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Soldering Question ... Something I've Always Found Very Challenging

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Soldering Question ... Something I've Always Found Very Challenging
Posted by nscsxcrrailfan on Tuesday, July 6, 2010 5:38 PM
Hi, I've been in model railroading since 2004, and I have always had trouble with soldering. I've tried all kinds of techniques with different irons. Every piece of advice I found seemed to require 3 hands, one holding the iron, one holding the solder, and one holding the feeder, which I've found impossible to do. The iron I've settled with now is a Weller 5-40watt soldering station (red and comes with a yellow sponge). A couple of years ago, I started using a technique where I would apply rosin flux on the end of the track feeder, put some rosin solder 40/60 on the tip, and then apply that to the wire, which would result in a tinned wire (I set the iron at slightly below half on the amount of power). I would then take some flux and put a very small amount using a toothpick on the side of the rail where I wanted the feeder (of course I cleaned it first with alcohol and a toothpick). I then put some more solder on the iron tip and touched the tinned wire to the rail and touched the iron to the wire and rail causing the solder on the wire, tip, and the flux to all combine creating a fairly good joint. This technique has worked for me, but everywhere I read, everyone recommends heating the rail first. I tried all sorts of techniques trying to heat the rail and every time, either the solder wouldn't melt or the ties would melt. So, I kept experimenting and finally came up with another technique that I want everyone's opinion on. Every piece of advice I read about recommends using maximum heat to quickly heat the rail and wire without melting the ties. So, I set the iron on maximum (40 watts) and cleaned it using the wet sponge that came with it. Then, I applied a tiny amount of flux to the spot where I want my feeder. Next, I cut the feeder wire and stripped the end of it. Once the iron was heated to maximum temperature, I applied a very small amount of solder to one side of the tip (I'm using the original flat screwdriver looking tip that came with it). I then took the wire and placed it on the rail where the flux was and applied the iron's tip to the wire and rail and heated it for 2 seconds using the side of the iron without any solder, then I turned the iron over where the solder was attached and re-applied the iron, this time the solder flowed into the feeder joint very nicely. I have discovered that using this technique seems to result in a harder to break connection and results in a smooth flowed out solder connection. I tried this same technique at 3 and 5 seconds and both times I ended up with melted ties. An individual on Youtube recommended laying down wet cotton balls on both sides of the place to be soldered to help prevent melted ties. I haven't tried that yet, although I plan on doing so soon. So, is this method of soldering o.k. or am I likely to run into problems down the road? Should I heat the rail and wire longer than 2 seconds (at 40watts)?
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 5:40 PM
Also ... I forgot to mention that I am in N scale using Atlas Code 55 track.
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Posted by luvadj on Tuesday, July 6, 2010 5:43 PM

I use heat sinks on both sides of the rails when I solder, but occasionally, I still get a melted tie or two. I've found get it hot and cooled it down again as quick as possible works for me.

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Posted by Hamltnblue on Tuesday, July 6, 2010 5:56 PM

make sure the surface you are soldering to is nice and clean.

Pre drill the hole for the feeder. Then use Solid wire for the feeder and do a small bend at the tip.  About a half inch from the feed kink the wire so that the feeder is pressed into the rail when you lower the wire. That way you don't have to hold it.  It will hold itself.  Use flux on the joint.  When soldering place the iron at the spot where the wire and track join.  Use a very thin solder so that it melts quickly.

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Posted by bpickering on Tuesday, July 6, 2010 5:59 PM

luvadj

I use heat sinks on both sides of the rails when I solder, but occasionally, I still get a melted tie or two. I've found get it hot and cooled it down again as quick as possible works for me.

Heat sinks of one form or another. I typically use a couple of clamps, one on either side of the feeder. I've also recently read about using wetted tissue paper, being a similar concept to the wet cotton balls. However, the key is what luvadj said- get the heat on as quickly as possible, get things melted properly, and let it cool off.

I use a 45W iron for track-work, so the 40W is probably in the right range. 15W or 25W will probably take so long heating to melting temperature, that even with heat sinks, the surrounding material will heat up to the point where ties start melting.

Brian Pickering "Typos are very important to all written form. It gives the reader something to look for so they aren't distracted by the total lack of content in your writing." - Randy K. Milholland
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Posted by gandydancer19 on Tuesday, July 6, 2010 5:59 PM

 The object is to get a good bond and a joint that looks wetted.  (Just like wetting in scenery.)  The faster the better as long as the result is good.

