How to best clean solder terminals/turrets, for resoldering

Discussion in 'Shock Brother's DIY Amps' started by itsGiusto, Sep 16, 2020.

  1. itsGiusto

    itsGiusto Tele-Meister

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    After having rewired my amp a few times now, I'm prepping it for a (hopefully) final rewire. I've sucked the solder out of every turret, but still many turrets are looking kinda cruddy, with brown residue on them, which I can only guess is old rosin:

    [​IMG]

    What's the most reliable/easiest method for getting terminals looking clean and shiny again, so I can ensure I get good joints when I rewire the board? Simply trying to polish with isopropyl alcohol on a cotton ball doesn't seem to be having an effect.
     
  2. Dan_Pomykalski

    Dan_Pomykalski Tele-Meister

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    I normally heat the turret up and then smack it against something like a block of wood. I’m also interested in the best method...
     
  3. Junior Little

    Junior Little Tele-Meister

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    Might try solder braid/wick.
     
  4. Dan_Pomykalski

    Dan_Pomykalski Tele-Meister

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    I can never get braid to work... it seems to just kind of smear the solder all over...
     
  5. itsGiusto

    itsGiusto Tele-Meister

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    Braid works for me in getting solder off, but not so much the brown residue. I'll say it is difficult, though to work the braid into every nook of the turret, however.
     
    Last edited: Sep 16, 2020
  6. Engine Swap

    Engine Swap Tele-Holic

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    I use a small nylon bristle paint brush, trimmed close, to act as a mini scrub brush. I use alcohol as a cleaner.

    I learned this trick from the ladies who did the mil-spec stuff at my last job.
     
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  7. jackal

    jackal Friend of Leo's Gold Supporter

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    I cut down an acid brush (available at any hardware store) until it's short and the bristles are stiff, and scrub with rubbing alcohol. Doesn't usually need to be cleaner than that.
     
  8. 24 track

    24 track Doctor of Teleocity Silver Supporter

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    have you ever heard of an S993-A?
    51oennrgLgL._AC_.jpg


    temperature controlled solder sucker , through ali express, banggood.com , you can get new different sized tips , and a new heating element , I use mine daily great for desoldering chips etc

     
  9. Peegoo

    Peegoo Friend of Leo's

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    If you don't want to spring for a rework gun like ^that^ one and you're having problems with desoldering wick, it could be you're using cheepo wick.

    One way to improve its performance is to swipe about an inch of it with a flux pen before you use it. Cheap wick often has little (or no) flux on it, so you can help it out by adding some. It does make a difference.

    The stuff I use is Kester 959T non-rosin liquid flux; it is very clean and leaves no crusty brown caramel coating. I keep it in a refillable felt-tip flux pen.

    If you buy liquid flux, make sure it's the type for electronics work and not for plumbing applications.
     
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  10. tubegeek

    tubegeek Friend of Leo's

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    Brass-bristled brush. Nearly zero cost at Harbor Freight in a set with a nylon and a stainless steel one.

    Also what @Peegoo said.
     
  11. tubedude

    tubedude TDPRI Member

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    Brass brush and Acetone. Work fast.
     
  12. Boreas

    Boreas Tele-Holic

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    Just a thought - would some sort of dilute acid work? It may help etch the metal.
     
  13. Engine Swap

    Engine Swap Tele-Holic

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  14. Dreadnut

    Dreadnut Tele-Afflicted

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    No need to clean at all before re-soldering, the terminals are nice and shiny. The brown is just old flux, it will melt and some will smoke away during re-soldering. If the new flux is rosin based it should clean away nicely with a small acid brush and isopropyl alcohol or acetone. If the new flux is water soluable, just clean it with hot water. If the new flux is "no-clean," just leave it be.

    Getting the best joints will rely on having the proper amount of heat and heat transfer to complete each new joint in about 3 seconds. Begin with a small drop of solder on your iron to help transfer the heat. Use the tip that most closely matches the size of the turret terminals, put it in contact with the terminal and the wire if possible. Max temp of the iron tip should be 650F.
     
  15. jhundt

    jhundt Doctor of Teleocity

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  16. dan40

    dan40 Tele-Afflicted

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    I have had some cheap braid before that would not take any solder. Applying a bit of flux to it as Peegoo mentioned does help quite a bit also. Don't forget to tin your tip even when using the braid. A dry tip will take forever to transfer enough heat to melt the solder so that the braid can suck it up.
     
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  17. dan40

    dan40 Tele-Afflicted

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    @itsGiusto ...just consider your turrets pre-tinned now. The brown residue will flake off with a small pick but it shouldn't hurt anything.
     
  18. chas.wahl

    chas.wahl Tele-Meister

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    Acetone's a better solvent for solder rosin than isopropyl, but it's also more dangerous (lower flash point, and more injurious when inhaled). There are different varieties of isopropyl, 70%, 91%, and the stuff that's lab-grade 99% -- but you're not going to buy that at Walmart. But you can probably order it online somewhere. There's also Everclear, (high-test ethanol) at the decently-stocked liquor store.
     
  19. ghostchord

    ghostchord TDPRI Member

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    my 2c:
    solder wick should work fine ... if it's not maybe the issue is the soldering iron a good temperature controlled one will help. wetting things a little bit with new solder to get a better thermal connection will help... there's also de-soldering pumps.
    upload_2020-9-17_20-50-50.png
    or just shake the solder off it when its wet, again you may need to add a little solder to get things flowing... You want to grab on with some plyers but somehow not lose the heat to said plyers. also as said you'll get a perfectly good connection re-soldering to these anyways.

    p.s. You'd think the rosin can just be burnt off, maybe think about it as coating them with new solder rather than getting the old crud off.
     
    Last edited: Sep 17, 2020
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