Solder wire quality feedback

[acabre]

Hello exxos (and everyone here) !

Here is some feedback, about a batch of soldering wire rolls that I bought in the store two months ago.
I ordered these, as it's quite difficult to find good quality soldering material since lead was banned here in mainland Europe.
I was hoping you could still find some in the UK, but...

I used it last week, and I have the impression that it's just a bad Chinese product marked "63/37" which contains absolutely no Pb.
I still have some old 63/37 Sn-Pb wire (quite little) and also a leftover 60/40 for my workbench in the garage. My thermostatic station starts melting these two at 200°C, and they get really smooth and nice to solder when I set the temperature to 220-230°C..
I double-checked with a thermocouple and the melting point is around 190°C as the theory says (eutectic point is 183°C).

Now with this "Soldering Wire madeinchina 63/37 0.8mm", nothing really melts before pushing my station to 260°C and it's like plaster. I have to go almost to 320°C (setpoint) to obtain something more flexible and fluid, but I am about 100°C higher than expected !



[Update]
Eventually today before posting this, I tested all the tin coils at my disposal at home, some 99.3 Sn/Cu lead-free, others marked 60/40 or 63/37 of various qualities.

test-sn.jpg (252.41 KiB) Viewed 8971 times

I used a thermal camera, calibrated and double-checked with my thermocouple/meter on the tip of the soldering iron (IR cam measurement at 25cm, emissivity 0.55). I noticed that the set temperature of my soldering station must be set approximately 10% above the actual temperature measured and I noticed fluctuations of approximately 10°C on the regulation at times. That's quite normal and tells the tolerance for average values here after.

Here are my results:
- Some of my 63/37 rolls (Kaina CF10 models B/B-2) or 60/40 (Cynel Unipress, Rothenberger) melt well around 190-200°C as expected for Eutectic Sn/Pb (183/190°C). Their welding is fast, fluid and shiny.
- Sn99.3 lead-free rolls from suitable Chinese brands (Metal Products Co (Ali), Goobay (Amazon)) melt around 230°C with a nice appearance, which is consistent with the theoretical temperature (227°C). You have to raise the heat by around 50°C compared to the previous ones but their behavior is very correct, just less... coating / lubricant than with lead (useful for dry old solders).
- On the other hand, I have a "Jinhu 60/40 B-1" roll which gave a pasty appearance between approximately 220 and 260°C, then finally became fluid. This behavior is typical of a mixture far from a "pure" alloy. The appearance of the welds becomes dull as they cool.
- Finally, the tin coil purchased here (the white roll "63/37" #263) is the one that required the highest temperature : around 230°C it began to soften, but at 250 it still did not melt. It started to release a lot of smoke, then the wire disintegrated in small pieces around 260°C. I finally went up to 280°C to obtain real liquid fusion. At this temperature, soldering is feasible, it melts well, but gives off a lot of white smoke. The solder obtained is not completely dull but far from being as bright as the 63/37 or 60/40 tested previously.

You know that we retrocomputing enthusiasts should instead use lower temperatures during repairs, adding love, care and a few modern attentions to our patients.

These rolls of tin #269 (#263) therefore appears to be a counterfeit, in any case it is certainly not composed of Sn63Pb37 as indicated, but rather of a mixture of various metals and additives which give it a Solidus-Liquidus range almost 50°C wide (instead of a single melting point for the eutectic)

Ultimately this stock of soldering wire will be of no use to me, and will end up in my trash.
I'm not asking for a refund or anything, but I felt like I had to write this to you to avoid selling this inferior quality crap in your esteemed store in the future.

Thanks for reading.

[exxos]

Hello, Thanks for the report. The solder came direct from the manufacture. I just tested one roll and it does seem to leave a odd finish. It looks like half the joint is bright and smooth, but also looks like some of the solder hasn't melted properly. So I am not sure what's happened there. So I have contacted the manufacture about this problem. Meanwhile I am happy to refund the solder if you PM me your order number.

[exxos]

I've been battling away with this problem for the past few days, what a nightmare it turned out to be The sales rep has basically a several page rant from me about all these problems!

It turns out that the manufacturer list 63/37 as the solder "model number" but this isn't actually what is in the solder!! I was expecting it to be 63% tin and 37% lead. But this seems not the case. What it is actually, I believe it to be 25/75 , 25% tin 75% lead. Looking at their specification sheet it does actually specify 75% lead. So obviously I have been "conned", but not to a point of been outright lied to. But it comes pretty darn close!!

It also explains the somewhat "dull" finish because of the lack of tin content. It also explains why needs about 400c .

I found this chart online...

