Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Solder--let me bounce some things off you.

7285 views
49 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Solder--let me bounce some things off you.
Posted by SpaceMouse on Tuesday, September 29, 2020 8:39 PM

 I spent 9 hours building a turnout today, two of which were trying to get my soldering iron to work. It's an X-tronic 4000 Series, 4010-XR3 to be exact. That's it right there on my dining room table.

I could not get it to melt solder. I stuck the tip in flux, wiped it on a paper towl, used the blue sponge--nothing worked. I even took steel wool to it--and I finally got it to melt solder. But it was a cold joint. 

Finally, I went and got my 15 year-old RS 40W pencil and it worked about like it did before. I had tinned the tip.

The X-tronic didn't take to tin.

After I got the turnout to the point where I didn't think there was anything to make a loco derail--we"ll see about that , right? I got out the X-tronic and took a file to it. Then I polished as best I could with the steel wool. And you know what? 

It actually worked better than the Radio Shack. At least in terms of how fast it melted solder.

So, what should I be doing to take care of my tip? I mean, besides taking a file to it.

I need a new tip. What should I get?

And while I'm asking questions, how do I know whether to increase the heat or whether to decrease it.   

 

 

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    July 2007
  • From: Yorkton, Sk, Cnd
  • 441 posts
Posted by wvg_ca on Tuesday, September 29, 2020 8:47 PM

you should always tin your soldering tip before shutting it off, don't leave it clean and bare

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, September 29, 2020 9:10 PM

 And don't ever file the tip. You have likely now filed the plating off and while it may have worked for now, it will now quickly oxidize. At this point you should get a new tip. The tip should be shiny and bright. If it is dull and blackened - it's not going to melt solder very well. 

 Since it is adjustable - one thing to do is NOT turn it up as high as it goes - it is very rare that anything, including soldering track joints, in model railroading would need the max temp the station is capable of. The lowest settings are below the melting point of solder.

 As wvg_ca says, when you are done ussing it, you should melt a blob of solder on the tip and then turn it off. Next time you use it, once it heats up to melt that blob, wipe it off and you should have a nice shiny tip. You can also use a tip tinner, generally sal ammoniac, it comes in a little cannister, mine had a piece of double sided tape on it so I stuck it right on my station. Don;t overuse it - it eventually eats the plating off the tip, but once in each session, to get the tip clean, and then immediately add some solder to truly tin it.

 Also get yourself something like this, it works much better than a damp sponge:

https://www.amazon.com/Aoyue-Soldering-Cleaner-sponge-needed/dp/B005C789EU

 

This is an example of tip tinner: https://www.amazon.com/Thermaltronics-FBA_TMT-TC-2-Lead-Tinner-Container/dp/B00NS4J6BY/ref=sr_1_1_sspa?dchild=1&keywords=tip+tinner&qid=1601432001&s=hi&sr=1-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExMEZWQlNORllXWjk0JmVuY3J5cHRlZElkPUEwMzgzMjUzMTU3T0xHSExYRDRHOCZlbmNyeXB0ZWRBZElkPUExMDMzNTgzTFc0U1cyNzkyTlZCJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

 

                                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Tuesday, September 29, 2020 9:41 PM
Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,249 posts
Posted by tstage on Tuesday, September 29, 2020 9:53 PM

Chip,

First, you want a minimum of two tips: A chisel tip and a pointed tip.  The chiesel tip is great for maximizing the heat transfer from your soldering iron to your track.  Will your Xytronic soldering station accept other manufacturers soldering tips - e.g. Weller or Hakko?

Secondly, never...NEVER file, sand, or use any type of abrasive on the plating of your soldering tip to clean it.  A good tip is one that remains shiny.  If it's dull and won't tin and/or the plating is gone then it's time for a new tip.  The suggestion of melting a glob of solder on the tip before shutting your soldering iron down is a good one.  This will keep the tip from oxidizing when cold.  I do this even if I'm going to shut down my soldering station for only 5 min.

I would also suggest using the coiled brass "sponges" for cleaning your tips rather than the damp sponge method.  Regular sponges deteriorate and leave debris.  The brass sponges look like spiral wads of brass ribbon wadded into a ball.  The brass is softer than the plating on the solder tip.  I've been using the same chisel soldering on my Weller soldering station for years and it's STILL shiny.

