Solder Choices

[Grainger49]

Ok, I'll throw in. To start with you are heating up a terminal or tube pin AND a component lead.  You want these two to be hot so the pool of solder flows onto both.  Once you see this you know what I'm saying.

I "tin" the tip with just a small amount of solder, apply the iron with the liquid solder on it so it heats both pieces of metal (terminal, pin, component lead) and wait a few seconds for the cold metal to heat.  Then I put some solder on anything but the iron tip and see if the solder flows.  I add enough to cover both pieces, not necessarily closing the hole in the terminal/tube pin, then remove the iron.

Then I clean the soldering iron tip and place it in the spring holder.  I clean the tip after every joint!

And to add to Dan's comment, be careful not to lay the iron on other components!  It can ruin some of them.

[Schroeder77]

Thank you for your advice. In fact, immediately after posting today's question I set up my newly purchased iron and took out the board and wire I bought to practice this week before I receive the Crack. So as of now I've got some practice in and I'm looking forward to more tomorrow.

Last time I soldered was for a theremin kit 15 years ago, and when it didn't work, I brought it to an electronics person who fixed "more than several" cold solder joints. I tried to look for them before bringing it to him, but I just didn't see it. I have better equipment now, more than enough theory from videos, I guess I'm just paranoid about my skills.

The soldering skill is the only critical component you don't provide in your box (ok and the ability to use a meter to check work), I'm just a bit obsessive about making sure it's there and waiting the day of delivery. Kind of like preparing the baby's bedroom. :-)

Thank you so much again everybody!

Duane

[airdronian]

My suggestion is stop reading and start soldering. It's an eye-hand coordination skill that you have to master by repetition. As you solder more you will develop a feel for the thermodynamics involved and when you need to pre-tin, reflow, add more, take some away, etc.

My small contribution to overthinking it is to suggest that figuring out the best position for the tip of the iron to quickly inject heat into both surfaces is oft overlooked and, I think, one of the keys to success.

Late to the party, I know.  I am a real noob at soldering, missed the day we covered it in metal shop, around '78.  Tried a couple of times last year with the kit I bought that has a basic little 40w Weller iron, solder etc.  Found it quite difficult.

I'd seen YouTube videos etc. but still wasn't encouraged. Checked the specs of the kit I bought and learned they packed it with lead-free solder.  I took Doc B's suggestion above and sat down with an old circuit board, solder wick and some 63/37 solder.  What a difference !

By practicing on a bunch of joints it started to get easy !  The solder had a lot to do with that, but the timing needs to be right too it seems.  Looks like I just needed to practice on some non-critical stuff that I can make mistakes on and not be concerned.

Did the hardware assembly on my Quickie today, one more practice session soldering, and then I will finish up the Quickie.  Feel much more comfortable with the task, now that I've had some practice.  "Stop reading and start soldering."  It works.

[Strikkflypilot]

Ok, this thread is old but interesting.
I got some Johnson's IA-423 solder as I built the Crack.
Now, with the Mainline coming over the Atlantic, I might
get to use it, anyone with experience  with Johnson's IA-423?

[Paul Birkeland]

If at all possible, lead free solder should be avoided like the plague, especially if you are a new builder. 

-PB

[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?