I do Christmas lights on a grand scale and do a lot of soldering of wire to wire, wires to circuit boards and printed light tracks and I have always used a home made flux (secret recipe) that has been given to me by our IT guy at work. It works well, but is a bit thick and smokes a lot. I have not seen a wire join to a track that quickly. I love the fact that your flux is brushed on so lightly like water and works so well. What concentration is your Phosphoric acid mix for these projects?
Great tutorial! I was getting so frustrated with soldering until I saw this video. Now my soldering is going swimmingly. One question: I've heard people warn against using acid flux due to the fact that it has the potential to cause corrosion over the subsequent months/years. Have you had any issues with corrosion? In my experience, it seems to all boil off nicely once I apply the solder. Now I've found a method that works for me I'd be hesitant to change it again. Many thanks. Matt.
Hello Matt, thanks for your comment. Fluxes by their nature are corrosive and when heated dissipate well. I have used 6% Flux for donkeys years and haven’t had any breakages with multi-strand wire or indeed with one core wires (even down to 28AWG copper Kynar). It can be a problem if not addressed properly and to do that only a ‘wipe’ is required, not ‘flooding’ of flux on the wire. For repetitive cable work, LED soldering to brass etc for the lights I make, I also keep a paint brush in water and wipe away (or rinse) any residue. It generally evaporates quickly with the joint still being warm. The old saying “cleanliness is next to Godliness” is very applicable here so it’s always important to keep everything clean and dry. Paper towel rolls are a big feature in many aspects, whether it’s for drying off excess flux/water or for mopping up after a spill!! Take care, and thanks again for your comment.
Very helpful for a complete beginner like me. My question is, when you come to the last stage of applying heat to the tinned wire and the soldered track...is there any solder on the iron, or just a hot iron? Thanks for any assistance.
Hi, thanks for the message. In short, no. A small trace of the same solder on the iron is usually enough to flood the solder into the joint. In relation to Fluxes, I use here a 6% phosphoric acid flux but many don’t like this as it can eat into wires over time. The favourite expression is that it creeps up the wire by capillary action and sits there nibbling away. There are, of course, other fluxes available which are non corrosive (check data sheets when ordering). Flux dispensers are a handy tool, whether pen-like or in small bottles. My fluxes come from Wizard Models in NE Lincolnshire. Having said all this I haven’t had any issues at all.
I favour that from “Wizard Models”. It is the 6%. I have also used that supplied by “London Road” “Frys” flux for plumbing is also very good. It’s a paste and only requires a minimal amount so can last a long time.