For soldering decoders I keep the tip between 650-700oF.  For track you'll want to go higher - like 750oF.  It depends on how much surface you're trying to heat up.

Lastly, I would suggest getting a small jar of rosin soldering flux.  Your solder probably already has the rosin flux in it but I still like add a small toothpick dab of it on the area to be soldered to get that shiny solder joint when it's cool.  I have a 2 oz jar that I picked up at Radio Shack years ago and I've hardly made a dent in it.

Bottom line: Shiny soldering tip...shiny solder joints.  The former will always keep you from achieving the latter.

Tom

[Edit: Well, it looks like I just echoed pretty much all of the suggestions that Randy gave you.]

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Tuesday, September 29, 2020 10:18 PM

rrinker
 And don't ever file the tip. You have likely now filed the plating off and while it may have worked for now, it will now quickly oxidize. At this point you should get a new tip. The tip should be shiny and bright. If it is dull and blackened - it's not going to melt solder very well.

I felt I didn't have anything to loose. I ordered the tips, tinner, the brillo in a can, some .8mm solder and some flux. I'll use the RS 40W until the stuff arrives Thurs.

wvg_ca

you should always tin your soldering tip before shutting it off, don't leave it clean and bare

I tin my tips. That's why the RS worked after a two year hiatus. I can't imagine not doing it on the X-tronic. 

I am still completely lost at what tempurature to use. It will go from smoking paper to burning through brass. Searching the internet, asking on this forum doesn't net me a glimmer of a starting point. 

The best advice I got was to pick an number and fiddle with it. I picked 785F. It worked before but not today. I turned it up to 872F with no effect, until I filed it. So its now 872F. Is that in the ballpark?

What criteria do you use for going up or down? 

I'm going to have to do a lot of soldering in this hobby and I feel like I'm spinning my wheels. I watch videos of people touching irons to itty bitty electronic things and I have no idea of how to get from here to there.  

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Tuesday, September 29, 2020 10:27 PM

tstage
First, you want a minimum of two tips: A chisel tip and a pointed tip.  The chiesel tip is great for maximizing the heat transfer from your soldering iron to your track.  Will your Xytronic soldering station accept other manufacturers soldering tips - e.g. Weller or Hakko?

I just ordered Hakko 10 points, so it better. (They say it'll work on mine.)

tstage
Secondly, never...NEVER file, sand, or use any type of abrasive on the plating of your soldering tip to clean it.  A good tip is one that remains shiny.  If it's dull and won't tin and/or the plating is gone then it's time for a new tip.

Which is why I didn't worry about filing it. I knew I was going to order new tips.  And I know about tinning. Like I said above, I can't believe I didn't tin the X-tronics.

tstage
For soldering decoders I keep the tip between 650-700oF.  For track you'll want to go higher - like 750oF.  It depends on how much surface you're trying to heat up.

This is extremely helpful. 

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    July 2006
  • From: west coast
  • 7,667 posts
Posted by rrebell on Tuesday, September 29, 2020 10:58 PM

If you use 37% lead about 400 degrees is fine for temp. It melts at 361.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Tuesday, September 29, 2020 11:03 PM

rrebell

If you use 37% lead about 400 degrees is fine for temp. It melts at 361.

 

Close. I think I'm using 60-40. That's what I ordered today.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Tuesday, September 29, 2020 11:17 PM

gmpullman

Very helpful. The guy following up was interesting, too.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    September 2003
  • 10,582 posts
Posted by mlehman on Wednesday, September 30, 2020 1:18 AM

Chip,

Double check the tip to make sure it's tight. They can loosen up due to the heating and cooling cycle. When they do, the results are much like you describe above, highern settings seem to produce limited or no reults

Mike Lehman

Urbana, IL

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, September 30, 2020 1:38 AM

A little watch building:

Get good flux.  And I don't mean the GERN kind:  good non-acid 'no-clean' flux.  Use it regularly, use it a lot.  The most important part of soldering is good flux.