What I do is this:  (I use a temperature controlled station and heat it to the equivalent of a 40 watt iron, about 700 degrees F.)

Clean the rail with a scratch brush.  Strip the wire and bend it to the shape needed to lay against the rail.  Apply a small amount of rosin flux.  Wipe the irons tip on a wet sponge then apply it and the solder to the rail as close as I can to the feeder wire.  (I apply the solder to the tip of the iron first then move it to the rail.)  When the solder melts, move the iron to include the feeder wire.  As soon as I see the solder flow on the feeder wire I remove the iron. 

If I can't get the wire to stay against the rail, I will apply solder to the tip and then apply the iron to the rail on the flux.

When I apply the solder to the iron first and it melts, it then flows to the rail.  When it flows to the rail, it carries or conducts the heat to the rail which helps heat it up more quickly.   This heat transfer is of prime importance, just like starting with a clean area to be soldered.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

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Posted by howmus on Tuesday, July 6, 2010 6:21 PM

nscsxcrrailfan
A couple of years ago, I started using a technique where I would apply rosin flux on the end of the track feeder, put some rosin solder 40/60 on the tip, and then apply that to the wire, which would result in a tinned wire (I set the iron at slightly below half on the amount of power). I would then take some flux and put a very small amount using a toothpick on the side of the rail where I wanted the feeder (of course I cleaned it first with alcohol and a toothpick). I then put some more solder on the iron tip and touched the tinned wire to the rail and touched the iron to the wire and rail causing the solder on the wire, tip, and the flux to all combine creating a fairly good joint. This technique has worked for me

 

I'll play the devils advocate here and tell you that your original technique is right on base.  The trick is using separate rosin flux. I use a 25w Weller using a similar technique taught to me by a man who made a living repairing sound equipment.  He learned it from his father who learned it in the Air Force.....  I clean the rail and do the entire joint in one easy process.  Yes, I get perfect results every time and I can solder a rail feeder onto code 70 flex in less than a second.  Here is a short video of a clinic I gave  last year for the local NMRA.  http://s66.photobucket.com/albums/h259/slow_rr/SLOW_RR_II/?action=view&current=SolderingTech2.flv

On the layout I have now I have soldered around 6,000 joints.  Guess how many have failed.... (0)  And... no melted ties.  I do not use heat sinks.  Sometimes I pretin, but not always.

A little theory -  Heat is transferred to the joint mostly where the metal of the iron is contacting the metal of the metal being heated.  Remember that air is an insulator.  A dry iron has very little contact area, so the heat is transferred slowly allowing the heat to travel down the track melting ties as it goes, but won't easily get hot enough where the joint is to melt the solder or if it does you may get a cold solder joint.  Having a small drop of solder on the tip of the iron increases drastically the contact surface allowing heat to be transferred quickly from both the drop of solder and the entire (very hot) iron.  The result is a lot of heat right where you need it.  You are done quickly and before the heat travels away from the joint to do damage.  That phenomenon is the reason some people recommend a larger iron and a flat tip on the iron.  More contact area, quicker, better, and safer results.

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

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Posted by dstarr on Tuesday, July 6, 2010 8:38 PM

 Try a pair of alligator clips from Radio Shack.  They do double duty, they hold the feeder wire in place, and they act as heatsinks to reduce the amount of tie melting.   I clean my rail with a wire brush in the Dremel. Tinning the feeder is helpful, it carries solder to the joint and doesn't need a third hand to do it.  Rosin flux is good.  Unless the rail is ultra clean, and the Gods smile upon you, the rosin core of the solder won't give enough flux for a clean joint.  Forty watts is on the small side for soldering to rail.  I use a 200 watt Weller soldering gun myself.  

   You want the tip of the iron or gun to be tinned, covered with silvery molten solder.  A tip wet with molten solder will flow more heat, faster, into the rail than a black, dry, and crusty tip will.  As for how long to heat the joint, you look at the solder.  When the joint is hot enough, the solder will melt, wet the rail, and flow into a  smooth drop shape.  Soon as that happens, the joint is hot enough and you can remove the heat.  The cool solder joint must stay shiny.  A white frosty look is called a cold solder joint and must be reheated before it is reliable. 

