[sdiy] Solder won't stick to old PCB

[cheater cheater]

Alcohol doesn't help against oxides.
Acid does, though.
Alcohol sometimes helps with biological residues, but it can
denaturize (?) them ('cut' the compounds like when you boil an egg)
and make them more difficult to remove, actually.

D.

On Sun, Sep 27, 2009 at 4:07 PM, John Alex Hvidlykke <john at hvidlykke.dk> wrote:
> Ah, the beauty of old electronics ;-)
>
> I have similar problems with most of my component collection, as most of
> them have been in storage in my various attics and cellars for some 20
> years.
>
> I will try if alcohol helps (on the soldering, that is). It sounds much
> easier than scraping the qxidation off with a hobby knife like I have been
> doing until now.
>
> \John
>
>> -----Oprindelig meddelelse-----
>> Fra: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl]På vegne af cs e
>> Sendt: 27. september 2009 02:53
>> Til: synth-diy
>> Emne: Re: [sdiy] Solder won't stick to old PCB
>>
>>
>> Thanks guys...I think that the joints are oxidized.  I'm not using
>> lead-free solder (I went and bought a boatload once I heard of ROHS a
>> few years ago) - and I'm sure my iron is hot enough.
>>
>> I'll clean it off with alcohol and try some flux...for now I got the
>> crucial part to stick.
>>
>> On 9/26/09, Graham Atkins <gatkins at blueyonder.co.uk> wrote:
>> > A few things. Don't try and use unleaded solder. Use conventional leaded
>> > solder on older equipment. The reasons the solder will not flow are
>> > either the
>> > iron is not at the right temperature, probably not high enough, or the
>> > most likely
>> > problem you have is oxide on the joints/tracks. Try cleaning with
>> > isopropyl
>> > alcohol on a cotton bud. Application of some additional flux (pen or
>> > brush) may
>> > also help.
>> >
>> > Graham
>> >
>> > On 26 Sep 2009, at 21:14, cheater cheater wrote:
>> >
>> >> Can this be because of ROHS? (i don't know)
>> >>
>> >> D.
>> >>
>> >> On Sat, Sep 26, 2009 at 9:03 PM, cs e <modulemania at gmail.com> wrote:
>> >>> Hi,
>> >>>
>> >>> I'm trying replace some components on a 20+ year old pcb, but my
>> >>> solder won't stick to anything (other components or existing joints).
>> >>> It just dries into little spheres and rolls off.
>> >>> Any advice?
>> >>>
>> >>> Thanks,
>> >>> Chris
>> >>> _______________________________________________
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>> >
>> >
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