The 'plating' on a tip is more circumstantial than actually valuable: a plain copper tip properly cleaned, fluxed and tinned will transfer heat cleanly to the joint as well as any nominally 'nonstick' plating.  Just be prepared to be religious with FLUXING and then tinning and then cleaning your tip whenever you are starting and then whenever you are ending a session.

The special tip tinner is useful but it is not a full substitute for proper technique.  Think of it as solder paste for a slightly more specialized use -- and don't stint on either the fluxing and the tip cleaning.  

And get a bronze wool sponge for cleaning.  Use it frequently.  I don't like these made of wire wool; get one made with coarse lathe turnings or equivalent to give them edges and 'tooth' to scrape scurf off the tip...

Note that there are different types of solder,some of which are carefully formulated to melt over a very small range of temperature.  The 'correct' tip temperature is partly determined not by how hot the iron says it is, but by how hot the iron gets the parts of the joint the flux helps the alloy stick to.  This is why size and shape of tip sometimes matter -- and why the alloy and temperature range of what you tin the tip on a particular job should be picked carefully rather than thinking the difference is merely 'rosin core' vs. 'acid core' as picked up at Lowe's.

I know cost is an important issue for you, but since you have a reasonably good iron you should invest in good no-clean flux, a bronze sponge, perhaps a couple of different tips made for the station that you treat properly ... and several different compositions of solder with different liquidus points and ranges.

And 'hotter is not better' as long as your tinning and flux give you good heat transfer to the mass of metal in the joint.  You might have to tweak up 10-15 degrees over nominal liquidus as documented for your particular solder if using a small tips, or have to work with extensive heat-sinking arrangements or heavy mass or section of metal (there are better tools than irons if the sections get too heavy into the braze range) but experimentation will probably get you where you need.  872 degrees is wildly high; you'd be getting into jewelry grades of hard solder to require that ... and I doubt that's what you've bought, so tip hygiene and 'knowing your alloy' will get you back from soldering Hades, I suspect in fairly short order...

As noted, be sure your tip is kept tight.  Repeated cycles of heating and cooling can 'creep' either a threaded connection or setscrews loose, and while some modern tips put the temperature sensor close to the 'business end' some keep it and its necessary insulation safely in the handpiece.  (I have been tempted at times to "solder" the joint between tip and iron for better thermal conductivity, or figure out the best higher-temperature analogue for 'thermal compound' in electronic heat-sinking, but have been too lazy to experiment.  Be careful when tightening tips not to damage them or the structure they attach to...

  • Member since
    August 2020
  • 581 posts
Posted by Southgate 2 on Wednesday, September 30, 2020 2:22 AM

Hey, Chip, Do us a fave and let us know if those Hakko tips do in fact work on the Xtronic station?  I got the same Xtronic that you have. I haven't had any trouble with it, but I recon the day will come I need Tips...

I'll say this much. This variable temp soldering station took the extreme frustration and hatred out of soldering for me. Dan

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, September 30, 2020 5:07 AM

i've found that the tip may not be making good contact with the rest of the soldering iron.   spinning it, in your case, may help. 

you filing the tip probably moved it around and that helped it.

i'll hold a soldering tip up near my lips to sense how hot it is.   if it looks dirty, i'll spit on a paper towel and wipe it clean.  don't usually have to do it twice.

if there's solder accumlating on the tip, i'll just shake it off.   i've learned not to bang the soldering tip against anything because it can dislodge the thin wire in the shaft of some soldering irons used to heat it.

i'd rather keep my bench space free of unnecessary things like a water bottle or solder cleaner.   i keep a solder sucker handy

greg - Philadelphia & Reading / Reading

Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,249 posts
Posted by tstage on Wednesday, September 30, 2020 9:31 AM

One more item to add, Chip: A bottle of 91% isopropyl/rubbing alcohol for cleaning rosin flux from boards, wires, and/or track.  That you can pick up from your local pharmacy or order it from Amazon.  I also have a bottle of 99% isoproply handy for the same purpose.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    September 2003
  • 10,582 posts
Posted by mlehman on Wednesday, September 30, 2020 9:37 AM

tstage
A bottle of 91% isopropyl/rubbing alcohol for cleaning rosin flux from boards, wires, and/or track. That you can pick up from your local pharmacy or order it from Amazon.

