Soldering.....need advice.

[Santa Fe all the way!]

Im going to be making a few hundred soldered connections(feeders) and need advice on soldering. Ive been practicing by soldering 20ga wire to the underside and sides of scrap rail with crappy results. I end up with too much solder and still not a good bond between wire and rail. Any advice?? I've used my Radio Shack entry level and a battery operated iron. I tin the rail, then I cant get the wire to "stick" to the rail????Also, the solder wants to ball up and go everywhere but where I need it.

[jeffrey-wimberly]

 Most of what you're doing is correct but you're missing a couple of things. Here's what I do. I file a spot on the outer edge of the rail then dab some paste flux on it. I then dip the end of the wire in the flux then tin the wire end. Next I place the wire end in the paste flux on the rail then I put the tip of my soldering gun against the wire so it pushes the wire against the rail and touch the solder to it and the joint is made. Takes about 4 seconds once you get it down. The higher wattage your soldering tool the less time it takes. I used to use a 35 watt iron but it took so long to heat the rail that it melted the ties. Now I use a Weller 100/140 watt soldering gun and I don't melt the ties anymore.

[TomDiehl]

First, the two metals to be soldered need to be clean. First note: new does not equal clean. The rail surface needs to be buffed clean with an abrasive like an eraser or soldering brush. I use a typing eraser, the type you sharpen like a pencil. Then the wire also needs to be clean. Usually stripping new wire will give you a pretty clean surface, the flux will finish the job. Next the soldering iron tip needs to be clean (see a pattern here?) as in no flux residue on it. A wet sponge or wire brush will work for this, when hot the tip should be a shiny silver color. A very light coat of flux is needed on both pieces before soldering, a light coat because it needs to vaporize before the solder will join them.

For the actual soldering, the metals to be joined, in this case the rail and wire, need to be hot enough to melt the solder, which means the iron will have to heat both metals at the same time.You do NOT want the iron to melt the solder and drip it on, it won't stick. Get a bubble of melted solder on the tip of the iron to help transfer the heat from the iron to the metals. Touch the iron to the metals using the bubble of solder to transfer the heat, the flux will vaporize. Do NOT breathe this vapor or get it in your eyes. Touch the solder to the joint area and it should melt into the joint. Remove the iron and solder wire and allow it to cool. Clean off the flux residue.

[Hamltnblue]

First with the basics.  What type of track do you have?  Brass, Steel or Nickle Silver?

Next, what wattage is your soldering iron?

last, we assume you are using flux solder, that is solder with flux inside of it..

 

[cacole]

 It sounds like your soldering iron is not hot enough (too low a wattage) and you are not using the proper resin core electronics solder.

[mokenarr]

 also make sure the solder flows thru out the joint...  I do not put the iron directly on the joint , but right next to the   wire..  then touch the solder on the wire when the solder melts you know the whole joint is hot, and the solder will flow completly into the wrap...  the idea is to get the wire hot enough to melt the solder without the solder directly touching to iron..

also make sure the wire does not move until the solder is hard

 

if you iron is not hot enough or dirty this will take to long and cause problems , like melting the wire or ties

 

i am not sure what kind of iron that is , but i know a 110volt one will hold its tempurature good.  if you iron is losing it heat real quick you will get a cold solder joint , as the solder will not flow

[Santa Fe all the way!]

I'll try to answer your questions and thanks for the info so far. Im using a 15watt, cheapo Radio Shack iron. The track is Atlas nickel silver code 83 flextrack.The solder has flux in its center. Sounds like I need to get some paste flux. I've had expereince soldering copper plumbing, is the paste flux different for small electronic stuff than plumbing?? I've got the book, Reliable Track and the soldering abilities of the guys are probably out of my reach. Soldering 22ga wire to the sides of rail and you cant even see any solder...thats talent.

[joe27]

http://www.handlaidtrack.com/videos.php

This is a link to the fast tracks video that shows what everyone is trying to explain. Tim gives a great explanation of what to do and as they say "a picture is worth..."

 

Have fun, Joe

[nfmisso]

Santa Fe all the way!

 using a 15watt, cheapo Radio Shack iron

Get an elcheapo 40 to 50 watt iron or 100/140 watt gun.  And as others have said, cleanliness.

Do NOT use plumbing flux, get some electronics grade flux in a can, like this:

 http://www.radioshack.com/product/index.jsp?productId=2049774

clean, flux, tin, join.

[jeffrey-wimberly]

Santa Fe all the way!

Sounds like I need to get some paste flux. I've had expereince soldering copper plumbing, is the paste flux different for small electronic stuff than plumbing??

Yes. The flux used for plumbing has an acid base. DO NOT USE THIS ON YOUR TRACK! Radio Shack sells a non-acid paste flux that works well with the small amount of flux in the solder (which I've found is never enough). Just be careful though. A dab will do ya. Anything more will make a mess.

