use colophonium paste.

    A eletronically controlled, temperature adjustable solder iron is a treat.

    Most appropriate form of tip. You even might check this in cold state.

    Tinning each part on it's own before soldering would let you care better for each part than soldering both at once.
    And if one surface gives a problem you would not stress the other.
     
  4. ic-racer

    ic-racer Member

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    Very fine tipped soldering iron. Lower melting point better, but I find the differences in solder subtle and usually use whatever I can find.
    DSCF4531.jpg
    file-149.jpg
     
  5. BMbikerider

    BMbikerider Member

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    There is a very low temp solder available for model makers, so you could try contacting them It is generally used for soldering white metal die cast model locomotive construction kits. It is real solder but just has a low melting point but is a good electricity conductor. I believe the melting point is around 150F which is a lot lower than conventional lead/tin solder. As well as the solder you need a good acid based (Phosphoric)flux.
     
  6. DWThomas

    DWThomas Subscriber

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    For fine electronic work there are smaller diameter solders down around .020 or .032 inch diameter which are a little easier to control. The 1/16 and 1/8 inch stuff is closer to plumbing than modern electronic gear.
     
  7. paul_c5x4

    paul_c5x4 Subscriber

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    A lead based solder paste if you can find it. Servisol Soldamop (a copper braid) for soaking up excess solder. Tppex is also useful for masking off areas that you don't want solder on.

    An acid flux such as Bakers Fluid is fine for plumbing jobs and tin work, but not on small electronic jobs. A rosin based flux is best, although modern industrial soldering lines have switched to a Citric Acid based flux now that lead has been phased out from most solders.
     
  8. Truzi

    Truzi Subscriber

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    I'm no soldering wizard, but you definitely want a thin-tip on your soldering iron, and a proper electrical solder. I've only used one soldering gun that was any good, most took too long to heat up and this negated the advantage of the gun. I was quite pleased the first time I used an iron - it was so much easier to control.

    Most of my soldering has been on car wiring, and some basic electronics, nothing terribly small or delicate, though I have soldered wires to circuit boards (my only foray into digital, I put USB ports on a few of those "single-use" digital cameras).

    This may sound obvious, but be certain you are using solder meant for electrical connections. Once I had one hell of a time trying to solder some wires without melting everything nearby. My father assured me his solder was the correct stuff. I later learned he had handed me solder for plumbing - the ingredients melted at very high temperatures.
     
  9. David Grenet

    David Grenet Member

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    This. Magnification and practice also help. What are you soldering?
     
  10. Rudolf Karachun

    Rudolf Karachun Subscriber

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    Radio Shack. They have all you need for fine soldering.
     
  11. Tom1956

    Tom1956 Inactive

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    I guess I'm just good. Been using the same Weller 100-140 watt gun since 1969, and do everything with it. No touch too fragile for me. Lot to be said for some serious heat on the small things to get that solder melted, flowed, and hardened before the components even knew you were there. Those low-power irons can be trouble.
     
  12. lxdude

    lxdude Member

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    I have a few sizes of rosin core solder I use for electrical work, from the smallest I could get to a size proper for soldering 12 guage stranded wire. I use copper braid for de-soldering work. I prefer an iron for more delicate work, and a gun for heavier stuff. I always wipe off any old solder with a wet rag after the gun/iron first heats up, and re-tin it before proceeding. For technique, I make sure gun/iron is fully heated, then touch it to one side of the wire. After I think it's hot enough, I test by touching the end of the solder to the other side of the wire, and it will either melt and flow readily and I will proceed, or I get in idea how much more it needs. When it's hot enough, it will melt and flow very quickly, so you have to be ready to feed it if necessary, or remove pull the solder away. There's some feel and judgment to it. With some experience it will become easy.
     
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  13. Truzi

    Truzi Subscriber

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    That's a bit funny, as I believe the only gun I really liked was a Weller. It's not nearby, so cannot confirm it's a Weller. It is an old red one that was my grandfather's, and works surprizing well compared to other guns I've tried. I actually use it instead of searching for my iron (unless I need something with a fine point).
     
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  15. Tom1956

    Tom1956 Inactive

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    Wellers are black with a red trigger.
     
  16. Truzi

    Truzi Subscriber

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  17. Tom1956

    Tom1956 Inactive

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  18. lxdude

    lxdude Member

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    OK, you can sit down now. :wink:
     
  19. jp498

    jp498 Member

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    For small stuff.. (basically anything electronic), a soldering pencil rather than soldering gun. Clean then tin each item to be soldered (apply some solder separately). Use thinner solder, use rosin flux as it's not corrosive. Put a metal clip or something damp upstream of what you're soldering so heat doesn't flow into it and damage something.

