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electronics solder

ok, so seeing that nothing on the internet will give me a straight answer to this; i have about 500 grams of multicore solder that i found, and im wondering if that kind of solder is ok to use in electronics, or does it have to be 60/40 rosin core type?
 

KrisBlueNZ

Sadly passed away in 2015
AFAIK, "Multicore" solder just has multiple cores of flux inside it. That description doesn't tell you what metals it contains, or the percentages of each. That information should also be marked somewhere on the roll.
 
Kris is correct what you post is vage if the spool dosent list info than dont use it for electrical,in solder the first number is the % of tin the flux can be either acid or rosin (newer fluxes for electrical use are different comp.) if what you have is acid flux it is likely 40/60 good for general soldering, the way to tell if acid flux is cut end clean then heat and see if it has a acidy or sharp smell
 
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(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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I'm not sure that I've ever seen a multicore solder for other than electronic use.

However, the places I go only sell solder for electronics use :)

Even if my first observation was correct, you would at least want to know if it is a tin/lead or a lead-free solder because they behave quite differently.

What is the diameter of the solder. If it's 1mm or less, it's unlikely to be for anything other than electronics. That answers the main question even if it leaves others unanswered.

One thing you can do is to melt a puddle of the solder. Have a blob about 6mm wide and melted. Then get a screwdriver and poke i around as it cools.

one of three things will happen (for leaded solder):

1) As it cools it will get "pastey" and you'll be able to shape it while soft and even smear it out.

2) It will go from liquid to a solid almost instantly (say, over the period of a second) at some point

3) It will go very quickly from a liquid to a solid at some point, but you will be able to mush it around for a couple of seconds.

(1) is for soldering downpipes. It may be 50/50 or even further away from the ideal.

(2) is 63/37 - right at the eutectic point for lead and tin. This is very good for electronic work

(3) is 60/40, quite typical for electronics work.

Regardless of what you have, if it is thin, my prediction is that it will behave like (2) or (3).

If you have a temperature controlled soldering iron you should be able to estimate the melting point. That will tell you if it's leaded or lead-free (which almost always have a significantly higher melting point).

Incidentally, solder melts like it cools. If you can estimate the range of temperatures over which it remains between solid and liquid (it's a bit subjective) then you can estimate (or maybe postulate) the composition.
 
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