 

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Posted by abbieleibowitz on Tuesday, July 6, 2010 8:51 PM
All of the techniques mentioned throughout this thread work and really, there are few differences between them. I don't have a magic solution that will blow anyone away, but I have found that the key to soldering is to get the piece hot quickly and get out just as fast. So my most important contribution is that I always have a wet paper towel nearby when I solder feeders to track and when I solder rails. I've had melted ties even with heat sinks, but I have had the best success by rapidly cooling the joint by pressing the wet towel to the track as soon as I take the iron away. The little "sizzle" tells me it's cool. I remember reading somewhere that if you cool the joint too quickly you can get a brittle solder joint that won't hold, but that has never been a problem for me using this technique. Abbie
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 9:21 PM
O.k., I went back and did some more practice. This is what drives me crazy. The second technique that I thought was better worked good on an old turnout I had however it melted the ties like crazy on a piece of flex track I practiced on. So, I turned the heat down from 5 to 4 and the same problem occurred. I shortened the time to 1 second and still ended up with melted ties. In addition, I'm afraid to turn the iron up to 4 or 5 now because the tip turns purple/blue. When I put solder on it the flux just evaporates instantly and I'm left with just a little bead of solder metal on the end. I cannot tin the tip with the iron set above 3 1/2. The last technique I tried was to turn the iron down to 3 1/2, tin the wire, use as little solder and flux as possible, and hold the iron on there for 1-2 seconds. Question: I've been told that the tip I'm using is too big and is transferring too much heat. It's the original one that came with the iron. It's wide and looks like a flat screwdriver head. However, I would think that by using a pencil tip that I would have to hold the iron on there longer to get it up to the right temp resulting in more melted ties. Then again, perhaps the bigger tip is spreading the heat out more than necessary resulting in melted ties. Any thoughts on this??? Also, one thing I've noticed is that if I take my iron tip and just place it on the rail, it takes 5-10 seconds before the ties start melting. However, when I use the flux and solder, they melt sometimes almost instantly. I wonder if the flux is getting really hot and spreading out, carrying the heat to the ties and melting them. Also, in general (Audio equipment, home electrical, layout wiring, etc...) how important is it that the wire be hot before you apply solder? Many times I have to touch the solder against the iron tip and make sure to use flux to get a good solder connection. Should I always make sure the wire is hot enough to melt the solder on its own without having to touch the solder to the tip or is it o.k. for the wire to simply be very warm?
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 9:24 PM
Also, I tried alligator clips as some have suggested. The problem is that when I use them they won't grip very good to my Code 55 rail, and the only way I can get them to hold onto the wire is to have one grip into the insulation which melts as soon as the iron touches the wire/rail.
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 9:36 PM
howmus

nscsxcrrailfan
A couple of years ago, I started using a technique where I would apply rosin flux on the end of the track feeder, put some rosin solder 40/60 on the tip, and then apply that to the wire, which would result in a tinned wire (I set the iron at slightly below half on the amount of power). I would then take some flux and put a very small amount using a toothpick on the side of the rail where I wanted the feeder (of course I cleaned it first with alcohol and a toothpick). I then put some more solder on the iron tip and touched the tinned wire to the rail and touched the iron to the wire and rail causing the solder on the wire, tip, and the flux to all combine creating a fairly good joint. This technique has worked for me

 

I'll play the devils advocate here and tell you that your original technique is right on base.  The trick is using separate rosin flux. I use a 25w Weller using a similar technique taught to me by a man who made a living repairing sound equipment.  He learned it from his father who learned it in the Air Force.....  I clean the rail and do the entire joint in one easy process.  Yes, I get perfect results every time and I can solder a rail feeder onto code 70 flex in less than a second.  Here is a short video of a clinic I gave  last year for the local NMRA.  http://s66.photobucket.com/albums/h259/slow_rr/SLOW_RR_II/?action=view&current=SolderingTech2.flv

On the layout I have now I have soldered around 6,000 joints.  Guess how many have failed.... (0)  And... no melted ties.  I do not use heat sinks.  Sometimes I pretin, but not always.

