Solder Choices

[Doc B]

Looking at the spec for the Johnson solder it seems to have a nice low melting point. That can be an issue with some lead free solders.

Not that I would want to have any kind of hot solder near my Johnson.

 

[Strikkflypilot]

Thanks. So I guess it is easier to handle a low melting point with a soldering station where one can set the temperature, or else it would fast become too hot.

I will try it out on a small short wave Radio kit Ive got. As long as I make shiny solder joints, I guess Im ok.
And I will certainly think twice before I put the Johnson in the Mainline...

 

[Paul Birkeland]

It's more that the lead free solder will go on like toothpaste if you can't get it hot enough for long enough.  Most soldering irons won't get hot enough to be too hot for soldering.

 

[Strikkflypilot]

Will make a good testrun before I put it to any serious work, then

 

[Strikkflypilot]

Does anyone have experience with solder based on Kristall 400 Flux?
I ordered this Stannol Kristall 400 62(Sn)/36(Pb)/2(Ag).
It says the Flux is based on organic acids but thats probably what resin is all about and not a big problem as this solder seems to be made for electronics work.

 

[Strikkflypilot]

Let me try to answer my question myself.

Solderflux is mostly or completely inert at normal operating temperatures of electronic equipment but becomes active when heated to a certain level, where it becomes a reductant and removes oxidations. Rosin is solid resin and built up from, among other things, organic acids.(This is what concerned me) But as it is inert at operating temperatures of an amplifier it is not endangering the boards or components.

My conclusion: Kristall 400 seems to be a much more than adequate formula for soldering my upcoming Mainline, it seems to be very good, even, as it doesn't require cleaning up after soldering.

Now, please, tear these arguments apart if I am wrong.

 

[mcandmar]

I believe some solder goop can become conductive with age/heat.  Certainly with the Cardas Silver solder i have used it turns dark black with heat and looks fugly, hence i always scrub my boards with some IPA to remove any left over flux.

 

[Strikkflypilot]

Thanks for the reply mcandmar.
The Kristall 400 is supposed to be a no-clean flux, so I guess I will leave it and wash away with isopropylalcohol in case it does get dull looking?

 

[mcandmar]

No clean should be fine, but i would clean it anyway just to make it pretty   There are, or there were flux types that were corrosive and would eat away at PCB traces, but those types are probably extinct by now.

 

[Strikkflypilot]

Do You use IPA on all solder joints, or just boards?