[howmus]

Santa Fe, you have been given some excellent advise so far.  Everything needs to be clean.  I like to use solid wire for the connection to the rail as it can be bent to stay put while soldering.  You don't need a very big iron or gun to do the job.  I use a Weller 25w for soldering to rail and most other hobby jobs.  25w to about 40 watt usually works well.  Your 15 watt is a bit small I would say.'

I really like the liquid rosin flux sold by MicroMark for all my electronic soldering.  Flux Pen

I also use a small drop of solder on the tip of the iron.  It allows the parts to heat up very quickly (the molten solder makes a much larger surface of contact to the job than the tiny tip touching the parts).  Often I don't have to add any more solder than what is on the iron.  In and out in less than 2 seconds doing track.  One second for most other jobs.  The object is to get enough heat in just the area you want soldered.  Even a 25 watt iron has plenty of heat in reserve to do the job if the heat is transfered quickly.  I have done about 5000 joints in the last 5 years using this method taught to me by a professional electronics repairman.  (I was in the live sound business for many years and had to use my soldering skills often with very fine wires and connections.)

Practice, practice, practice!

73

[tomikawaTT]

If you're getting 'blobs' of solder there is probably contamination on the surface you're trying to solder to.  Flex track right out of the box is often still coated with the lubricant used in the drawing dies, that's why it has a 'greasy' feel.  Older rail (especially brass) forms corrosion products that are very solder-resistant.

The cure is cleaning - something abrasive to get down to clean metal.

The second 'must have' is a good HOT soldering tool, with enough mass in the tip to stay hot when in contact with rail and wires.  Small-wattage irons usually fall short in this department, not because of the power rating but because of the small needle-pointed tips (which are ideal for soldering circuit boards and such.)  For any soldering involving rail I use a BIG Weller gun (325 watts!)

The third 'must have' is flux.  I personally use paste rosin, just a tiny dab on the end of a flat toothpick is plenty.  Avoid acid flux (and acid-core solder) unless you can wash the soldered area with a heavy solution of baking soda, followed by clear water.  The rosin in rosin-core solder is usually, "Too little, too late."

Fourth - are you using the proper solder.  You'll get the best results with 60-40 or 63-37 lead-tin solder.  Stay away from the lead-free stuff unless you're planning to eat off the soldered joint.  It may be child-friendly, but it's a PITA to work with.  Also, if you use small-diameter solder it's easier to control the amount you're adding to the joint.

Hope this has been helpful.

Chuck (Modeling Central Japan in September, 1964 - with about a million soldered joints)

[Allegheny2-6-6-6]

I personally do not like battery soldering irons I prefer the plug in one I have a resistance soldering unit from where I used to work but prefer using a simple 40Watt soldering iron.

A few  things to remember, clean the surfaces you want to solder, flux, tin the wires, a good iron and a steady hand.

Go find the video section on the new Realistic Reliable Track book and check out the bullet proof track wiring section Andy better explains it then I can he's a master at it.

I have to ask how big is your layout if your soldering that many drops. If your building an average size layout thats way more then you need.

[betamax]

By balling up, the surface is probably contaminated.

First, better iron. Get something that is at least 60 watts, with a chisel tip. Hot is good.

Also get some rosin flux. That will help.

The secret is to clean the pieces to be soldered if they are dirty. Try not to handle them too much after cleaning. Once they are in position, add a small amount of flux. With a hot iron, clean and tin the tip, then apply it to the joint, and add a little solder. The heat will activate the flux, and your solder should just flow nicely.

[7j43k]

Without, essentially, disagreeing with the previous posts, i will say that:

I've done milspec soldering.

I used Ersin 5-core solder, about 20 gage. After leaving that job, I bought my own supply--a pound--I still have it.

I used a flux that was a liquid (not acid). It was kind of sticky. When the joint was done, the flux had hardened and could be "chipped" off. The flux went on as a viscous liquid. When it was heated, it hardened. When it had cooled off, you could pick off the brittle pieces--if you so chose. The flux I use now doesn't seem to harden like in the old days, but it works beautifully--there's just a kind of sticky mess left behind--not like "the old days".

I bought a resistance soldering rig. I solder my track leads to the bottom of the rails. I do it on flex track and also Walthers/Shinohara switches. I solder leads to the frogs and also to each of the points. I solder to the bottom of the rails so that you can't see the joint after the job's done.

It's worked very well for me.

Ed

[Robt. Livingston]

I'm in the process of building my railroad, with soldered rail connectors (Flex track and pre-fab turnouts) and plenty of block feeders.  To clean the rail sides for soldering, I use a Foredom flexible shaft tool (like a Dremel)  that hangs on an old floor lamp stand.  I can move it around the railroad as I go.  The tool has a circular wire brush that cleans and polishes the sides of the rail where the feeder wire or rail joiner goes.  It works great, takes no time.  A typical Dremel would be a little more convenient, but I don't have one.   