    If it's surface mount components (electronic so small the components don't even have wire leads going into the circuit board), leave that for a pro.
     
  20. Paul Goutiere

    Paul Goutiere Subscriber

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    Refer to this video. It seems pretty straight forward.

    http://www.youtube.com/watch?v=I_NU2ruzyc4

    -Use a good quality soldering iron, about 25 to 40 watts with a small tip.
    Ideally it is nice to have one with temperature control, but lots of people don't.

    -Use the thin rosin core electronics solder.

    -Bring it up to heat and apply enough solder to the tip to make it shiny. Shake off excess, preferably somewhere safe. It's really hard to get
    solder out of cloth....like socks or pants. ( and eyes!! )

    -Clean the tip by wiping it quickly on a small pad of wet cotton cloth.

    -Place tinned iron to object you want to solder and hold it there until the heat from the iron heats the object. ( A tinned iron will transfer heat whereas
    a un-tinned iron won't. ) This should take seconds for a small object.

    -apply the solder to the heated object, not the iron.

    -the whole process should be done as quickly as possible so as not to allow the soldering iron to oxidize too much between operations.
    (you will see what I mean) Clean the tip, again, by wiping it quickly on a small pad of wet cotton cloth and apply a touch more solder to the tip.

    -allow to cool, for a moment before moving the solder joint.

    -Before you try to do this on something expensive, practice on scraps of wire or an old circuit board from some junked gadget.

    The smoke from the rosin is somewhat toxic, with acid and maybe lead etc. I use a small fan to blow the smoke away from me.
     
    Last edited by a moderator: Sep 4, 2013
  21. NedL

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    Depends a little on what you are soldering. If you are working on a circuit with heat sensitive components ( semiconductors, transistors, some diodes ) then you will need to take some care. A low wattage pencil iron with a high quality thin tip is good. You can tin the components but normally if they are clean good rosin core solder will flow on very thinly. The tip of the iron should be nicely tinned, and they "cure" and get better with some use... if you are not experienced it would be a very good idea to practice on something that does not matter until you get the hang of it. You want to get the tip of the iron wedged gently into the joint so that it heats all parts that need solder, and only apply the solder when the parts are hot enough for it to flow easily... sometimes you can get the flow to "pop" or start by just barely touching the tip of the solder to the iron, but for the most part you should not be using the iron itself to melt the solder. There's sort of a knack to knowing when to apply the solder, it becomes second nature after a while but takes some practice ( I've been helping my 12 year old daughter build a shortwave radio kit, and it brings back memories from when I learned around that same age! ) Radio Shack used to sell some nice soft .022 diameter solder, I think it was 62/36/2. These days I use an even finer solder from "qualitek" for small electronics.

    There are some other tricks for small neat solder joints that have to do with how you set up the components... if you are inserting a part in a circuit board, you can angle the leads so that they make good contact on the edge of the copper pad, and that will be the place to gently wedge the tip of the iron. Depends a lot on what you are doing, but the general idea is to have a point where contact is made by pressure, and not to try to use solder to bridge but have it flow neatly into the tiny space where there is contact.

    Good luck!
     
  22. Steve Smith

    Steve Smith Subscriber

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    I have had red Wellers.

    42260592.jpg


    Steve.
     
  23. AgX

    AgX Member

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    That one is great for repairig electronics from the 60's still with "flying" connections and for general houshold works, but I would not use it to solder something on my T-90.
     
  24. DWThomas

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    Ah yes -- my Weller gun is black with a red trigger. It was a much desired Christmas present for this compulsive tinkerer, circa 1956. I just used it the other day splicing some #16 stranded on a set of solenoid valves. But that was when "electronics" was Bakelite tube sockets with discrete components wired point to point between big solder lugs. IIRC, Weller is the maker of some pencil type irons that have a built-in temperature regulator that uses some magnetic properties to sense the temp; clever but expensive.
     
  25. E. von Hoegh

    E. von Hoegh Member

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    Don't get that Weller anywhere near anything with low voltage/low current electronics in it - which basically means everything today. It's stray field can fry modern solid-state stuff. That Dunning-Krueger effect will get you every time.:wink:
     
  26. ChuckP

    ChuckP Subscriber

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    I like having a spring loader solder sucker. It sounds like a Pentax 67 shutter when it fires off. Also I use a small Scotch brand kitchen cleaning pad to keep the tip clean.