this is a specific question to a product for soldering.

I am a newbie to soldering so be kind. To be honest I was trying to learn soldering and watched videos and read some. But in germany there seems to be an unwritten law to make finding the right soldering stuff as hard as possible (also confusing) It is called soldering paste which someone else in IRC thought is something else but after he showed me what soldering paste is , some grey material for stencil , I can assure you it is not. This stuff is orange like flux should be I guess.

So I got me some tools and materials and one of them is these:


If you go to the download sections you can see Datasheets. Edit : It says "Activated resin mixture with petrolatum"

Now my question is can I use this on electronics? I want to solder on PCB, some pins to a microsd adapter for example.

This material is orange and I did not test it yet.

Here is a pic of it: Some of the products for soldering I bought

  1. Also if you can tell me if that soldering tin (Sn60Pb39Cu1 with flux) is good (for my purposes)? You can search on Conrad.com for it just enter this in search : 812803 I can not post anymore links thx to this restriction..

tl dr : Is this good flux for electronics soldering? Is this soldering tin good for electronics soldering? Also if any tips, tell me.

Thanks for your read :)

  • \$\begingroup\$ Tip: Solder fumes aren't healthy, especially those from tin including lead (Pb), as yours. Solder in a well ventilated room, preferably with a fan sucking the fumes away from you. \$\endgroup\$ – Grebu Jul 8 '17 at 12:46
  • \$\begingroup\$ Thanks I will do it outside with a fan blowing it away :) \$\endgroup\$ – Yun Zhao Jul 8 '17 at 12:54

Both will work. In this particular case, the paste is actually essentially the same flux as the wire provides, so there is no penalty (other than a very high inconvenience level) in using it.

In general, though, solder pastes are acid-based, and much more aggressive than rosin-based. You can use such fluxes, but intense care in washing off the residue is required to avoid corrosion later. So be very careful about using any paste flux. Plus, of course, you wind up using a lot more flux when you use paste, since you have to spread it over the area to be soldered. Flux-cored solder provides the flux at exactly the point it's needed.

  • \$\begingroup\$ Okay so , using the paste makes it easier I guess? Also you say acid-based? How do you know it is acid based? I don't see anything stating it is acid based. If all paste fluxes are acid based, what should I then use? Or should I just stick to cleaning it off. If cleaning what other than alcohol can I use to clean it? \$\endgroup\$ – Yun Zhao Jul 8 '17 at 12:55
  • \$\begingroup\$ @YunZhao - "using the paste makes it easier I guess?" Nope. You get flux all over the place and cleanup is a big job. "How do you know it is acid based?" It's not acid-based. Please reread. Most readily-available paste fluxes are, but not this particular sort. And I know this because I used the internet to find the flux you show. "If all paste fluxes are acid based, what should I then use?" They are not. But most are. And you find out which is which by looking up the product details. "If all paste fluxes are acid based, what should I then use?" Water. Lots of water. \$\endgroup\$ – WhatRoughBeast Jul 8 '17 at 13:46
  • \$\begingroup\$ @YunZhao: the fluxes used by plumbers with copper pipes is generally acid-based. Any flux sold for electronic work will be non-acid. \$\endgroup\$ – Peter Bennett Jul 8 '17 at 16:11
  • \$\begingroup\$ Rosin flux is acidic when it's actually accomplishing something, but quite mildly so compared to a plumbing flux like zinc chloride. \$\endgroup\$ – Chris Stratton Jul 8 '17 at 18:42
  • \$\begingroup\$ I hope it turns out good. \$\endgroup\$ – Yun Zhao Jul 10 '17 at 18:40

You just need the solder with the flux core. You don't need the flux paste.

The flux paste is essential when "drag-soldering" fine-pitch devices, because the blob of solder on the iron tip no longer contains any flux.

  • \$\begingroup\$ Oh I see. I thought the flux in the wires may not be enough. \$\endgroup\$ – Yun Zhao Jul 8 '17 at 12:54
  • 1
    \$\begingroup\$ I've always found it sufficient. The paste is intended for use with solder which does not contain flux. \$\endgroup\$ – Leon Heller Jul 8 '17 at 13:12
  • \$\begingroup\$ Add-on flux is more typically needed with lead free solders, especially when the parts, pads, or wires have even the slightest tarnish. Leaded solders will usually work on moderately clean surfaces with just the rosin core flux. \$\endgroup\$ – Chris Stratton Jul 8 '17 at 18:40
  • \$\begingroup\$ I will try to use a little paste some time to see the difference. If it helps I will use it more often then, the only concern for me was if this really is not acid based, because I did not know how to make out if it is acid based , or rather if it can be used on electronics safely. \$\endgroup\$ – Yun Zhao Jul 10 '17 at 18:37

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