[dstarr]

 Number of things.  Rail takes a good deal of heat.  To get a good solder joint you have to heat the rail hot enough to met the solder.  Unless the rail and the wire are hot enough to melt the solder by them selves you won't get a good joint.  You cannot melt the solder and let molten drops of solder fall onto a cold rail and expect it to stick.  To heat rail I use a 200 watt  soldering gun.  Irons ought to be at least 60 watts and 120 watts ain't too much.  Irons want a chisel tip to transfer heat faster.  The tip of irons and guns must be coated with molten solder (tinned is the proper word) .  When a tinned tip is touched to the work the liquid solder makes good contact with the work and allows heat to flow quickly into the work.  Use a pair of allegator clips as heat sinks to reduce the amount of tie melting.  

  Second, the solder has to "wet" the metal.  If it is balling up, the surface is dirty and/or you lack flux.  Molten solder is like water in some respects.  On some surfaces water beads up, on others it spreads out and runs every where.  You can tell when the solder is wetting the metal, the solder will spread over the hot metal surface.  If it stays in a ball shaped drop, the solder is not wetting the metal. 

Heated metal oxidizes very rapidly, it just grabs oxygen out of the air and the surface turns into metal oxide (to which solder won't stick) in a flash.   Flux is the answer to this problem.  Flux is a chemical reducing agent that converts the oxide back into metal.  Rosin flux (the only kind to use) activates  with heat.  Flux has to work pretty hard to overcome the heat induced oxidation.  Don't make life harder for flux by expecting it to clean existing oxide off the work.  Clean the work piece first.  A gritty eraser, a wire brush, or a wire brush in a Dremel tool all work well.

   Use 60-40 (or 63-37 which is the same thing with a different label) tin lead solder.  Avoid the 50-50 tin lead solder, that is only for plumbing.  Avoid the "lead free" solders, they don't stick well, require more heat and are expensive as hell, being mostly silver.  Avoid acid flux and/or acid core solder.  The acid will over time corrode the joint to uselessness.  Acid is only for plumbing.    

 

[Seamonster]

You've received a lot of good advice here. I'll add my own and repeat what has already been said for the most part.

Clean, clean, clean. The rail's going to be dirty (as far as soldering is concerned) and will likely have lubricant from the drawing process on it. If nothing else, clean the spot with alcohol. Clean soldering iron tip. Wipe the tip before making the connection. There are iron holders with wet sponges for wiping the tip on. Crud builds up on a soldering iron tip rather quickly. After wiping it, put a dab of solder on either side of the tip. A wet tip (one with a little solder melted on it) conducts heat faster than a dry tip.

Rosin core solder. ONLY rosin core solder. NEVER use an acid core solder. 60/40 rosin core solder sold for electronic work, or 65/35. It comes in various diameters. I use 0.75 mm diameter solder because I use it for electronic work too, but a slightly larger size may be better for you. It comes in one pound spools, which would last you a lifetime, but you can get smaller amounts at electronic distributors or Radio Shack.

I use a paste flux but liquid flux is just as good and is easier to apply. Again ROSIN flux. NEVER use acid flux. Apply a small dab to the rail.

Soldering iron. I know I'll get flack for this, but I don't recommend a 140 watt gun. I have a 45 watt iron and for my N scale rail I dial down the heat a bit. I've soldered HO scale rail with it and it's plenty hot enough for that. I use a 1/8" chisel tip in the iron.

As for technique, here's how I do it. Clean the rail side. Put a little dab of flux on the rail. Prepare the end of the wire by bending the end at 90 degrees for about 1/8". Tin the end of the wire. That means heating it with the iron and touching it with solder so that the end of the wire is coated with solder. Then I press the tip of the iron into the flux and touch the rail with solder so that it's coated. Then I press the end of the wire against the solder on the rail and touch the iron to the wire. The solder on the wire and on the rail melt instantly and the wire is bonded to the rail. It may sound complicated but it really isn't. It's quick and easy.

The trick is to use a hot iron and get in and out quickly. If you have a hot iron, you won't have to hold the iron on the rail for more than a second or two and you won't melt ties or have to put any kind of heat sink on the rail. Your 15 watt iron is totally inadequate for soldering to rail. If the solder is balling up, it's a combination of dirty rail and not enough heat.

[Dane1]

Hello Everyone. Glad to be in the Greatest Hobby! This is my first reply,so bare with me. As to your (?) . I learned from my dad who repaired TV, radios along time ago, and also MRR. This is what I was taught, and it's been good so far. I have code 100 rail, 20ga. feeders to 14ga. buss. 135w gun, the gun is big enough to pinpoint the heat faster than the rail/buss cools the gun. Above posters are right having things clean. Dirt soaks heat. Clean and tin tip of gun, strip feeder and twist end,then tin. Use flux core solder. Hold feeder to side of rail with tip of gun. When you apply heat and see the tin on the feeder start to melt, just touch the solder to tip. When the solder flows out, remove the heat. All this takes seconds. Practice on some scrap. The cleaner you keep the gun tip, the better. I also dip the gun tip in soldering paste before I tin it. Some VERY excellent modelers here, I've learned alot.  Hope this helps.    Try my first post later. I type super slow.