A little theory -  Heat is transferred to the joint mostly where the metal of the iron is contacting the metal of the metal being heated.  Remember that air is an insulator.  A dry iron has very little contact area, so the heat is transferred slowly allowing the heat to travel down the track melting ties as it goes, but won't easily get hot enough where the joint is to melt the solder or if it does you may get a cold solder joint.  Having a small drop of solder on the tip of the iron increases drastically the contact surface allowing heat to be transferred quickly from both the drop of solder and the entire (very hot) iron.  The result is a lot of heat right where you need it.  You are done quickly and before the heat travels away from the joint to do damage.  That phenomenon is the reason some people recommend a larger iron and a flat tip on the iron.  More contact area, quicker, better, and safer results.

I watched your video and what I think I'm doing wrong is worrying way too much about getting the rail hot. With model RR track you just can't get the rail very hot without melting ties. ALSO ... Is it much of an issue if I just always apply a bead of solder to the iron and rely on separate flux to do my soldering? I'm asking this because I know that the flux boils away when the solder is applied from the iron's tip instead of from a separate spool.
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Posted by howmus on Tuesday, July 6, 2010 10:14 PM

nscsxcrrailfan
I watched your video and what I think I'm doing wrong is worrying way too much about getting the rail hot. With model RR track you just can't get the rail very hot without melting ties. ALSO ... Is it much of an issue if I just always apply a bead of solder to the iron and rely on separate flux to do my soldering? I'm asking this because I know that the flux boils away when the solder is applied from the iron's tip instead of from a separate spool.

 

The addition of a good rosin flux (I am using the liquid flux from Micro Mark) is really the secret of the technique.  The big reason many sources tell you not to do it the way I do is that the rosin burns away as soon as you put the solder on the iron.  The use of flux at the joint being soldered allows the solder to flow into the joint as the rosin does its job of cleaning the area to be soldered.  That is also why I don't worry too much about pretinning the wire or the rail.  It all happens at once. BTW, sometimes I will add a bit more solder to the joint, but usually there is plenty of solder in the drop on the iron to do the job.  Oh, and the rail gets very hot, right at the spot where the joint is made.  It will then spread down the rail.  But since you used enough heat to do a good joint in a small spot, the temp doesn't get so hot it will melt ties nearby.  As I mentioned in the Video, yes, you may damage the little fake "spike right under the place you are making the joint, but that is all.  Practice, practice, practice!

The black stuff that accumulates on the iron is burnt rosin, BTW.  I clean the iron frequently with the same brass brush you saw in the video.

One other thing.  This technique I only use for electrical work!  I do something much more "traditional" when building Fast Tracks Turnouts or other soldering work.......Wink

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 10:15 PM
Essentially what I'm worried about is trying to get a good solder connection without melting ties while avoiding a cold solder joint. Question: How hot does Nickel Silver have to get before it will melt solder on its own? Is it too hot for the plastic ties? Is it o.k. to use flux as a crutch since without out we get hot nickel silver but melted ties?
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 10:20 PM
I posted right at the same time that you responded to my questions. That seems to answer most of my questions, but I still want to know if in general (Audio equipment, home wiring, etc...) if it is o.k. to rely on flux instead of heating the wire/rail to hot temperatures? I had to apply some solder to some old stereo speakers a few weeks ago, and I heated the wire first and then applied solder. It seemed like it took a long time to heat up though.
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Posted by howmus on Tuesday, July 6, 2010 10:49 PM

nscsxcrrailfan
I had to apply some solder to some old stereo speakers a few weeks ago, and I heated the wire first and then applied solder. It seemed like it took a long time to heat up though.

 

Did you cut the wire back to make sure it isn't corroded?  That is usually what I find when I have had problems doing that...  Fixing audio equipment was how I learned the technique.  (I owned a Music Recording/DJ Business for about 15 years.)  The molten solder will aid in transferring the heat quickly into the connection.  When using stranded wire (like audio wire), I usually like to pre-tin the wire before actually making the joint.  Seems to work better.

nscsxcrrailfan
if it is o.k. to rely on flux instead of heating the wire/rail to hot temperatures?

 

Answer?  Yes.  The rail will get hot enough to make the joint.  As soon as you see the solder flow into the joint, it is done.  That will happen usually in a second or less.  You want a quick transfer of the heat.

