Bottlehead Forum

General Category => Tech Tools => Topic started by: Schroeder77 on November 07, 2013, 07:52:36 AM

Title: Solder Choices
Post by: Schroeder77 on November 07, 2013, 07:52:36 AM
This is my first post here. I've purchased a Crack which will soon be delivered, and I'm considering the best solder. 

In searching for balance between the easiest to use/best quality solder for this project, it seems Kester 44 63/37 (which makes it eutectic?) rosin core at a .031" diameter fits the bill.

Is this a good choice, and is the diameter appropriate?

I am grateful that there is a community for this kit building: I thought I'd be soldering alone, but now I see that soldering can be a joint effort.

I am so sorry for that. :-) I can't promise it's the last one either.
Title: Re: Solder Choices
Post by: debk on November 07, 2013, 08:32:52 AM
LOL!

I use Kester solder

Debra
Title: Good Choice!
Post by: Grainger49 on November 07, 2013, 08:39:33 AM
That sounds fine.  A small diameter solder allows you to put on how much you want to.  For me, large diameter solder heats up slowly and is always a blob when it liquifies.
Title: Re: Solder Choices
Post by: Schroeder77 on November 07, 2013, 10:13:39 AM
Thank you for your replies, I will now purchase it confidently.

 :)
Title: Re: Solder Choices
Post by: Paully on November 08, 2013, 10:29:41 AM
I think you will be fine.  I just decided, in the end, to steer clear of silver solder.  Man that stuff can be hard to desolder if you mess something up.
Title: Re: Solder Choices
Post by: mcandmar on November 08, 2013, 11:23:42 AM
You cant go wrong with Kester solder, using a cheap solder can be the most infuriating experience imaginable.

I bought a few meters of Cardas Quad Eutectic Silver solder to try and that stuff melts and flows like hot butter, virtually impossible to create a dry joint with it, just lovely shiny joints time after time. I was very impressed with it, but it does seem to have a lot of flux inside so lots of scrubbing is needed to clean the board after.  I haven't tried to unsolder any of it but i don't see why that would be an issue, if anything i think it has a lower melting point than regular 60/40.

Now led free solder, that is a royal PITA to unsolder...
Title: Re: Solder Choices
Post by: aragorn723 on November 09, 2013, 12:10:42 PM
Hi, I have a similar question, but am building a quickie.  The solder I have is Radio Shack rosin core 60/40.  Is that good for audio, or should I go with something more high-end?
Title: Re: Solder Choices
Post by: Paul Joppa on November 09, 2013, 01:18:46 PM
I've used rosin-core 60/40 pretty much since the 3rd grade. It works great.
Title: Re: Solder Choices
Post by: Paully on November 09, 2013, 01:36:41 PM
Well, Paul Joppa has already responded so I think you are set, but that Radio Shack 60/40 is what I have been using since I started and I have never felt a need to upgrade.
Title: Re: Solder Choices
Post by: aragorn723 on November 09, 2013, 02:27:33 PM
This is my first post here. I've purchased a Crack which will soon be delivered, and I'm considering the best solder. 

In searching for balance between the easiest to use/best quality solder for this project, it seems Kester 44 63/37 (which makes it eutectic?) rosin core at a .031" diameter fits the bill.

Is this a good choice, and is the diameter appropriate?

I am grateful that there is a community for this kit building: I thought I'd be soldering alone, but now I see that soldering can be a joint effort.

I am so sorry for that. :-) I can't promise it's the last one either.

Let's keep those dad jokes coming, lots of Dads around here i'm sure  8)
Title: Re: Solder Choices
Post by: aragorn723 on November 09, 2013, 03:42:10 PM
Well, Paul Joppa has already responded so I think you are set, but that Radio Shack 60/40 is what I have been using since I started and I have never felt a need to upgrade.

Thanks for the feedback, I wasn't sure if Radio Shack was up for the job.
Title: Re: Solder Choices
Post by: Schroeder77 on November 10, 2013, 09:22:16 AM
I have a followup question, just a bit divergent from my original thread topic . . .  Let's just upgrade the thread to "Solder(ing) Choices" in this case.