Ordering from Amazon might work, but I haven't seen a bottle of 91% in any local store since the beginning of the pandemic...

Mike Lehman

Urbana, IL

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, September 30, 2020 9:42 AM

I prefer 63/37 solder - it DOES make a difference. 63/37 is eutectic - it all melts and freezes together, 60/40 is not, so there is a greater chance of making a cold joint.

800+ degrees is way too hot. My station is an old style with an analog knob, no digital readout, but I think the markings are calibrated (somewhat) in degrees celcius. I usually use around 400C, which is around 750F. Somewhat lower for fine wires like decoders, or small electronics. More like 650-700F for that. With a knob, it's also easy to flip down to the lowest setting if you need to do some work between soldering - it heats up rapidly, so it's not a loss of time, and the cooler you keep the tip, the less is oxidizes. I don;t turn it down if I am just setting it in the stand so I can place another component, but if I am setting the iron down so I can move things around, clip off excess leads, etc - a few minutes or more of work until I need to solder again, then I will turn it down.

 

                             --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Wednesday, September 30, 2020 12:52 PM

rrinker
I prefer 63/37 solder - it DOES make a difference

Only recently did I try out 63/37 solder, and I am happy I did. As Randy said, it does make a difference.

I have also found that 750 degrees is a good setting on the soldering station for soldering wires the track and rail joiners/track joints.

-Kevin

Living the dream.

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Wednesday, September 30, 2020 1:41 PM

The main thing to know is that good soldering is an acquired art, not a necessary evil. Practice on scrap material first with the wedge tip and fine point tip.

I have used a Weller WLC-100 station in the past with Radio Shack tip cleaner and damp sponge. Plated tips.

Cardas Quad Eutectic silver solder. Goes from liquid to solid faster than any other solder. I got it from Amazon. No extra temp on station.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Wednesday, September 30, 2020 5:36 PM

Mike

Chip,

Double check the tip to make sure it's tight. They can loosen up due to the heating and cooling cycle. When they do, the results are much like you describe above, highern settings seem to produce limited or no reults 

Good Tip! (aware of pun but don't endorse it.)

Dots - SignDots - SignDots - Sign

Overmod

A little watch building:

Get good flux.  And I don't mean the GERN kind:  good non-acid 'no-clean' flux.  Use it regularly, use it a lot.  The most important part of soldering is good flux.

On the way.

The 'plating' on a tip is more circumstantial than actually valuable: a plain copper tip properly cleaned, fluxed and tinned will transfer heat cleanly to the joint as well as any nominally 'nonstick' plating.  Just be prepared to be religious with FLUXING and then tinning and then cleaning your tip whenever you are starting and then whenever you are ending a session.

Makes total sense.

 

The special tip tinner is useful but it is not a full substitute for proper technique.  Think of it as solder paste for a slightly more specialized use -- and don't stint on either the fluxing and the tip cleaning.  

And get a bronze wool sponge for cleaning.  Use it frequently.  I don't like these made of wire wool; get one made with coarse lathe turnings or equivalent to give them edges and 'tooth' to scrape scurf off the tip...

Both are on the way. I'm going to be doing a lot of soldering in the near future. It will be a good investment.

Note that there are different types of solder,some of which are carefully formulated to melt over a very small range of temperature.  The 'correct' tip temperature is partly determined not by how hot the iron says it is, but by how hot the iron gets the parts of the joint the flux helps the alloy stick to.  This is why size and shape of tip sometimes matter -- and why the alloy and temperature range of what you tin the tip on a particular job should be picked carefully rather than thinking the difference is merely 'rosin core' vs. 'acid core' as picked up at Lowe's.

I know cost is an important issue for you, but since you have a reasonably good iron you should invest in good no-clean flux, a bronze sponge, perhaps a couple of different tips made for the station that you treat properly ... and several different compositions of solder with different liquidus points and ranges.

Next on my short list is some 63:37 solder. I thought 60/40 was best so it's all I bought for years. I didn't think there could be such a difference. Also on the list is a couple other tips of tips.