Here is a photo of the finished result:

Also another short video from the clinic showing other electrical soldering using the technique.  Notice where i am holding the wire....  If I touched it half an inch closer to the joint, i would have burned my fingers.  I let go when the wire got hot.......

http://s66.photobucket.com/albums/h259/slow_rr/SLOW_RR_II/?action=view&current=SolderingTech1.flv

BTW, I don't solder home wiring.... Something about the code....Whistling

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 10:57 PM
Yeah, I cut the speaker wire ends off and stripped off insulation to apply a new coat of solder. Looking across the internet, it seems like there is a division between those who prefer smaller wattage irons and stations and those who prefer the big solder guns for model railroading. I have an old solder gun, but I always have trouble with it burning the tips out. There are many who strongly recommend making sure the rail is hot enough to melt the solder by itself, but I don't see how you could do that without melting the ties. It might not be that big of a deal because it does seem like Nickel Silver gets much hotter than 14awg or higher copper does.
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Posted by tinman1 on Tuesday, July 6, 2010 11:06 PM

 

I'll chime in on this. Trying to heat the wire with a dry tip means only a small area of the tip is touching the wire. With a bit of solder on it, the area being heated is much greater. I think your missing the whole temp/time thing. There is no set time, and temp has only a minimum. There are many different types of solder and they have different melting points. I think I've seen them down to 300F and goes up from there. Once the solder flows, the temp is good. Solder will look like a bead if the temp is not hot enough on one of the metals, but will look flat when it does flow. You don't need a big blob to get the job done, it's not a structural thing. I use a little flux on the parts to be soldered, and a little solder on a pencil tip iron. Normally its a 40W, but I use a 25W for smaller items. I also use plumbers putty for a heat dam. It's cheap, available everywhere, will conform to any shape, and shunts heat well.
Tom "dust is not weathering"
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Posted by nscsxcrrailfan on Tuesday, July 6, 2010 11:55 PM
O.k., I found a website that talks about flux and refers to situations like ours where we cannot heat the wire/rail first before applying solder. Here's what the website said "For typical through-hole component soldering, heat is applied to the components, and then solder is melted directly on those components. Part of the reason that solder is applied directly to the parts and not the iron is that if applied to the iron first, the flux would likely burn off before being able to clean the joint. Unfortunately, in surface mount soldering, the leads are too small to apply solder to them directly, so it must be applied to the soldering tip first. To ensure that active flux is available when the joint is being made, it's necessary to apply additional liquid flux directly to the joint. The extra flux also reduces the solder's surface tension which helps it wick into the small connection areas. Flux also acts as a blanket that helps to spread heat out and prevent additional oxidation from occurring before solder reaches the joint. The main trade-off with flux is its activity level. Higher activity means it will help solder cling to metals faster, and also be able to handle heavier oxidation and much more stubborn oxidation (stainless steel, aluminum). The downside to higher activity is that residues left over can be corrosive and destroy components, be conductive themselves, or provide an environment that allows conductive tentacle-like "dendrites" to grow. Because of this, use the mildest flux that does the job, and if a more active flux is needed, clean thoroughly." So, basically either method is correct. From what I understand, in model railroading (specifically track feeders & rail joints) you can use either a big soldering gun to heat the rail quickly and apply solder from a spool or you can use a lower watt iron and apply solder to its tip (not referring to tinning which is done with either method) and use extra flux on the connection. With the second method, the solder does not need melted because it already is and is at a very high temperature. Of course, applying it directly would not work because the flux would likely be gone. However, using an external supply of flux on the area fills in that missing part of the equation. So basically, the molten solder on the tip of the iron is equivalent to using a 250 watt gun, except the gun is not needed because the solder is already heated far beyond its melting point. I think I understand it. If the experts here see any errors in my understanding of this please let me know, and thank you for all the advice I have received so far.
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Posted by Allegheny2-6-6-6 on Wednesday, July 7, 2010 12:15 AM

 Read Jim Hediger's article in this moths MR about soldering track feeders etc. I think you'll find it very informative. The most important things you can do to become a good solder is practice practice practice

Make sure your iron is always clean and you final solder joint is nice and shinny a dull looking joint is a sure sign of a cold solder joint. In my opinion there is no such thing as overkill when it comes to soldering.as far as having a higher wattage iron then necessary. A higher wattage iron simply menas your work surface will heat up faster and give you less change to melt ties

Just my 2 cents worth, I spent the rest on trains. If you choked a Smurf what color would he turn?
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Posted by cordon on Wednesday, July 7, 2010 2:44 AM

Smile

Although someone briefly mentioned it above, I didn't see any emphasis on tinning the rail.  It really makes the rest of the job go much easier.  Here are the steps I go through:

     Apply a small amount of flux to a small surface of the side of the rail.