Capture.PNG (86.72 KiB) Viewed 8889 times

Basically the higher the lead content the higher the temperature needed.

I also found two other sellers on evil bay selling the same solder. Only they list it as leadfree. I presume they worked out it needed a really high temperature and further than assumed it was leadfree because of that. However it is not because it is leadfree, it is because it has a higher than normal lead content. The pictures show the 63/37 on the real also. That clearly isn't leadfree. But at least it is not just me that is getting duped in all this.

After further looking around the Internet, I soon found websites and videos about all sorts of counterfeit solder sold in China. Basically they are tricking you as to what the solder actually is, the majority don't even say what the composition is, but they do specify 63/37 but this could literally mean anything and not what you would ordinarily assume! So basically any solder from China you have to assume is counterfeit. I actually spent a lot of time hunting around for reputable looking manufacturers as well. It actually took some days! But even after that work, I still managed to get conned

So I think this mystery is solved.

I am in touch with my UK supplier for solder now. I know they manufacture it themselves and I've used them for years. So I have asked that a price for some 250g reels as I believe they don't sell smaller reels. But obviously its going to be the order of magnitude more expensive than buying from China. But then again, you basically get what you pay for with solder. You cannot go on what the Chinese specification is whatsoever, even if it looks genuine. It is also catching a lot of people out including myself

I even purchased three different reels of solder from evil bay which also claim 63/37, only one so far has turned up, and that clearly isn't what is specified either! I really don't imagine the other two reels will be any different.

Unfortunately it leaves me with a problem of what now to do with almost 1,000 reels of solder. While I could correctly write the specification in the store, I am not really happy about selling this solder. There is certainly nothing inherently wrong with it, but as the finish is a little bit substandard due to lack of tin content, and requiring a higher temperature than normal, I think people are going to struggle to use the solder, in particular if they are using a cheap soldering iron.

So I am not sure what to do. If anyone has any ideas.. Or anyone wants to bulk buy a lot of solder incredibly cheap...

[PhilC]

@exxos I'll buy my next lot off of you Chris, but it certainly won't be more than double digit quantity

[acabre]

You are right, I assumed that higher temperature meant less Pb (because of the 99% Sn rolls melting at 227°C), but I forgot my 30-years old lectures with the elegant phase diagrams for solid alloys :

snpb_phasediagram.png (518.94 KiB) Viewed 8836 times

If we visualize a vertical line at 25% Sn as you supposed, we find the conclusions of my measurements, with softening beginning at 200°C and complete melting from 260°C.
The correct method to know the composition (assuming that it is indeed a tin-lead mixture only) would be to precisely weigh a batch to determine its density. But we're not in physics class.


You are right too, regarding Chinese sources of supply, it is difficult to count on their quality and the markings are deceiptive, but sometimes you can be surprised in a good way. For this lot, however, the bet is lost.

I do not wish to return these rolls or be reimbursed, to show a sort of 'Atarian' solidarity. If you get your hands on some real quality soldering wire one of these days, though, I'd definitely reserve one or two!

[exxos]

Just for the sake of completeness. My lead testing swabs came today.

They start off as a yellow /orange colour which can still be seen towards the right. On the left it goes dark red which means lead is detected.

1.jpg (82.97 KiB) Viewed 8745 times

So for the people selling the same stuff on evil bay, it is not 63/37 and it is not leadfree like they claim either. It just needs a higher than normal temperature to melt it because of the high lead content.

I have actually been using this solder the past few days. Other than the high temperature requirement for melting it is good enough for most general stuff. So I will add it back into my store soon, but obviously quote the proper specification of it. I really need to get some new stickers made as not to confuse what is said on the current label in the future..

[rubber_jonnie]

Just for the sake of completeness. My lead testing swabs came today.

Interesting, does not feel like leaded to me, but there you go. Empirical evidence always works best.

[stephen_usher]

In my experience skimping on the quality of the solder is a false economy. The solder roll with last for a long time so paying a bit more is a tiny cost increase per use. That's why I always go for a good brand, such as Loctite. More expensive up front but far better in the long term.

[exxos]

In my experience skimping on the quality of the solder is a false economy. The solder roll with last for a long time so paying a bit more is a tiny cost increase per use. That's why I always go for a good brand, such as Loctite. More expensive up front but far better in the long term.

My previous reel of solder is Loctite . Though it is 1.2mm and I tend to use 0.7mm these days.

I should have some quality Uk-made 250g reels in the store in the near future. Looking at the prices in other outlets they are charging like £50 a roll now which is utter madness. I thought like £15 for 250g was expensive, but geese...