And 'hotter is not better' as long as your tinning and flux give you good heat transfer to the mass of metal in the joint.  You might have to tweak up 10-15 degrees over nominal liquidus as documented for your particular solder if using a small tips, or have to work with extensive heat-sinking arrangements or heavy mass or section of metal (there are better tools than irons if the sections get too heavy into the braze range) but experimentation will probably get you where you need.  872 degrees is wildly high; you'd be getting into jewelry grades of hard solder to require that ... and I doubt that's what you've bought, so tip hygiene and 'knowing your alloy' will get you back from soldering Hades, I suspect in fairly short order...

I thought 872F might be a little hot, but I wasn't sure.

As noted, be sure your tip is kept tight.  Repeated cycles of heating and cooling can 'creep' either a threaded connection or setscrews loose, and while some modern tips put the temperature sensor close to the 'business end' some keep it and its necessary insulation safely in the handpiece.  (I have been tempted at times to "solder" the joint between tip and iron for better thermal conductivity, or figure out the best higher-temperature analogue for 'thermal compound' in electronic heat-sinking, but have been too lazy to experiment.  Be careful when tightening tips not to damage them or the structure they attach to...

Thanks for the thoughtful reply.

Dots - SignDots - SignDots - Sign

Dan
Hey, Chip, Do us a fave and let us know if those Hakko tips do in fact work on the Xtronic station?  I got the same Xtronic that you have. I haven't had any trouble with it, but I recon the day will come I need Tips...

I'll say this much. This variable temp soldering station took the extreme frustration and hatred out of soldering for me. Dan

They are supposed to be here tomorrow. I'll let you know by Friday morning.

Dots - SignDots - SignDots - Sign

Greg
i've found that the tip may not be making good contact with the rest of the soldering iron.   spinning it, in your case, may help.

I admire your efficiency. I'll check the tip (not while I'm soldering.)Laugh

Dots - SignDots - SignDots - Sign

Tom

One more item to add, Chip: A bottle of 91% isopropyl/rubbing alcohol for cleaning rosin flux from boards, wires, and/or track.  That you can pick up from your local pharmacy or order it from Amazon.  I also have a bottle of 99% isoproply handy for the same purpose.

Tom

I've been using soapy water and a toothbrush, but I have a bottle of 91% by my layout.

Dots - SignDots - SignDots - Sign

Mike
Ordering from Amazon might work, but I haven't seen a bottle of 91% in any local store since the beginning of the pandemic...

I have a bottle pre-pandemic.

Dots - SignDots - SignDots - Sign

rrinker

I prefer 63/37 solder - it DOES make a difference. 63/37 is eutectic - it all melts and freezes together, 60/40 is not, so there is a greater chance of making a cold joint.

800+ degrees is way too hot. My station is an old style with an analog knob, no digital readout, but I think the markings are calibrated (somewhat) in degrees celcius. I usually use around 400C, which is around 750F. Somewhat lower for fine wires like decoders, or small electronics. More like 650-700F for that. With a knob, it's also easy to flip down to the lowest setting if you need to do some work between soldering - it heats up rapidly, so it's not a loss of time, and the cooler you keep the tip, the less is oxidizes. I don;t turn it down if I am just setting it in the stand so I can place another component, but if I am setting the iron down so I can move things around, clip off excess leads, etc - a few minutes or more of work until I need to solder again, then I will turn it down.

                             --Randy

IdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdeaIdea

You want 63:37 because the melting point is lower.

So you use less heat. 

And less chance of melting the plastic on those little blue DPDT switches with six posts. And on anything else you don't particularly want to melt. 

Dots - SignDots - SignDots - Sign

Kevin
Only recently did I try out 63/37 solder, and I am happy I did. As Randy said, it does make a difference.

I have also found that 750 degrees is a good setting on the soldering station for soldering wires the track and rail joiners/track joints.

-Kevin

I am just starting laying track, lots of joiners and feeders--and I still have about 25 more turnouts to make.

Dots - SignDots - SignDots - Sign

Rich

The main thing to know is that good soldering is an acquired art, not a necessary evil. Practice on scrap material first with the wedge tip and fine point tip.

I have used a Weller WLC-100 station in the past with Radio Shack tip cleaner and damp sponge. Plated tips.

Cardas Quad Eutectic silver solder. Goes from liquid to solid faster than any other solder. I got it from Amazon. No extra temp on station.

