Solder Paste Flux vs Rosin Flux for Electronics: ICs, Resistors, Transistors - Cynel-1 Usage

Hello
I have a problem with the selection of flux. Whether to use plain rosin or solder paste flux (no tin powder). I mean simple soldering of electronics (integrated circuits, resistors, transistors), not SMD and not BGA. I heard that the toothpaste is better at washing off, but it conducts electricity and is (a bit) corrosive. The rosin is good, but it's worse to wash it off and it sticks (which I don't like). I have Cynel-1 solder paste, but from what I read on the electrode, it probably is not suitable for electronics, and what is your opinion about this paste? Suitable for electronics (not SMD and BGA)?
Therefore, I am asking you for your opinion on pastes and examples of good solder paste for electronics , not for pipes, cables, lugs etc.

greetings

I think rosin can be removed with alcohol or turpentine. I use rosin out of habit ... and mostly because I've had quite a lot of it.

The rosin can be removed with alcohol, but the more dried it is, the worse it is to remove.
From what I saw on Cynel-1 paste, it does not dry out after soldering, it remains liquid and looks like water.
I am waiting for the opinions of someone more experienced in soldering pastes in electronics.

I did not use Cynel-1, but in fact you do not need a flux for regular soldering, the one contained in the tin is enough, you only need to regularly wipe the tip with a damp sponge and do not solder by scooping the tin on the tip and applying, only applying it immediately tin to the soldered place. Once I remember you could actually get liquid fluxes in glass vials, which were a bit caustic, but now I don't think they do. If you still need a flux (I use it sometimes for SMD, cables, it is good for plugs, e.g. mini-jack when you need to remove oxides because you cannot solder without this cable, if you need to remove the tin from the ends of the elements, and for disassembly, of course) then I can recommend you AG Chemia soldering paste, it costs nothing, it's such a thick brown goo, you scoop it up with a small screwdriver, heat it with a soldering iron by dropping a drop into the soldered place, the paste dissolves under the influence of heat and thickens again, the residues are very easily removed - with a screwdriver, then rinse with a cotton swab soaked in isopropanol (be careful not to leave any lint, sometimes I also wash it with a brush) and there is no trace. Even if you do not remove it, nothing will happen because it does not conduct electricity (unless there are some high voltages, I do not know) but this paste is sticky (not like rosin dissolved in the spiral, but a bit sticky) so better to wash .

I recommend visiting http://www.cynel.com.pl/pl_r_topniki.php
It seems that this paste is suitable, but you have to be careful with solder pastes and always check what they are for and what they are based on, because some of them contain hydrochloric acid and are suitable for soldering galvanized sheets, but in no case electrical connections that corrode very quickly after Soldering the board with such a paste would be nice but then it would turn out that there are short circuits by the paste (if unwashed) and then green and broken paths even when the paste is washed off.

The description of AG chemistry solder paste is very similar to the description of Cynel-1 paste. Only there (AG chemistry) says "... is used where rosin is not enough", which means it is probably stronger (maybe corrosive) than rosin. However, in the description of rosin, he writes "... has an activity similar to solder paste." So there is probably no big difference with them?

PS. I know that you don't need to solder "fresh" paste / rosin chips, but sometimes you also need to replace something there. It is also useful when you need to tin a new plate (homemade).

To tin-plate a raw plate, it is enough to clean it well (water-based paper) and instead of a rosin solution, use a solder based on acrylic based solder. like rosin and hard to carbonize. Also good for securing the tile after assembly.

Hello.
I am a staunch opponent of the use of solder paste in precision electronics, I know it from practice and I struggled with it, because some colleagues used it for easier and faster PCB soldering, but the effects were sometimes even tragic even with nap. Several tens of volts. You can solder the cable lugs with paste, and even then wipe them well because they melt. Just insert the two ends of the ohmmeter / M? range / and see for yourself.
Greetings co