In my YouTube tutorial research, some people suggest putting a bit of solder on the tip of the iron a few moments before soldering each connection (called "tinning" the tip?). The primary justification was to better conduct the heat.

However, I saw another video of someone strongly suggesting not to do so, mainly because the rosin core burns away and throws off the balance of flux/solder. 

While both arguments seem plausible to a novice like me, I'm assuming the latter takes priority. Any opinions regarding this?

Also, here's what the Pace soldering training video seems to suggest the most of the process:

1. Heat to joint.
2. A bit of solder between heat and joint to "bridge"
3. Apply solder to other side, "painted on," allowing the flow to cover joint, remove while iron is still on
4. Pull away heat, do nothing (as in blow, let it move, etc.)

Steps 1-4 should take place within 2 seconds to avoid damaging the components.

Are there any additions, disagreements, or points of clarification that I seem to be missing here?

Should I instead make a new thread called "soldering technique?" I saw some related here threads that have been unused for quite some time.

Thanks again everybody!



Title: Re: Solder Choices
Post by: Paul Birkeland on November 10, 2013, 09:38:39 AM
I don't really think it's necessary to tin the tip before each joint.  The amount of solder that it takes to tin the tip is generally pretty minimal compared to the solder used for your average solder joint (except maybe on a PC board).

Once you've done a joint or two, your iron should stay relatively tinned.
Title: Re: Solder Choices
Post by: mcandmar on November 10, 2013, 10:09:12 AM
There are two sides to this, the first as pointed out above is to clean/prep the tip so its got a nice shiny layer of solder on it.  This only needs done once in a while, you can tell by looking at the tip as it will go dull when it needs refreshed.

The second which i suspect is what the articles are aiming for, is to aid the thermal transfer between the iron and parts you are soldering.   For example for something with a large thermal mass like the body of an RCA socket having a little pool of solder on the iron greatly increases the surface area for the iron to conduct heat though. With a dry iron you could end up holding it on the socket for minutes wondering why your solder wont melt. Even for small through hole components a small dab of solder on the tip can help heat the board and part evenly allowing you to get in and out quickly.
Title: Re: Solder Choices
Post by: Doc B. on November 10, 2013, 10:21:03 AM
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.
Title: Re: Solder Choices
Post by: Grainger49 on November 10, 2013, 10:24:36 AM
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.
Title: Re: Solder Choices
Post by: Schroeder77 on November 10, 2013, 01:23:26 PM
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
Title: Re: Solder Choices
Post by: airdronian on January 19, 2014, 01:06:55 PM
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.  ;D 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.
Title: Re: Solder Choices
Post by: Strikkflypilot on November 30, 2014, 05:32:10 PM
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?
Title: Re: Solder Choices
Post by: Paul Birkeland on December 01, 2014, 09:31:37 AM
If at all possible, lead free solder should be avoided like the plague, especially if you are a new builder. 

-PB
Title: Re: Solder Choices
Post by: Doc B. on December 01, 2014, 09:40:07 AM
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.
Title: Re: Solder Choices
Post by: Strikkflypilot on December 01, 2014, 07:58:28 PM
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...
Title: Re: Solder Choices
Post by: Paul Birkeland on December 02, 2014, 06:45:53 AM
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.
Title: Re: Solder Choices
Post by: Strikkflypilot on December 02, 2014, 08:28:29 AM
Will make a good testrun before I put it to any serious work, then
Title: Re: Solder Choices
Post by: Strikkflypilot on January 05, 2015, 04:50:55 AM
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.
Title: Re: Solder Choices
Post by: Strikkflypilot on January 06, 2015, 12:00:40 AM
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. :)
Title: Re: Solder Choices
Post by: mcandmar on January 06, 2015, 03:27:03 AM
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.
Title: Re: Solder Choices
Post by: Strikkflypilot on January 06, 2015, 04:11:46 AM
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?
Title: Re: Solder Choices
Post by: mcandmar on January 06, 2015, 04:49:27 AM
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.
Title: Re: Solder Choices
Post by: Strikkflypilot on January 06, 2015, 10:04:56 AM
Do You use IPA on all solder joints, or just boards?