So I started soldering my first sections of track this weekend. The excitement builds as I’m finally laying my first track.
I’ve read that it should take only a second or two of holding the soldering iron against the flextrack in order to melt the solder. So I did. . . nothing. 5 seconds. . . nothing. 10 seconds, 20 seconds, 30 seconds. . . solder won’t melt. I switch the multi-watt iron from 20 watts to 40 watts and let it heat up. 30 seconds on the track again and the 60/40 solder won’t melt when I touch it to the track.
Out of curiosity (can’t resist at this point, can I??) I touch the solder to the iron and it instantly liquifies into a fine mess.
I was holding the iron to the top of the rails and the solder right below it. Any thoughts on what I’m doing wrong?
I’m DYING to lay track and post some pictures. . . I’m so close. . . please help!
Clean the area to be soldered. Some folks use flux or soldering paste for this (not acid), I use a wire brush on a dremel. Put the soldering iron on the rail joiner against the rails. Touch the solder where the joiner meets the rails and it should melt and draw Towards the heat. 40w should be plenty. Your problem is likely dirty materials and possibly, the iron tip.
The iron also needs to be tinned. A damp sponge (or paper towel) Not soaking and dripping, but damp. Wipe the tip on the sponge and place some of the solder on the tip. Repeat a couple times until the tip is nice and shiney. Dirty materials and iron will lead to exactly the frustration you are experiencing.
I’ve been soldering my track recently in preperation for an operating session, and I found that it is almost impossible without applying rosin flux (available at RadioShack for $6.59) to the joint first. It’s a lot easier, and soldering makes a huge differance in smooth operation.
Soldering is easy, if you know what you are doing. Good soldering takes practice and developing a technique is required. Practice on scrap track. I use a scratch brush to clean the joint and I use rosin flux with rosin core solder. Also, use Patience. Rushing is the Best way to frustration.
I used to use a 30 watt soldering iron and ALWAYS had problems getting solder to transfer to the rail, even when using a flux. I got a 100 watt soldering gun and never looked back. Soldering problems were a thing of the past. I use a non-spill soldering flux paste and Dutch Boy lead free solder (tin and copper).
All the above recommendations are VERY SOUND ideas. I will also add a couple of others.
1) Only solder on the outside of the rails, never on the inside. That way, you will not get any lumps of solder forming where the wheel flanges can hit and cause possible de-railments.
2) Only use a small amount of Flux. I am in “N” Scale and I use the small end of a toothpick to smear a small amount of Flux along the top side of the rail joiner against the rail web. As soon as I put the iron against the base of the joiner, the Flux starts to melt and runs between the joiner and the rail. After 2 - 3 seconds, I touch the very fine wire solder that I use to the top of the joiner. It melts almost instantly and runs along the joint and inside between the rail and joiner. I remove the iron as soon as the solder starts to melt so I don’t melt the ties. (Hint!!! make sure that your iron is HOT before you start to solder.)
If you follow the advise of the previous posters and myself, I think that you will soon be running trains on some solid track work.
Eight steps to a perfect solder joint, guaranteed to work every time:
Clean the parts to be soldered - no oil, corrosion or paint allowed.
Tin the parts (apply a tiny film of solder where you want the parts to join.)
Secure the parts so they will absolutely, positively NOT move.
Flux the joint - a tiny dab of rosin paste or a droplet of liquid rosin. NO acid, EVER!*
Apply heat - lots of heat, fast. For rails and structural soldering my weapon of choice is a 320 watt Weller hand cannon. Save the low-wattage pencil iron for fine wiring and circuit boards. (Note - if you get serious about soldering, you will need both.)
Apply solder to the heated, pretinned, fluxed joint. It should flow right in.
Remove the heat source as soon as the solder flows. Don’t move anything else until you see the solder solidify.
If something moved and you have a cold joint (crackly, dull-looking solder) reheat at once. A good solder joint will have a smooth, glazed appearance.
If you’ve never soldered before, it’s a good idea to practice on some scrap material first.
Yes, I know that a certain purveyor of turnout fabricating jigs swears by acid-core solder. My half-century of experience causes me to swear AT acid-core solder.
I use a Weller D440 145/210 watt soldering gun myself. You might consider a bigger iron. Tip has to be bright and shiny, tinned with solder. If the tinning burns off exposing the underlying copper or iron tip, you have to retin the tip before it’s going to work well. In bad cases I have had to file the tip down to clean metal, and flux the bejesus out of it before the tip will tin. Iron tips are particularly difficult. The molten solder on the tip makes good contact with the work and allows heat to flow more readily from the iron to the work. A burned off black dry iron takes forever to heat the work, the black crud acts as a heat insulator.
