Does solder really expire?

[nbritton]

Does rosin core solder really expire? I was thinking about getting a 1 lb roll of Kester 44 Rosin Core Solder 63/37 .020" but I'm worried it will expire long before I use it all up. The 3/4oz rolls are $10 each with shipping, so it's way more cost effective to buy the 1 lb (16oz) roll at $39.

[djQUAN]

The alloy itself doesn't but as far as I can tell, the flux gets less effective.

I have a 2kg (4.4lb) roll of Alpha metals solder nearing its spool end (had it for almost 10yrs) and I recall its flux was more effective back then. Still useable though except for oxidized part leads.

[nbritton]

How long does it take a typical hobbyist to go through a 1 lb roll?

[jwm_]

Does rosin core solder really expire? I was thinking about getting a 1 lb roll of Kester 44 Rosin Core Solder 63/37 .020" but I'm worried it will expire long before I use it all up. The 3/4oz rolls are $10 each with shipping, so it's way more cost effective to buy the 1 lb (16oz) roll at $39.

I still have a kester roll that is probably 30 years old by now that I took from my dads workbench. (I have been through many rolls of solder since then of course, this one just hasn't been used as fast and is stick bouncing around). It works great. Solder going bad is not something you need to worry about as a hobbiest. At worst you swipe with a flux pen first which you often want to do anyway.

Solder expiration dates are more for industrial production houses, where you have an assembly line that needs materials that behave exactly the same way each time, they may fully expect and know the rosin stays good for 30 years, or even gets better, but will put an expiration date of 10 years so they can't be sued if it doesn't quite act exactly as a new roll would when used at an industrial scale. Or if a huge NOS batch of your product turns up you are not on the hook for support of something you stopped making ten years ago.

You will eventually use it up, or your kids will, or it will become a coveted treasure from before RoHS made lead solder hard to come by. Go for it.

[nanofrog]

As a hobbyist, all you'll really need to do is store it in a cool, dry place, and it will last you for years (beginning to end of spool). Keeping the wire closed over from tinning keeps the flux core cut off from air also helps.  Worst case, if you find it's not performing satisfactorily, just cut off a couple of feet and see if that doesn't improve matters (cutting back to fresh, unexposed flux). 

So go ahead and buy the 1lb roll. 


FWIW, I've got a small tube that's ~30yrs old (RadioShack), followed by some Kester that's over 20yrs old that I'm still using.

I also keep liquid RA flux on hand for use in a refillable brush pen (MG Chemicals Rosin 835 comes in hobbyist friendly sizes). Cheaper than disposable pens.

[JoeN]

Does rosin core solder really expire? I was thinking about getting a 1 lb roll of Kester 44 Rosin Core Solder 63/37 .020" but I'm worried it will expire long before I use it all up. The 3/4oz rolls are $10 each with shipping, so it's way more cost effective to buy the 1 lb (16oz) roll at $39.

$39?  Are you kidding me?  Buy it here:

http://www.all-spec.com/products/KW4410.html

[bills]

The biggest problem is not being able to find it after a few years.
Example= my main water feed broke yesterday and I have several rolls of 95-5 solder but no idea where I put it.
Had to buy 1lb. of the new silver solder that is the crappiest solder I have had the displeasure to use.
I have 20- 25 year old solder that works just fine ( keep it sealed and it will last for years)
 

[bills]

When you are done using the solder crimp the end to seal the flux inside.
will last for a long time.

[nbritton]

$39?  Are you kidding me?  Buy it here:

http://www.all-spec.com/products/KW4410.html

That's for 0.031" diameter. Isn't that too big? Dave says in his video to use 0.020" (0.5mm) or less. Should I get two sizes instead, i.g. 0.015" for SMD and 0.025" for through hole? Couldn't you double, triple, or quadruple up the 0.015" to make larger diameter solder? Someone described the 0.015" as 'stiff thread', will the solder hold itself up without drooping?

[Ian.M]

Also see https://www.eevblog.com/forum/beginners/solder-shelf-life/

If you are packing it away for long term storage, it *MAY* be worth melting the end into a little ball to seal it.  Otherwise if you are using it up at a normal rate, you are unlikely to ever experience any noticeable degradation of the flux core.

[nbritton]

At worst you swipe with a flux pen first which you often want to do anyway.

I was planning to buy a flux pen anyways, Dave says you can never have too much flux, so cool. My only trouble now is figuring out what size diameter to get.

[jwm_]

$39?  Are you kidding me?  Buy it here:

http://www.all-spec.com/products/KW4410.html

That's for 0.031" diameter. Isn't that too big? Dave says in his video to use 0.020" (0.5mm) or less. Should I get two sizes instead, i.g. 0.015" for SMD and 0.025" for through hole? Couldn't you double, triple, or quadruple up the 0.015" to make larger diameter solder? Someone described the 0.015" as 'stiff thread', will the solder hold itself up without drooping?

It's a personal preference thing, I much prefer thicker solder in general, I'll break out the thin stuff occasionally but very rarely. I like being able to spend less time with my iron on the joint and find depositing a couple mm of the thick solder to a cm of the thin to actually be easier to control due to the stiffness of the solder and not having to reposition my hands as much.

So, i disagree with with him on the thin solder thing. I did however follow his advice to get a chisel-tip rather than a conical one and couldn't be happier with the switch.

