EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: PotatoBox on August 07, 2021, 09:01:36 pm
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Hello,
I've been used an old roll of Kester 44 solder and it has been working fine, giving nice and shiny joints, but I had just noticed that my flux pen that I use, a No Clean Flux, is different to the Kester 44's Rosin Activated Flux and I have been mixing the two. Is this an issue?
I was also given the advice that I should steer clear of Rosin Activated Flux and look for RMA or R type flux, as Rosin Activated is not suitable for stranded wires. Is this true? It's harder to find RMA or R type solder, as it seems that companies like MG Chemicals mostly offers only RA and No Clean solder and flux products.
Thanks,
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I’m pretty sure that countless millions of stranded wires have been tinned with Kester 44 solder wire. Maybe it’s not mil-spec, but it’s absolutely fine in normal use.
External flux is another matter: unlike the flux core inside solder wire, there’s no guarantee that external flux has reached the temperatures needed to neutralize it. This is at least as critical, if not more so, for no-clean than for rosin fluxes.
MG Chemicals carries only a basic selection of solders. A full-service brand like Kester has multiple products within each flux category. So if MG doesn’t have what you need, just look at a brand that does. :-//
As for mixing flux types: my own research into the composition of fluxes leads me to believe that no-clean fluxes don’t really use any novel fluxing agents or activators. They just have generally much lower solids contents and little or no rosin/resin contents. What they do use are ingredients also found in rosin fluxes. I strongly suspect that the primary reason behind the “don’t mix flux types” warnings is the fact that it’s an untested, unquantified thing, and thus does not ensure process reproducibility, so their lawyers said to say it so nobody can complain. I would not, however, mix water-soluble fluxes with any other kind.