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Is there an opposite of soldering flux?

Discussion in 'Plumbing and Central Heating' started by PaulUszak, 20 Oct 2018.

  1. PaulUszak

    PaulUszak

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    This is a bit of a curve ball.

    Is there a substance that can be applied to copper to prevent the spread /adhesion of solder? So if you apply this stuff, the solder would be repelled and the copper remains clean? Sort of a masking fluid /tape that withstands a blow torch. Anything at all?
     
  2. Hugh Jaleak

    Hugh Jaleak

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    Solder will not stick unless the copper is absolutely clean, hence the need for flux in the first place. Copper will naturally develop a patina over time, if you really don't want solder to stick anywhere else, then don't clean the pipe any more than than you need to.
     
  3. Dan Robinson

    Dan Robinson

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    Use less solder..
     
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  4. oldbuffer

    oldbuffer

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    You could try "Snopake" or similar. Its supposed to work but I've never tried it.
     
  5. Bill RE

    Bill RE

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    Traditionally what was used by plumbers and model engineers to prevent solder sticking where not wanted was plumbers black. You paint it on the pipe then scrape it back to a straight line and the solder won't stick to the black stuff.

    Unfortunately I don't think it's widely available any more. It is easy if time consuming to remove dribbles of solder with wet and dry paper.

    There are a number of solder resists used for PCB making these can be found on amazon etc. I don't know if they can be used on pipes.

    Hope this helps.
     
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  6. nwgs

    nwgs

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    Cean and flux your fittings. Attach fittings together and wipe of any excess flux.

    Solder only runs where the flux is.
     
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  7. Dan Robinson

    Dan Robinson

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    Totes fam.

    Said it many times. People use too much flux and solder. That's what makes joints messy.
     
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  8. nwgs

    nwgs

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    My mate, he’s an ex army lad. Lashes flux on the fitting inside and out.
     
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  9. Nige F

    Nige F

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    I found RectorSeal Plumber's grease - Don't think it's suitable for Catholics, allegedly
     
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  10. endecotp

    endecotp

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    That’s the hard part. Out of curiousity I just checked the spec for an electrical solder resist and apparently it is designed for 275 C max.

    As above, apply less flux, wipe off excess flux before heating, apply less solder.

    Or use solder ring fittings - that’s what I’ve been doing and I get the opposite problem, they seem to have so little solder in them that the amount that appears at the end is visible only with a microscope; as a result I end up heating for longer than necessary.
     
  11. dilalio

    dilalio

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    It's the flux running out of the joint and down the pipe that takes the solder with it. I use laco but have heard some use a less runny flux to combat this problem.
     
  12. PaulUszak

    PaulUszak

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    Might plumber's black be like:-

    [​IMG] ?
     
  13. ianmcd

    ianmcd

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    never use flux inside a fitting, only on the pipe and the less the better and always wipe off after , and never brush a finished fitting with flux what is that all about ???
     
  14. What do you make of these things?
     

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  15. Dan Robinson

    Dan Robinson

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    Pointless overpriced nonsense (and I'm known to love toys).
     
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