Rich

I'll keep an eye out. I order from Amazon a lot.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, September 30, 2020 5:50 PM

SpaceMouse
I've been using soapy water and a toothbrush, but I have a bottle of 91% by my layout.

There are probably better methods than  using soaps... the rosin itself needs to be converted to a 'soap' with alkali so it can be scrubbed/rinsed off.

Much of the discussion of rinsing rosin effectively is concerned with electronics soldering, particularly with SMDs and very small voltages and currents where even final rinse with deionized water requires very careful and sometimes extended drying.  Much of that discussion doesn't apply to 'structural' soldering for good electrical and logic conductivity... but be aware of context.

Removing rosin with solvent can be a pain because of redeposited film.  Note that water-based rinses will affect this little unless the rosin is saponified or the solvent is miscible with water; the tradition in electronics is to use a flood of solvent and agitation to carry it away.

Much of this is expeditiously solved by using a good no-clean in the first place, especially if using RA or RMA where the 'rosin' is more a vehicle for active ingredients than an active blanketing or oxygen-scavenging material itself.

 

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, September 30, 2020 6:01 PM

SpaceMouse
You want 63:37 because the melting point is lower. So you use less heat.  And less chance of melting the plastic on those little blue DPDT switches with six posts. And on anything else you don't particularly want to melt. 

The actual light-bulb moment involves something quite different.

The point of a eutectic is not the temperature at which it starts and finishes freezing, but in (a) the effective speed and (b) the metallurgical composition of the joint formation.

Think for a moment what a 'cold-soldered joint' actually is, and why it is unpleasant, then think what a good solder joint is.  The first point of the eutectic (and yes, the fractional-composition is still better than the integer approximation in some respects!) is that it freezes completely at a sharp and well-defined temperature -- there is no prospect of mechanical damage if the joint moves or there is any differential contraction across the 'sludge' in a solidifying non-eutectic joint.

Meanwhile what is happening during that sludging is that some of the alloy is dissociating into crystals of different substances, with the matrix of 'what's left' finally hardening around them.  This is not going to provide an optimal bond to even a clean substrate, or give proper internal structure.

The Cardas quad-eutectic is carefully formulated to have this sharp eutectic behavior for more than two alloying components, for better physical properties of the joints so made as well as 'different' solidus temperature.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Wednesday, September 30, 2020 10:29 PM

Overmod
There are probably better methods than  using soaps... the rosin itself needs to be converted to a 'soap' with alkali so it can be scrubbed/rinsed off.

I had two types of flux in my stuff from 15 years ago. Water-based and petroleum-based. The water-based had dried out so I ordered more. But I've still been working using the petroleum-based. I figured detergent breaks down petroleum products. I didn't want the petroleum products gathering gunk.

I sound like I'm talking about plumbing supplies.

Much of the discussion of rinsing rosin effectively is concerned with electronics soldering, particularly with SMDs and very small voltages and currents where even final rinse with deionized water requires very careful and sometimes extended drying.  Much of that discussion doesn't apply to 'structural' soldering for good electrical and logic conductivity... but be aware of context.

Although in context, it doesn't matter, I didn't get the SMD anagram, so I looked it up. There are 92. With electronics as schema, there were 3:

Surface-mounted device

Servo motor drive

Surface-mounted diode.

I elminated the diode because of context and added small micro devices, which is I guess, belongs in the Department of Redundancy Department. 

What is your background? Science or engineering?

Removing rosin with solvent can be a pain because of redeposited film.  Note that water-based rinses will affect this little unless the rosin is saponified or the solvent is miscible with water; the tradition in electronics is to use a flood of solvent and agitation to carry it away.

Should I be using a petoleum-based flux in Model Railroading?

Much of this is expeditiously solved by using a good no-clean in the first place, especially if using RA or RMA where the 'rosin' is more a vehicle for active ingredients than an active blanketing or oxygen-scavenging material itself.

Quite an education. I know now that there are a 5 types of flux. R, RMA, RA, NC, and WS. The water-based solvent is obviously WS. The petroleum-based flux can does not specify which it is, but it contains zinc cloride so that would make it RA or RMA. 