You have to use rosin paste flux. Just a little dab will do you. I use 60-40 rosin core tin lead solder, but for rail, the rosin core isn’t enough you need. Rail and rail joiners often spend years on store shelves before they come to you. In that time their surfaces corrod
Some excellent advise given here. The only thing I do in addition to the above (Chuck’s post) (using a trick from a gentleman who has spent his life repairing electronics) is to use a small drop of solder on the tip of the iron. The melted solder will transfer the heat very quickly to the joint. And, no, it will not cause a cold solder joint! As soon as the solder “flows”, remove the heat. Often I do not add any more solder than what I have on the iron. You want a lot of heat in a very small area otherwise you end up melting ties. I use a 25w iron for most of my hobby work. It provides plenty of heat if you have your technique down. I am done in less than 2 seconds with any of the rail joints.
Practice, practice, practice!
A close up of a solder joint on a feeder, code 83 Atlas rail, 22 gauge wire.
Lots of great tips for soldering here. I prefer a 200 watt model which does the job on code 83 rail in about a second or so, and solder all of my track and turnouts together, cutting electrical gaps, where required, with a cut-off disk in my Dremel.
A couple of things that might have been overlooked: if, by some chance, the rail is brass, you’ll need to clean it until it’s shiny, then use the methods suggested. The other, admittedly unlikely, situation, is if your rail is steel - you will not be able to satisfactorily solder it together.
The larger soldering iron does have the advantage of not melting plastic ties. One might think just the opposite but when you can get in there, heat up the metal and get out as soon as possible, the heating stays local to the tip area (where the tip touches the rail). Smaller wattage irons tend to take too long sometimes, allowing the heat to radiate to other areas, and softening or even melting the plastic ties. One way to avoid this if it becomes an issue is to use a heat sink. A simple alligator clip local to the rail joint area will help keep heat from spreading to the surrounding ties. Some people lay a wet (damp) paper towel over the tie area to keep the rails cool above them as well. The heat sink Will draw heat so a larger iron may be required anyway.
Whatever you do (to the OP), blow a few rail joiners and practice practice practice. You’ll be an expert in no time.
That’s simply not true. Clean steel will solder just as well as clean brass, or nickle silver. Use flux, the right solder, and a good iron.
I’ve scratch built many slot cars from spring steel plate, steel piano wire, and brass. No issues soldering any of the material, even to dis-similar materials.
All: thank you very much, you’re all so helpful. I read quite a bit before trying my first solder but apparently it didn’t all stick in the ol’ coconut.
I had no idea the flux was so important for brand new rail. I had assumed that it was not necessary because I have repeatedly read that I should make sure my surfaces are clean–well, I thought, you can’t get more clean than “brand new”. Guess I was wrong, and I can understand why based on the responses above. Flux it is. Anything that makes my life easier for under $10 is worth the cost!
I have heard advice varying from 25 watts to 350 watt mega-melters (?!). With a 40 watt model on code 83 track, will I really have to hold it against the track for an unreasonably long time if I apply flux next time?
No! if you do it well, it will take around 2 seconds, or less. 40 watt should be a good choice. Try several of the techniques suggested and see which one works best for you.
I use Ungar/Weller “Stained Glass” iron, in either 45 or 50 watt. 1000 degree tip temp, with good mass in the tip. I use the integral tip heating elements, not the “modular” tip that screws on the element. The screw on tips don’t have the heat transfer of the integral tips.
You can’t use a skinny little tip like you would use for circuit boards to do rail. Bigger spade or chisel tips work well for rail joints. More surface area for the tip to contact the rail with.
Try to avoid using long (or any) extension cords with a soldering iron. They seem to work hotter when you plug them straight into the socket.
I’ve been using TIX Solder from Micro Mark It melts at a very low temperature (for solder). Flux is required.
For me, the variable that takes me from frustration to good soldering is using a fine wire brush to clean the tip of the iron. If it’s getting crusty, the heat transfer is limited. Hardware stores sell brushes that look like toothbrushes only they have wood handles and brass bristles. They cost about a buck and one will keep your soldering tip clean for a long time. BTW, I brush it clean with the iron hot.
Soldering is a skill that comes easy to some folks and others struggle with it - everyone who perseveres learns to do it well. Keep trying and you’ll get it.
Along with a damp sponge, I use Radio Shack Tip Tinner / Cleaner Compound. It comes in a small container about the size of a silver dollar and has a self adhesive strip on the back. I use it frequently as I solder and it keeps the tip nice and shiny. The part number is 64/020 and last time I looked it cost around $7.00 for a container that will last years. It’s well worth it.
