Popping Solder - Page 1
Forum section: electronics / general

author: vidarr
author_rank: Frequent Contributor
timestamp: May 09, 2025, 03:46:27 pm
content: This batch of solder I got has a weird problem, it pops, like mini-explosions and sends small balls of solder shooting out. It looks like a miniature, white phosphorus attack. It pops, shoots out the smoking particles, they land and burn everything they land on and it leaves white trails in the air and smoldering and white smoke coming out from everywhere they land.This is the first time I ever saw anything like this. Nothing in my gear has changed, except the solder.It is really bizarre. Also, I can't use it. Now, I have all this solder that is useless. (I cannot return it.)V

author: Simmed
author_rank: Frequent Contributor
timestamp: May 09, 2025, 03:55:24 pm
content: you need to tell us the brand/model

author: jnk0le
author_rank: Regular Contributor
timestamp: May 09, 2025, 04:22:56 pm
content: That stuff should be flux. (moisture?)It should pop less at lower temperature.

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: May 09, 2025, 04:23:17 pm
content: Something is wrong with the flux. Perhaps it's contaminated with water.

author: Ian.M
author_rank: Super Contributor
timestamp: May 09, 2025, 04:45:09 pm
content: You can also get popping from single layer PCBs with too high a moisture (or other volatiles) content. This is more common with SRBP (phenolic) PCBs vs FR4 ones.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 09, 2025, 05:36:19 pm
content: I've seen something similar, with a lot of popping and splashing, when I've tried to use solder paste destined to household installations. There is soldering alloy and soldering paste made to weld together copper pipes and fittings, like the pipes used for heating and water indoors installations. That kind of alloys was made to be used with an open flame torch, and when on pipes, used with a torch, it doesn't splash like when it is used with a soldering iron on PCB.My attempt was to use much cheaper solder paste for pipes, in older to cover all PCB traces with solder. Didn't work.

author: vidarr
author_rank: Frequent Contributor
timestamp: May 09, 2025, 06:11:06 pm
content: They sell this solder at the hardware stores and also the electronics stores. So, could be it is for plumbing. I don't know why they would sell it at the electronic stores though.

author: vidarr
author_rank: Frequent Contributor
timestamp: May 09, 2025, 06:15:35 pm
content: Quote from: jnk0le on May 09, 2025, 04:22:56 pmIt could be what you said, because right now, it is pretty hot and the humidity is very high. We are starting the raining season here (Salvador, Bahia, Brazil).I'm trying to remember if this happened last year around this time. I think it might have.All I know is it sucks bad. It looks cool, but it is going to ruin something if I am not careful.

author: TimFox
author_rank: Super Contributor
timestamp: May 09, 2025, 07:28:18 pm
content: Quote from: vidarr on May 09, 2025, 06:11:06 pmResin/rosin flux is normal for electrical soldering, and does not require removal after soldering.I believe plumbing is usually soldered with an “acid” flux that is later removed by rinsing with hot water.

author: jnk0le
author_rank: Regular Contributor
timestamp: May 09, 2025, 10:07:35 pm
content: Quote from: vidarr on May 09, 2025, 06:15:35 pmI think the moisture had to be trapped during manufacturing. Metals are not good at passing moisture.Had the same thing on 1+mm solder wire. Going above 300*C resulted in the larger splashes. Currently 0.56mm of the same brand - no issues.

author: vidarr
author_rank: Frequent Contributor
timestamp: May 09, 2025, 10:50:41 pm
content: Quote from: jnk0le on May 09, 2025, 10:07:35 pmYeah, that makes more sense. The solder is made in Brazil, so it is very likely the solder is very low quality.It finally popped and landed on my finger. Useless solder. Good thing I bought a bunch of solder last time I was in the USA. Time to switch over.Thanks Guys!

author: Analog Kid
author_rank: Super Contributor
timestamp: May 09, 2025, 11:17:58 pm
content: Quote from: TimFox on May 09, 2025, 07:28:18 pmTrue.If one had to, one could use plumbing solder for electronics. (Not recommended!) But you'd have to make damn sure to wash away all the flux, otherwise you'll be looking at major corrosion.I use plumbing flux (non-acid paste) to clean my soldering iron tips, making sure to wipe away all the flux before electronic soldering.