     Apply flux to the tip of the iron.

     Apply a small amount of solder to the tip of the iron and wipe the tip on the damp sponge.

     Touch the solder and the tip of the iron to the side of the rail where the flux is.  Remove both immediately after the solder melts, which should happen in about a second.  The result should be a smooth and shiny layer of solder on the side of the rail.

     Tin the end of the wire and place/clamp it so that it leans against the side of the rail where you have tinned the rail.

     Apply a small amount of flux to the assembled joint.

     Apply flux to the tip of the iron.

     Apply a small amount of solder to the tip of the iron and wipe the tip on the damp sponge.

     Touch the tip of the iron to the joint just long enough for solder to melt and flow.  It should happen in about a second.  The result should be a shiny layer of solder smoothly blended over the wire and the rail.

Another possible problem is the type of tip on your soldering iron.  I participated in a couple of threads three years ago in this forum on the relative performance of iron tips and copper tips.  You can find these by doing a search on "solder tip question" in Model Railroader Forums.

Smile   Smile

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Posted by Forty Niner on Wednesday, July 7, 2010 7:53 AM

For better than 40 years now I have never soldered wire directly to the rail, I "always" solder it to the bottom of the rail joiner instead. I can take a group of rail joiners to the work bench, solder them up and have enough to last for several days of track laying at one time.

I also use a "small" torch or my soldering "machine", something I learned as a result of soldering on brass engines.

And, I only use "Tix" solder and flux, a small bit of Tix flux, then the heat and it flows beautifully and it's a very strong bond.

The soldering gun and the "Home Depot" solders I reserve for using on the wiring such as the feeders or most any under the table soldering.

The main thing is I solder it to the rail joiners, haven't melted a tie since I started doing it this way.

Mark

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Posted by nscsxcrrailfan on Wednesday, July 7, 2010 10:15 AM
I've made a lot of progress when it comes to soldering. When I started out about 5 years ago, I made the worst looking solder connections you could imagine. I was in HO Scale then, and I thought I had to have big globs of solder using heavy duty wire. The solder I used was some old acid base stuff (really big sized), and I didn't even use flux. Flash forward to today, and now I'm using a Weller station with rosin 60/40 solder. Just recently, I started using rosin flux. I had been using an old flux that we had bought about 20 years ago. It turns out I think it was acid base although I'm not sure. I might have some rail connections turn white in a few years but by then I'll be on to another layout. The layout I'm working on now is Layout 3, and even with the mistakes I've made on it, it is still much better than the previous two layouts I have built.
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Posted by duckdogger on Wednesday, July 7, 2010 11:47 AM

 An alternative to soldering the feeder, or even just the joiner to 2 sections of track, is to use some of the Fast-Tracks  copper clad  PC board crossties. They are pre-gapped so they don't create a short.

I remove one or two of the flextrack (or turnout ties) at a rail joint, insert a PC board tie aligning the inside of each rail with the gap in the cladding.  I then apply my solder to the tie at the joiner.  You can also include your feeder wire, or solder it separately to the underside to the tie before installing.

You avoid melting ties (although I still apply a heat sink) and avoid creating a high spot where the joiner would have rested on the plastic ties.  Lastly, you maintain the track's gauge as the gaps in the PC board ties match the NMRA clearance dimensional standards.

Trains. Cooking. Cycling. So many choices but so little time.
  • Member since
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  • From: Franconia, NH
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Posted by dstarr on Wednesday, July 7, 2010 1:33 PM

 The purpose of flux is to remove corrosion on the surface and let the molten solder touch clean metal. As the soldering iron heats the work, the hot metal starts grabbing oxygen molecules out of the air and forming a coat of unsolderable oxide.  The flux counter acts this and keeps the surfaces clean, long enough for the solder to adhere to the metal. 

  They make acid flux and acid core solder.  These are for plumbing work only.  Never use acid flux for electrical work.  The acid stays active, and is strong enough to corrode small wires thru given a few years. Always use rosin flux.  The rosin flux is only active when it is hot and melted.  Cool and solid, it doesn't corrode stuff, or at least the corrosion rate is a whole bunch less than acid flux.  

  The flux lets the solder wet the work.  If the solder beads up into little ball shapes,  the work is dirty or oxidized and the solder isn't making contact with bare metal.  