[tautech]

No it doesn't. Got 40 yr old solder that works just fine.
There was another recent thread on this same subject and general opinion was solder lasts decades.

[nanofrog]

$39?  Are you kidding me?  Buy it here:

http://www.all-spec.com/products/KW4410.html

That's for 0.031" diameter. Isn't that too big? Dave says in his video to use 0.020" (0.5mm) or less.

Depends on what you're using it for. And as mentioned, there's personal preference involved (you'll encounter plenty of joints that could be done with multiple diameters within a couple of seconds or so).

IME, 0.031" is excellent for PTH and larger SMD joints, but it gets harder to control the amount of solder the smaller the package/joint for most people it seems (i.e. easier to control larger distance than small ones within a couple/few centimeters max for big joints). Ideally, you'd have multiple rolls of different diameters, but that's expensive when just starting out. So for a single roll that's close to a one-size-fits-all, 0.020" is Dave's pick as a reasonable compromise for most people. I'm actually partial to 0.025" for this as it's faster to feed larger joints (PTH), but that's me. Regardless if you opt for 0.20", 0.025", or 0.031", you'd be able to use it (the extent would be up to your abilities). 


BTW, the larger the diameter, the less expensive it is as a general rule. FWIW, All-Spec sells Kester 44 in all diameters offered (pricing is competitive and shipping costs are reasonable as well). 

[JoeN]

I was just about to mention that.  All-Spec is pretty much the best place to get solder on the net.  Lots of choices, whatever you want.  Sometimes Amazon can be a bit cheaper on chemicals if you can get it to the $35 free shipping mark.  For a local place, Fry's has a lot of chemicals at about the same price as Amazon, and you can pick it up today if you happen to have one nearby.  I live close to the only one in Illinois so I consider myself lucky.

[Ian.M]

Mostly I use western branded rosin flux multicore 1mm (0.039") 60/40 or 63/37 Sn/Pb solder originally purchased on bulk reels.   I also keep small reels of 0.5mm (0.020") Sn/Pb and Sn/Ag/Cu and 1mm Sn/Ag/Cu for when 1mm is too coarse or I need to maintain ROHS compliance.   If its solely for your own use, starting from a bare board, Sn/Pb is somewhat easier to work with, but the moment you need to rework current lead free boards or are building anything for a third party, there is little choice but to bite the bullet and go lead free.   Big solder and small SMD parts needs a lot of practice to get nice joints without overheating the part or pads, but excessively fine solder gets really tedious for any larger joint, even if you twist up a yard or so into a thicker three strand wire.

[jitter]

Does rosin core solder really expire? I was thinking about getting a 1 lb roll of Kester 44 Rosin Core Solder 63/37 .020" but I'm worried it will expire long before I use it all up. The 3/4oz rolls are $10 each with shipping, so it's way more cost effective to buy the 1 lb (16oz) roll at $39.

I have a spool of Multicore solder lying around that's at least 10-15 years old and I don't notice anything out of the ordinary with it.
Solder pastes are a completely different matter, though. I don't use them at home, but at work, these are kept in fridges and a record is kept of when they are taken out to be brought up to room temperature before application.

[KL27x]

Regarding flux core and solder size, I think they're both moot, as far as SMD work is concerned. The flux is on the board and the solder is on the iron, if you're doing it the easy way.

I have soldered thousands of SMD IC's. I have reworked hundreds of tiny traces. I have repaired dozens of IC's down to SSOP on which a pin has broken clean off to the body. And I have never purchased solder thinner than 0.031." After suffering the angel hair stuff on a job site, I probably never will. I'm probably going to switch to 0.062", in fact.

[mikeselectricstuff]

It can oxidise on the surface over long periods of time, but usually only affects the outer layer on the reel, so unlikely to be an issue if used regularly.
Also seems to vary by alloy & brand - I have a box of random reels some 20-30 years old. Some are still very shiny, some really dull

[tggzzz]

Does rosin core solder really expire?

No. My 1985 solder is just fine for my use.

It may conceivably have changed sufficiently for a professional to notice, and still contains plenty of lead.

Solder paste is a different issue, although for amateur use the biggest problem is likely to be the solder precipitating from the resin - hence keep it cool and rotate it occasionally.

[6581]

Reading this thread, I'm now convinced I need to build myself a proper solder humidor. ;-)

More seriously, had never crossed my mind this might be an issue.

[SeanB]

I use solder which I bought as a child, and it still is usable. I have solder paste which is around 30 years old, but as it is 10% silver, has an acid based flux and is meant for stainless steel ( and works well for hard soldering copper pipe to stainless steel, though it is meant for stainless to stainless brazing) which still works after you stir a little.

[tggzzz]

Reading this thread, I'm now convinced I need to build myself a proper solder humidor. ;-)

More seriously, had never crossed my mind this might be an issue.

I don't think a humidor would solve anything!

More seriously, solder paste comes with an expiry date.

[DimitriP]

So...as far as "Does solder really expire?" 
is the short version of the answer "No, not really" ?

[Noise Floor]

Just piling on, but no don't believe so.  I have used solder that is at least 40 years old to no apparent ill effects. 
However using the old stuff I did find it did not flow as well as the newer stock I have, but that could have been my imagination.