I'm bumping this thread because I'm in the exact same boat as the op. Wondering if anyone has experience comparing Kester 44 with 245 and 275 (and maybe 285) in practice?
I currently use Kester 44 in 63sn/37pb, which I like. But I agree with the op, the flux is hard to clean and I usually just leave it. I intend to stay with 63/37, and I'm curious if the other flux formulations are improvements over 44 or just different? Specifically regarding amount of residue left after soldering, cleanability, and ease of hand-soldering.
Ive been using the 245 for a few years now. Its eutectic, not 60/40. (At least the stuff I have is)
The no-clean core does leave behind this sticky flux residue but it does clean up easily with isopropyl alcohol and cleans up far easier than anything else I've used though I've not used that organic fluxed solder.
Kester 275 is no clean and doesn't leave a lot of visible residue.
Have either of you compared the 245 or 275 to the 44?
I ordered some Kester 245...maybe it will be a bit better.
I was trying to decide between 245 and 275. I couldn't really find much difference but I've never looked into solder much. I've just been using 44 since it works really well for repair.
What made you lean 245? Or did you end up staying with the 44?