  Always use 60/40 tin lead solder.  60/40 has the lowest melting point, about 190C, or twice boiling water.  Hot enough to melt plastic.

  Avoid 50-50 solder, that's only for plumbing.  The recent anti lead phobia has resulted in a lot of "lead free" solders.  I don't trust them.  Tin lead solder has been around for thousands of years and it bonds well and stay bonded.   

  The tip of the iron or gun MUST be tinned.  That means covered with a silvery coat of melted solder.   Keep a damp sponge on the bench to wipe the hot tip on and keep it bright.  If the tinning wears off or burns off you must renew it.  Or replace the tip.

  When a well tinned tip is pressed to the work, the melted solder flows to the work and makes a solid connection that will flow huge amounts of heat.  If the tip looses its tinning, it takes forever to get the work hot enough.

 

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Posted by 1948PRR on Wednesday, July 7, 2010 2:03 PM

The OP is absolutely correct.

You DO need three hands.

This is just a fact.

 

I had mine grafted on in the 1980's, but for a different reason.

It has served me well in soldering, though.

  • Member since
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  • From: Hampshire, England
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Posted by germanium on Wednesday, July 7, 2010 2:44 PM

I use a temperature controlled station with a heat indicator. When the control shows that the iron has reached the correct temperature, I always allow five minutes before  tinning the iron. This ensures that the temperature is correct.

Dennis 

 

  • Member since
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  • From: Missouri
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Posted by nscsxcrrailfan on Wednesday, July 7, 2010 10:14 PM
O.k., I spent all day working on the layout, mostly soldering. I tried a variety of techniques. This post is somewhat lengthy due to all the steps involved in the two methods I tried today. First, I got out my old soldering gun. It is 100/140 watt. At 140 watts, I waited until the gun heated up and tinned it with some solder. Then, I cleaned the tip with the sponge that came with my Weller station. I applied the tip of the gun to one side of the wire that I was going to use as a feeder and the wire instantly heated up. The solder melted without the need of any extra flux. I cleaned the spot on the side of the rail where I wanted my feeder. I then applied the tip of the gun to the place where I wanted the wire and applied solder. The rail heated up and melted the solder without melting any ties. Then, I applied a tiny amount of flux to the cooled off solder. I then placed the tinned wire right up next to the solder & flux on the side of the rail. Then, I applied the gun to the top of the rail and the tinned wire and solder/flux on the rail melted and fused together. I held the gun on long enough to see the solder on the wire and the solder/flux on the rail boil, melt, and fuse together. I did not have any ties melt. At first, I thought I had found a better way of making feeder connections (almost identical to the methods recommended by most model railroaders), however upon inspection I noticed the solder was a light white color (cold solder appearance). I waited a few seconds and reapplied heat and ended up with the same result. I tried the same technique on a rail joiner to see how the gun would handle that. I applied a small amount of flux and touched the tip of the gun to the top of the rail joiner. I then applied solder to the joiner, which melted after 1 second. The problem this time was the rail turned dark brown/black and even melted a few ties. The solder dried a white color. So, I went back to my Weller Station and used my original method. I stripped the wire and applied a small amount of flux to the bare part of the wire. I made sure the iron's tip was tinned and cleaned with the sponge. Then, I held the iron to the wire and applied solder, which melted onto the wire (the flux accelerated the melting). Then, I cleaned the area where I planned on placing the feeder. I applied some flux to that spot. With the iron already tinned, I added a small bead of solder to the tip (the iron was on the middle setting 3 approx. 25 watts). I touched the wire's tinned end to the cleaned area where the flux is and placed the iron's tip to the rail/wire. The solder bead flowed from the iron's tip onto the flux, mixing with the solder already tinned on the wire. I removed the tip and allowed it to cool. The result was a somewhat shiny connection, rather than the white looking solder I got with the gun. I tested it by pulling on the wire. This was a test connection so I yanked about 5 times on the wire and it pulled away just a little but was still secure on the rail. I then gave it a really good yank, even bracing my hand on the track while I pulled and it finally came off. Now, with my soldering of wires without track, I found the gun to do a little better job than the iron. I had three 22awg wires twisted together, and with the iron on 3, I was able to get solder to melt within a few seconds. However, I couldn't get the solder to melt on a connection between 22awg wire and 14awg. I turned the iron up to 5 (max. at 40 watts) and the solder melted within a few seconds without the aid of flux or touching the solder to the iron. I tried the gun on the wires, and it melted the solder within a few seconds on both 22awg connections and 14awg. So, from my experience, the Weller Station seems to do a better job overall. Even though I cannot heat the rail using the Weller iron without the risk of melting ties, it still seems to create a very good connection using flux (without flux I think it would be impossible due to the boiling away of the flux on the soldering iron's tip). QUESTIONS: In General, if your solder connection is somewhat shiny and silver and holds without breaking by giving it a few gentle tugs, is it a good connection or not? AND ... to the person that was talking to me last night about the method I use with the Weller Station who had videos demonstrating this method, do you use this same method on heavy wire or do you completely heat the wire and allow its heat to melt the solder? I remember you stated that you use this same method on small audio wires. For the most part, can you create good solder connections in every situation without heating the metal by relying on flux and hot solder already melted on the iron's tip to rapidly heat the metal? I know I might be running this in the ground, but other than model railroading, I have virtually no experience with soldering on smaller or larger scales, such as electronics or piping, etc....
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Posted by howmus on Wednesday, July 7, 2010 10:38 PM

