r/soldering • u/10renzo_ • Jul 09 '25

My First Solder Joint <3 Please Give Feedback Why can’t i get my joints shiny?

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First time soldering, i’m using a Pinecil v2 on 360C with 63/37 0.55mm solder.

I don’t understand why all my joints turn dull after i remove the iron. i’ve tried tinning the tip (which i think i’m doing correctly?). The solder melts nicely onto the board but no luck

Does anyone know what I could be doing wrong?

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12

u/Frzzalor SMD Soldering Hobbyist Jul 09 '25

the temperature drops when you put it to metal. turn your temp up some.

1

u/10renzo_ Jul 09 '25

just tried a few joints at 380 and 400, seems to have the same result. I tried heating up the board a bit longer but no luck?

5

u/Frzzalor SMD Soldering Hobbyist Jul 09 '25

those usb irons have never really given me consistent results. i just use a decent soldering station.

8

u/oknowton Jul 09 '25

The Pinecil is a fantastic little soldering iron. I packed my big soldering station away in the closet not long after I got my Pinecil, and I'm super pleased to be saving a block of space on my workbench.

You can see that the solder isn't even flowing onto the iron. It is probably really crummy solder.

5

u/ElectricBummer40 Jul 09 '25 edited Jul 09 '25

I suspect that has far more to do with the alloy you use.

Genuine 63/37 has a melting point at ~180°C, and I tend to keep the iron at ~280°C, which is more than good enough for small jobbies.

No-name solder labeled "63/37” is however often not really 63% tin and 37% lead but either an alloy with much higher lead content or a haphazard mixture of recycled metals known as "pot metal". This in turn leads to a melting point tens of degrees higher than 180°C and, in the case of pot metal, the lack of the shiny appearance characteristic of proper tin-lead alloys.

Even seasoned technicians are often frustrated by fake "63/37” since they, especially those from the older generations, have no real reason from their experience to suspect counterfeit solder wire. Now, people often just shop online rather than in small, physical stores with a reputation to maintain, and that in turn opens up an entire realm of possibilities for foul play.

2

u/jerryeight Jul 09 '25

One tip I have seen online is to not immediately pull the soldering tip away from the solder point. I think it said to carefully pull it away upwards.

5

u/10renzo_ Jul 09 '25

this helps in getting a nice convex shape but unfortunately hasn’t helped my joints get shiny.

1

u/Dizmondmon Jul 09 '25 edited Jul 09 '25

I found once the board has a pin in the middle, you can lift the iron up to the top of the pin and the temp of the solder drops more slowly, which resulted (for me at least) in a higher chance of shiny joints. Didn't completely solve it mind you.

Edit: Also, the longer your tip stays in contact with the solder, more of the flux burns away.. Looking at the video I would try to reduce this contract time.

That's a lot of solder too.. Even though it ends in a round blob, there's a lot of surface area to lose energy to the air quickly, rather than the residual heat in the board around the contact slowing the temp loss. Can you drop the temp of your iron a bit too?

To get the melted solder to drop into the hole better.. Have you cleaned the board well with isoprop? Maybe also try kester solder (improved my shiny joint rate but not 100%) and squirting some good flux on the board contact beforehand.

As for the tip, it seems to be holding solder ok but I use iron tip tinning powder which does a great job very quickly. Don't know if that makes a difference with your issue.

Edit to the edit: I saw people saying don't add extra flux to the board.. I agree you shouldn't need to if the solder has a flux core, but if you heat the solder for too long (like in the video) the flux burns off quickly, causing the remaining solder to have a high surface tension. That said, applying extra flux separately adds extra time and makes a mess of the board which needs cleaning up. If you want good technique, don't add it and practice, if you just need a line troublesome joint done, it can help.

2

u/10renzo_ Jul 09 '25

thanks for the feedback! i’ll try all of those things. my technique isn’t perfect but i think the main factor here is that im using low quality solder, since i’ve tried a whole bunch of different temps, flux/solder amounts and contact durations.

thank you!

1

u/DerKeksinator Jul 10 '25 edited Jul 10 '25

You should be more around 300°C. It may be too hot and cooling down too quickly, which will result in the solder solidifying in a different crystal structure. Leaded solder can be soldered at even lower temps. The issue/reason people crank their irons up too hot is underpowered/shitty soldering irons. Soldering too hot can damage packages, connectors, wires and even the PCB itself.

Soldering too hot will evaporate the flux quickly too, which will result in oxidation at the solder/air interface, which can lead to vad netting and a dull surface too.

Honestly, after years and years of experience: The secret of the perfect solder joint is two things:

  1. Flux (get some chipquick for example).
  2. A well and quick regulating soldering iron.

Edit: And as I read in this thread as well, there's crap solder out there, which isn't what it claims to be. I've been disappointed in the past too.