Cheap solder leaving strange residue?

[Jay112]

A roll of lead solder I recently bought from ebay seems to be having some strange problems that I've never seen into before with other solders. Every once in a while when I'm soldering there will be a strange plastic-like string that hands down from the tip of the solder, almost like as if there was a thin line of burnt plastic inside the solder. I feel pretty certain that it's not because I'm accidentally burning any nearby plastic pieces.

Have you ever seen anything like this? Do you know what it's from?

[Fsck]

is it some unknown brand that substituted something in for flux?

[Jay112]

I don't know enough about solder to know which are the popular brands.

This was the title of the solder: "A roll of 0.5mm 100g Tin Lead Rosin Core Solder Soldering Wire"

And this is the ebay link:
http://www.ebay.com/itm/A-roll-of-0-5mm-100g-Tin-Lead-Rosin-Core-Solder-Soldering-Wire-/172180016673

[Cubdriver]

Some sort of contamination in the rosin core would be my guess.  Does the smell of the rosin smoke change at all when you get this plastic-y thread?

-Pat

[Fsck]

well, the rosin core flux is a solid and will be plasticy when melted.

is it actually like burnt plastic? (charred, smokey, etc?) or just melted plastic?

[rstofer]

Buy some decent solder:

http://www.specialized.net/Specialized/Multicore-MM00992-Solder-Sn60Pb40-02522AWG-RosinFlux-5Core-683.aspx

http://www.alliedelec.com/kester-solder-24-6040-0061/70177924/?utm_source=bing&utm_medium=cpc&utm_campaign=Product%20Ads&mkwid=6kTPp5T7&pcrid={creative}

I try to buy the Multicore when I can but it takes about 15 years to use up a roll.  I just don't tend to do a lot of hand soldering.

Considering all the time and effort that goes into designing circuits and PCBs plus the cost of the PCBs and components, cheap solder is a really bad idea.

There will be rosin left on the board even with the best of solders.  I don't tend to remove it but you can if you wish.

[Jay112]

Thanks for the replies, everyone!

I think it's more like melted plastic than burnt plastic, and I don't think it smells like burnt plastic. It doesn't create any smoke either.

A unique thing with this solder is that it's the thinnest solder I've ever used. Do you think maybe that's related?

@rstofer: Thanks for the links! That's great advice about not going cheap with the solder.

[Fsck]

thin solder will probably have a higher flux:solder ratio, so maybe.

if it's amberish in colour, it'll probably just be the rosin flux residue (normal). I use kester 44 and just leave it on there. I prefer the 63/37 eutectic over 60/40 though.

I think I'd probably clean an unknown brand's rosin flux residue though.

[Jay112]

thin solder will probably have a higher flux:solder ratio, so maybe.

if it's amberish in colour, it'll probably just be the rosin flux residue (normal). I use kester 44 and just leave it on there. I prefer the 63/37 eutectic over 60/40 though.

I think I'd probably clean an unknown brand's rosin flux residue though.

Thanks for the advice.

If I coat a board with conformal coating, do you think that prevents the damage from the flux? Or should the board be cleaned before applying the coating?

[KL27x]

I get rosin strings a lot when using external RA. I've never seen a flux core solder have that high a flux content, but this is a good thing.

The residue is usually completely harmless to the electronics. But if you are going to do a conformal coat, remove the residue, first! Alcohol works fine. A mix of 91-95% alcohol + acetone is really effective.

[Bud]

"High quality Best made in China"

Yes, this instills a lot of confidence.

[Audioguru]

"High quality Best made in China"

Yes, this instills a lot of confidence.

They cannot put their sewage (there is lots of it) in the ocean because they drink the sea water so they ship it in the solder they export. I bought some cheap Chinese stripboards that used sewage to poorly and loosely stick the copper to the phenolic. I think the phenolic was made of used toilet paper. https://www.eevblog.com/forum/Smileys/default/rolleyes.gif

[Jay112]

"High quality Best made in China"

Yes, this instills a lot of confidence.

They cannot put their sewage (there is lots of it) in the ocean because they drink the sea water so they ship it in the solder they export. I bought some cheap Chinese stripboards that used sewage to poorly and loosely stick the copper to the phenolic. I think the phenolic was made of used toilet paper. https://www.eevblog.com/forum/Smileys/default/rolleyes.gif

I actually did receive 100% garbage from ebay once. They sent me a package that contained an empty toy bag. Has that ever happened to you guys? It seemed strange to me, because I had ordered 4 items from that seller, and he had shipped out 2 of them, but then I received the empty bag instead of receiving the other 2.

The strange thing is that if he was trying to scam me, I would've expected the entire order to be a scam. Why would he only ship half of it?

I think that was the 2nd time I was scammed on ebay (I've only started using it about 6 months ago, probably placed a few dozen orders since then). For the first scam I ordered "100% solid copper" wire, only to receive copper-clad steel. There's a thread on this forum where you guys helped me with that.

[nanofrog]

FWIW, there was is such a thing as plastic core solder (type R)*.

As previously mentioned, definitely spend a little extra for quality supplies (solder, flux, desolder wick), as it's actually cheaper in the end.

Not only does it cause less damage to boards, you get better results (better flow, & reduced time on joints). And then there's the reduced aggravation as a free bonus.   


* I found a sheet on it (here). Still available by special order it seems (Kester P/N = 24-6040-1809, which is 60/40, .031", 58 core size ).

[Jay112]

FWIW, there was is such a thing as plastic core solder (type R)*.

As previously mentioned, definitely spend a little extra for quality supplies (solder, flux, desolder wick), as it's actually cheaper in the end.

Not only does it cause less damage to boards, you get better results (better flow, & reduced time on joints). And then there's the reduced aggravation as a free bonus.   