nscsxcrrailfan
to the person that was talking to me last night about the method I use with the Weller Station who had videos demonstrating this method, do you use this same method on heavy wire or do you completely heat the wire and allow its heat to melt the solder? I remember you stated that you use this same method on small audio wires. For the most part, can you create good solder connections in every situation without heating the metal by relying on flux and hot solder already melted on the iron's tip to rapidly heat the metal? I know I might be running this in the ground, but other than model railroading, I have virtually no experience with soldering on smaller or larger scales, such as electronics or piping, etc....

 

Think that was me......  You could use the same method with 14awg wire, but.....  You would certainly get much better results using an 80 or 100 watt iron.  I used to work for a telephone company as a summer hire.  I spent a whole summer back in the 1960s soldering telephone line connections inan x-y office in Victor, NY.  For that we used very large, very hot irons to do the job even with 24 or smaller wire.  The wire was wrapped around a flat connector, then the iron was placed on one side, and the solder was touched to the other side.  Again the joint was always good and done very quickly.  But...  There was nothing to melt so a lot of heat meant very quick and good work.   Personally I would not use a solder connection on very large wire in the first place.  If you must, that is the time to bring out the heavy artillery.

The technique I was talking about (which I see you found works well...) I use for small electrical connections like soldering on Tortoise Machines (where too much heat can damage the machine), toggle switches (where the same is true), Spade lug connections to small wire (where it just is the easiest way), and for rail connections with drop feeders for power (without melting plastic ties, etc...).

The key to all of this is as a couple of have said,  Find a way that works well for you and Practice, practice, practice.  If you had to tug hard to get the joint to separate, you had a good joint IMHO.  It is a solder, not a weld.

73

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

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Posted by nscsxcrrailfan on Wednesday, July 7, 2010 10:54 PM
howmus, o.k., so you mostly use this technique as a secondary option when it the normal technique of heating the object poses a risk of melting surrounding parts such as the ties or the plastic parts on a tortoise switch machine. However, you use the regular method on devices where there is no risk of melting anything nearby. That sounds reasonable as I simply cannot make a good solder joint on track without melting the ties using the regular method of heating the rail and allowing it to melt the solder on its own. The picture you posted of your solder connection looks very close to the connections I make. I don't think that mine are as flowed out as your photo but they're very close. I definitely don't end up with any balls of solder that are easy to pry off. I used to end up with balled up solder when I first got back into the hobby in 2004. Also, I mentioned earlier that the solder I used to use was acid base. It turns out that it was rosin core solder that was very large in diameter and was very old. However, the flux I had been using up until a few weeks ago had zinc chloride in it, which I think is acid based. I'm using rosin flux now. When I think about it, I don't understand why the hot solder hitting the rail and flux would not create a good joint due to the fact that the solder has sat on the iron for several seconds and is already heated well beyond its melting point. When the ball of molten solder leaves the iron and flows into the flux on the rail, it should carry enough heat to heat the rail to a very hot temperature long enough to make a good connection. I could see how this wouldn't work with large wire such as 14 or 12awg due to the fact that a small drop of hot solder would not have enough heat on its own to heat the entire section of wire to a hot enough temperature to make a good solid connection. Of course with wire connections, one is not really concerned that much with melting anything; the insulation can simply be taped or patched using liquid electrical tape.

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