CaiKleen RSF Rosin Soldering Flux, jar Rosin 56 g

flows very well, would definitely use this product again. Highly recommended

Excelente pasta para soldar. El unico detalle es que se debe controlar muy bien la temperatura para evitar que se queme la pasta (queda como plastico una vez que se quema). Yo la emplee para soldar cables de cobre chapados en plata con soldadura libre plomo y me funciono muy bien.

This solder doesn't seam to like lead free solder. I tried to solder with lead free and this flux barley works when heated properly. It creates black tarnish and carbon flakes. Doesn't remove anything, and make a layer of goo in which the solder won't make a bond with the copper because it repels it like hydrophobic materials. And I can't solder to aluminum or other conductive metals either. The only thing it is good at is cleaning my iron.

Had the Radio Shack branded version bought in the 90s and couldn't find it anymore when I lost it in a move. Tried many others for a few years but once I found the OG version searching one night, I gave them away. The smell, the stickiness, the accidental spill from leaving it on its side and not knowing, wondering how you got it on your desk, all of it was welcomed back once I got this. When you can't get solder to stick, use this and you will have no issues. It does require clean-up but for how well it performs it is worth it. I have ended up with some very professional solder joints. It is also the only flux I use when joining two stranded wires together with a fan and twist joint. It helps the solder to penetrate the joint quickly allowing you to control the solder pool so it's not larger than the wire sheath diameter.

Like this very much