* I found a sheet on it (here). Still available by special order it seems (Kester P/N = 24-6040-1809, which is 60/40, .031", 58 core size ).

Interesting. Do you know why anyone would need plastic core solder? The only thing I could think of was maybe the plastic has a high melting point, giving the solder the ability to be melted into various shapes?

[nanofrog]

Interesting. Do you know why anyone would need plastic core solder? The only thing I could think of was maybe the plastic has a high melting point, giving the solder the ability to be melted into various shapes?

Off-hand, I can't think of anything that would require plastic R vs. R liquid or paste that's ROL0 compliant, but suspect it's for some rather particular MilSpec application (something to do with fungal growth?). 

As per casting, you typically use bars or slips, not solder wire.

[Fsck]

thin solder will probably have a higher flux:solder ratio, so maybe.

if it's amberish in colour, it'll probably just be the rosin flux residue (normal). I use kester 44 and just leave it on there. I prefer the 63/37 eutectic over 60/40 though.

I think I'd probably clean an unknown brand's rosin flux residue though.

Thanks for the advice.

If I coat a board with conformal coating, do you think that prevents the damage from the flux? Or should the board be cleaned before applying the coating?

always clean first.

[macboy]

FWIW, there was is such a thing as plastic core solder (type R)*.

As previously mentioned, definitely spend a little extra for quality supplies (solder, flux, desolder wick), as it's actually cheaper in the end.

Not only does it cause less damage to boards, you get better results (better flow, & reduced time on joints). And then there's the reduced aggravation as a free bonus.   


* I found a sheet on it (here). Still available by special order it seems (Kester P/N = 24-6040-1809, which is 60/40, .031", 58 core size ).

It's a bit of a misnomer, as there is no "plastic" (i.e. synthetic polymers) present. It is a pure, non-activated rosin core. This is a rather special product only used where the activating agents normally added to the rosin can't be used. Kester "285" is their RMA (Rosin, Mildly Activated) and "44" is their RA (Rosin, Activated). I really like soldering with Kester 44, but I also have some 285 and it is also nice since the residues are water clear rather than amber colored.

[nanofrog]

It's a bit of a misnomer, as there is no "plastic" (i.e. synthetic polymers) present. It is a pure, non-activated rosin core. This is a rather special product only used where the activating agents normally added to the rosin can't be used. Kester "285" is their RMA (Rosin, Mildly Activated) and "44" is their RA (Rosin, Activated). I really like soldering with Kester 44, but I also have some 285 and it is also nice since the residues are water clear rather than amber colored.

I'd seen it in person, but never used it (did know it was R at least). I took the use of the word plastic literally however, as I don't recall any other roll of R from other manufacturers using the term.   

FWIW, I keep 44 on my personal bench (familiar with 285 & 48 too), as well as 186 and 1544 liquid flux. Some other stuff too (Multicore, Alpha Metals, and even some ancient RadioShack). And Chemtronics for wick.   

Learned the value of good quality consumables a long time ago (had the fortune of some excellent mentors when I was a kid). 

[Cubdriver]

Kester 44 63/37 is my main go to as well.  I also have a spool of the 331 organic core that gets used on PC boards that can have a bath immediately after assembly, but (as I learned the hard way at a previous job when someone DIDN'T give the boards a bath after soldering them), it's hygroscopic and corrosive if not cleaned off.  There's also a spool of the silver bearing Kester floating around here somewhere, but I haven't had occasion to use that yet.

My inclination with things like solder is the use the good stuff.  It's not that much more $$, and this is definitely one place where crap can cause you no end of headaches between making assembly needlessly difficult, causing overheating of components trying to get them to wet and later potentially causing troubleshooting misery due to bad joints.

-Pat

[sleemanj]

FWIW, my main roll of solder at the moment is BEST 0.4mm, and it pretty much lives up to it's name of the various Chinese solders I've used over the years, goes on well, good flux content, produces a good looking joint.  No complaints. 

I did once have a roll of "San He" 0.6mm which wasn't half bad either.

I didn't particularly like the Synhonty 0.6 from eBay, and the PPDESD 0.3mm also from eBay was a bit iffy on the flux consistency (probably to be expected at 0.3mm)

But of course, like anything from China, just because I got a good roll of BEST today, doesn't mean that you will tomorrow. 

[RobertHolcombe]

Some cheap generic brand solder I've used came with an adhesive sticker attached to the roll, contacting the first layer of solder - every ~100mm or so there would be a small amount of adhesive residue on the outside of the solder, and produced what OP describes

[Jay112]

Some cheap generic brand solder I've used came with an adhesive sticker attached to the roll, contacting the first layer of solder - every ~100mm or so there would be a small amount of adhesive residue on the outside of the solder, and produced what OP describes

Wow! This definitely might be it! There was a sticker that seemed to leave some residue on the outside of the roll!

I guess the way to tell if this was the case is if the residue stops appearing once I get past the first layers. But if it continues appearing through the rest of the roll, then I'll just assume it was either the flux or some other cheap thing they put in there.

[sleemanj]

I guess the way to tell if this was the case is if the residue stops appearing once I get past the first layers. But if it continues appearing through the rest of the roll, then I'll just assume it was either the flux or some other cheap thing they put in there.

I guess this is a good reason for the avionics solder-ers wiping down the solder before they use it :-)

https://youtu.be/Vynb_HdEIDU?t=7m4s

Of course, I'm hoping they aren't sending satellites to space with eBay chinese solder :-)

[RobertHolcombe]

Unless the reel is coming sealed from the manufacturer you never know what has been in contact with the outer layer so would be good practice to at least clean the outer layer with IPA when you buy it, only takes 5 seconds