So, let's cut to the chase. You can be specific with brands if you like. What type flux would you use for track-work?

Feeder Wires?

LED lighting, signals, etc.?

Decoders and other electronics?

Itty bitty wiring in locomotives?

Keeping your tip clean?

Or is there a one-size fits all here?

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Wednesday, September 30, 2020 10:42 PM

Overmod
 
SpaceMouse
You want 63:37 because the melting point is lower. So you use less heat.  And less chance of melting the plastic on those little blue DPDT switches with six posts. And on anything else you don't particularly want to melt. 

 The point of a eutectic is not the temperature at which it starts and finishes freezing, but in (a) the effective speed and (b) the metallurgical composition of the joint formation.

Think for a moment what a 'cold-soldered joint' actually is, and why it is unpleasant, then think what a good solder joint is.  The first point of the eutectic (and yes, the fractional-composition is still better than the integer approximation in some respects!) is that it freezes completely at a sharp and well-defined temperature -- there is no prospect of mechanical damage if the joint moves or there is any differential contraction across the 'sludge' in a solidifying non-eutectic joint.

Meanwhile what is happening during that sludging is that some of the alloy is dissociating into crystals of different substances, with the matrix of 'what's left' finally hardening around them.  This is not going to provide an optimal bond to even a clean substrate, or give proper internal structure.

The Cardas quad-eutectic is carefully formulated to have this sharp eutectic behavior for more than two alloying components, for better physical properties of the joints so made as well as 'different' solidus temperature.

 

 
The Cardas quad-eutectic really jumps in price. Same question as above. What would recomend for specific applications?
 
I'm still not wrong. Faster joint formation and lower tempertures means a rank amatuer like myself is less likely to destroy things. 

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,249 posts
Posted by tstage on Wednesday, September 30, 2020 10:49 PM

Chip,

I just use rosin soldering flux, which should be the exact same flux found in rosin-core solder.  I use it for everything electronic.

As mentioned in my earlier post, you don't need much because it spreads when it's heated.  Generally, just a small dab on the end of a toothpick is enough.  Otherwise, you'll be cleaning off the abundance of melted flux from your decoders or PCB boards.

And you don't need flux for keeping your soldering tips clean.  The glob of cooled solder will protect the plating on the tip from oxidizing.  Whenever you heat up your soldering iron to use it again, just wipe off the excess then re-tin the tip with fresh solder and you're good to go.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, September 30, 2020 10:52 PM

 SMD here is surface mount device.

I use the same flux for everything. GERN, of course. No, just kidding. I have a water soulable brand called Solder Safe. But I don't use it everywhere. Soldering a feeder to rail? Use it. Solder rails together? Use it. Solder a component with a large lead, more of a solder lug than a PCB mount terminal? I'll use some. Soder resitros, capacitors, LEDs, etc. on circuit boards? What's in the solder is enough, I find, rather than getting flux all over my PCB. Still needs to be cleaned off afterwards. Soldering decoder wires? Don't use it. Again, for the small size of the wire, the flux in the solder is normally enough. I rarely put any flux on the tip of my iron. Keeping a coating of solder between uses, adn using the brass sponge thing to wipe it clean menas it is almost always shiny and clean - I'm still using the same tip it came with when I bought this thing something like 12 or 13 years ago. I've occasionally used others, different size/shape ones for different jobs, but the default one is the same one it came with.

 For heavier jobs, like soldering feeders to the bus, I have a big soldering gun, 150 watts or so it claims. And I use thicker solder, still 63/37. For electronics/decoders I have .010" solder, for the bigger stuff, it's like .032".

 I use the same style of flux, too - the paste. When I bought it, I also got some of their gel, but never really used it, it's too runny. The past stays where you put it. And since it's water soluable, if I need somethign thinner, mixing some with distilled water makes any thinner consistency I might want. Though I haven't really hit a use case for gel or liquid. 

                                 --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2004
  • From: Rimrock, Arizona
  • 11,251 posts
Posted by SpaceMouse on Thursday, October 1, 2020 1:28 AM

Randy and Tom--Good information. I'll probably have questions, just not tonight. 

