F-SW26 no-clean flux?

[BlastFX]

I'm ordering new solder and I've noticed the datasheet for Stannol's HS10 which uses the F-SW26 (1.1.2) flux says it doesn't require cleaning.
I was under the impression that F-SW26 was a bit too corrosive to leave on a PCB. Am I wrong or is Stannol?

[dangerousamateur]

This topic may be old, but I have the same question.

Whats you opinion on this? I still have lots of F-SW26.
Should I prefer F-SW32 or 34?

[coromonadalix]

My comments would be :  whatever the flux type or brand 

Always do a board clean up

I've seen some corrosion,  residues who create problems in high frequency applications or sensitive high impedances circuits   .... it created some input leakages ....

I never let a board with flux on it, more than 4 hours

I've seen returned boards with corrosion under some parts  one year after assembly ...

my 2 cents

[dangerousamateur]

Thanks for the answer.

In fact I must say I don't make PCBs, I repair something sometimes... And I do a lot of RC modelling stuff.

I have a feeling that some very old F-SW26 / 1.1.2B I have works better with old parts that have been sitting in the cellar for a very long time.
But I never noticed any corrosion...

Is that whole corrosion issue maybe a thing that just becomes relevant when SMD parts are soldered with a wave machine and the flux can accumulate on the underside, where the flux is not properly cooked?
Maybe not even relevant in hand-jobs?