Can solder, flux, etc go bad ?

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Hi guys,

If you keep solder and flux for years (say 3 - 5 years) can they go bad at
all ? I've had my coil of solder for about 5 years or more now and haven't
had a problem, but I wasn't sure (shows how often I solder anything).

Also, does thermal grease deterioate with age ? I mean in the tube not on
the heatsink.. (the latter I'm certain would deteroriate)

I have been using a cheap tube of thermal paste I bought about 3 years and
I'm thinking maybe if I got new stuff my chip miught not run so hot (half
the problem is lack of ventiallation, but it still runs kinda warm even with
the side off).


Re: Can solder, flux, etc go bad ?

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It does not go bad...
I'm using solder that's over 15 years's just fine...
not much to go wrong.
Same with thermal grease still in the tube...I've been using a large tube
for well over 15 years
no problems

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Re: Can solder, flux, etc go bad ?

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I haven't done any scientific tests with either solder or thermal
paste, but I regularly use solder over 10 yrs old and have not
noticed any difference. But there *are* significant differences
between different brands and grades of solder.

I use cheap no-name thermal paste from various sources for non-
critical applications in electronics. Some of them come in plastic
bottles rather than tubes. The 50-100 gram packs last a long time
and I've noticed that, at least with some of them, the solids tend
to separate gradually from the emulsifying liquid over the years.
I stir it again before applying, but I wouldn't use those for

Re: Can solder, flux, etc go bad ?

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Your solder will be fine.

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This can vary depending on the material and the tube it's stored in. As long
as it spreads evenly and isn't dry and "chunky" it should still do a good

Re: Can solder, flux, etc go bad ?

Skeleton Man wrote:
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I had one particular (big)roll of very thin solder at work,
which I used for about 30 years. Consumed about 30 percent.
I never noticed any degradation.
The roll retired at the same time I did, so its still around

Re: Can solder, flux, etc go bad ?

On Sun, 2 Sep 2007 16:00:46 -0400, "Skeleton Man"

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If you were to ask the solder manufacturer, yes solder flux
is less effective after a few years.  However for practical
purposes, it is still good enough in most cases to work
fine, you wouldn't notice the difference.

This excludes some water based solder pastes which not only
degrade quickly, but should even be stored at a low
(refridgerator or freezer even better) temp to improve their
short shelf life.  These are not products you or I would
generally use, not the kind of stuff you'd buy at Radio

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Over many years (not just 10) it might deteriorate if some
exotic formulation, but plain old silicone grease or a
synthetic oil with inert silver, ceramic or alumina
particles like Arctic Silver/etc should be fine.  

The biggest issue with some is that over time the solids and
liquids might separate so you have the clear (silicone
usually) oil pooled at the top.  It can't just be discarded
because then the remaining solids are thicker, and having
the proper viscosity is one of the things distinguishing
compound thin enough to spread evenly and thinly, and those
too thin which tend to pump out and separate more later
while applied and used in the /processor/ heatsink junction.
Thoroughly stirring the liquid back into the rest of the
paste is sufficient.

In short, if it looks ok, it probably is.  Because of the
separation issue present with silicone greases, for anything
critical I tend to prefer synthetic based greases like those
made by Arctic Silver, even if their lower tiered Alumina
grease, it still has the synthetic base.  IMO, the supposed
minor performance difference when it's newly applied is not
as important as longevity - thinking in terms of several
years use, for the life of the system.

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If the stuff you have is too thick or thin, or too much was
applied (it's hard to apply too little, unless the surfaces
were very irregularly shaped like with very old rough
extruded aluminum) then yes it might result in a few
(generally single-digit) degrees higher temp.  If it is not
too thick or thin, and since it's application on your "new
stuff" can't be very old yet, it is more likely that a
different thermal compound won't make much of a difference.

It's hard to generalize about an unknown paste situation,
basically I'm saying that the issue is not that your tube is
3 years old, it would be the other factors which effect
whether it is a little less effective but even this
difference is probably minor.  You could always reapply the
stuff you have and see if that makes a difference, only
putting a tiny bit on the center of the processor and
waiting for a few days of pressure and heat while running to
normalize the temp reading.  Often temp will go down about 3
degrees during this period (if all else is equal, including
room temp, fan speed, etc).

Generally if you feel the paste was applied properly and not
too thick or thin, the next step is to see if all parts are
running a little too hot or just specific parts.  If only
specific parts, try remounting their heatsinks with a fresh
application of grease, and if that is not enough you might
need a better heatsink.  If that is still not enough or if
several parts overheat, you may need increased chassis
airflow.  You don't mention the specific parts nor their
temp at full load though, so this is also a bit hard to
generalize then apply to a specific situation.  IOW, many
people are overly concerned about temps that are not too
high.  A CPU at stock speed should be fine at about 65C or
lower (these being full load temps), and a video card even
higher, I like to keep video at least under 80C but some
people have had their running slightly higher without any
ill effects that I know of.  Even so, it would be good to
get an 80C temp down lower, as it might also be a sign that
poor heat removal from the area is also making other parts
of the video card hotter, and heat degrades certain parts
like (especially) electrolytic capacitors over time.

We'd have to start with real numbers though, "IF" parts are
overheating one easy solution is to put a hole in the case
side panel and add an intake fan there.  This should help
more than leaving the side panel off, as leaving the side
panel off also disrupts the airflow from the bottom & front
quadrants of the case.

Re: Can solder, flux, etc go bad ?

Skeleton Man wrote:
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Ive been using very old solder and flux for years. It doesn't seem to me
that they go bad at all.

-- /

Re: Can solder, flux, etc go bad ?

Unused solder does not particularly age.  Solder joints in circuitry age due
to the thermal expansions and contractions.


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Re: Can solder, flux, etc go bad ?


Solder and flux do not go bad although flux may solidify but it can still be
used.  Lead solder really shouldn't be used on PCBs designed for Lead-free
solder and vice-versa (same with lead/lead-free components).

One thing though, if you have to use flux on a PCB make sure you clean off
the residue.



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