[sdiy] top soldering through hole

[MTG]

Hi all you no clean flux people (again, sorry to drag this conversation 
out), I still find the residue a bit cosmetically unpleasing with 245. 
Especially after a few weeks or months it seems to go a bit white-ish. 
Possibly I'm using too much, or the core is too big?  Here is the last 
one I bought:

https://www.mouser.com/ProductDetail/533-24-6337-8802

This is a 63/37 with a core size of 66.  Should I consider a smaller 
core size such as 58 like this??

https://www.mouser.com/ProductDetail/533-24-6337-8801







On 2/14/2018 11:19 AM, Roman wrote:
> No-clean flux is called that way for a reason. You can leave it forever. 
> That was made especially for cables, where it's not really possible to 
> wash it well, as well service and DIY.
> Water soluble must be washed immediately, because it's so active it will 
> cause corrosion. Mostly used in mass production, as it can easily be 
> washed with water, no nasty chemicals needed. That means cheaper.
> Cleaning PCB only so-so is worse than leaving no-clean flux intact. It 
> opens all the nasty stuff from rosin and spreads that all over the 
> board. Together with humidity, dust and electricity it can do harm.
> I take cleaning my boards seriously, so it's a couple stages process. 
> But that's just me.
> 
> The cleaning boards topic comes out recenlty every few weeks on every 
> forum I'm in. Is it somehow driven by PCB cleaning suppliers?
> 
> Roman
>