I went through my solder--I have some left from long ago, and I inherted a bunch from my dad when he passed. I have various sizes of 60/40 (most of it largish diameter and two others of curiosity. 

1) a .010 62/36/2 solder by Radio Shack for electronics. 2% is silver

2)a "silver-bearing" lead-free solder that has a diameter the size of my little finger. Okay, it's more like 1/8 inch. 

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Thursday, October 1, 2020 2:18 AM

SpaceMouse
The Cardas quad-eutectic really jumps in price.

Its 'primary' use as I understood it is in fancy hi-fi equipment, to make 'perfect' joints for tweak audiophile satisfaction, a combination of mechanical strength and electrical conductivity.

It should work well for very precise fabrication, the sort where you use small chips of solid precisely where they will 'wet out' to a perfect braze layer with only a thin visible edge between the two pieces being joined.  Or in little balls for ball-grid-array computer chips, or the surface-mount devices that require small but very good attachment ... or decoder wire attachment.  

A point to remember is that a very little mass of this solder may go a very long way when used correctly or kept for 'special' work.  Think of it as like the Outerbridge's Sherry Pepper Sauce of solders... Wink

I'm still not wrong. Faster joint formation and lower temperatures means a rank amateur like myself is less likely to destroy things.

I did not mean to suggest that you were 'wrong' in saying what you did (or in valuing a solder's or an iron's capability to 'protect us from ourselves' sometimes).  It is just that that's not the primary reason for the 'goodness' of the stuff.

If I were not distracted with other things, I'd look into getting one of the LaserStar freehand laser rigs (which sell 'list' for somewhere in the $800 range),  Those do a wonderful job of flowing solder right where it's wanted while leaving adjacent components virtually untouched -- and with proper eutectics, allowing the 'made' joint and its neighboring structures to be promptly quenched without impairing the quality.  (The device can also be used for fusion welding of small sections, and for marking.)

Sorry for the salty technical talk.  I get carried away sometimes.  We've had a couple of discussions regarding SMDs and other small fabrication in recent threads and thought it was more well known to DCC aficionados than it probably is.

One good rosin 'remover' back in the day was a combination of ethanol (in these troubled times, the active ingredient in Everclear) denatured not with hexane but cyclohexane.  You would not casually use this to deflux something at the bench!  And in the days of soldering stations with hot air preheat handpieces, you would have the heat gun ready to hand to ensure that every little tittle of solvent was well evaporated from, say, an electronics board, before you tried testing it under power.  Solvent does get in under those little SMD devices, and dissolved rosin or other material, too if you let it, and at modern tiny currents and low voltages this can cause more problems than in typical model-railroad construction up until recently.

My advice about choosing 'fitness to purpose' is to browse a couple of the specialty 'soldering stores' on the Web, see what they offer and how they propose to use it, and ask pointed questions of their technical-support people.  Keep in mind that there are no stupid questions, especially at the early stages of learning, and many of the problems and issues do, in fact, already have reasonable solutions.

  • Member since
    October 2005
  • 1,047 posts
Posted by betamax on Thursday, October 1, 2020 5:36 AM

SpaceMouse

Randy and Tom--Good information. I'll probably have questions, just not tonight. 

I went through my solder--I have some left from long ago, and I inherted a bunch from my dad when he passed. I have various sizes of 60/40 (most of it largish diameter and two others of curiosity. 

1) a .010 62/36/2 solder by Radio Shack for electronics.

2) a silver solder that has a diameter the size of my little finger. Okay, it's more like 1/8 inch. 

 
Despite what many will claim, solder does have a shelf life. After a few years the lead begins to react with the flux, which becomes less effective.
 
Using fresh rosin flux will get around that issue, but flux has a shelf life as well. 
 
Soldering is a skill, and it takes some practice.  With the right tools and materials, and clean workpieces, it isn't hard once you get the hang of it. 
 
 
 
 
Tags: DCC , solder
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, October 1, 2020 8:23 AM

 Outerbridge's Sherry Pepper Sauce - I had to look that one up, and I am now looking for some - I love hot sauces, I have a rather large collection. It may be a good thing that issues these days prevented the usual hot pepper festival held locally here, as I usually spend a significant amount of money adding to and/or replenishing my collection. 

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!