Without power to the track, then everything is a bit pointless, pardon the pun. There are a few different ways of linking your controller (digital or analogue) to the track, so let us explore some of them.
With a starter set a power feed clip or plug is usually provided, but as expansion takes place more feeds may be required. More power clips can of course be added, but there are alternatives; Gaugemaster provide rail joiners with wires attached for both N (GM17) and OO (GM13) scales – as do Peco for various track sizes.
If multiple feeds are required it maybe worth considering soldering wires directly to the track - especially if the track is already laid - to save ripping up the track in order to add a forgotten feed. "Ah", you might say, "I don’t know how to solder". This is where I’m here to help! The principle of soldering is actually quite simple, there are no dark arts associated with it, and once mastered is never forgotten.
The first thing to point out is that Soldering Irons get HOT, and can cause a nasty burn; either to skin, or tables, or carpets, etc. So, when soldering, do not leave the iron unattended, especially if children are around. Remember, just because an iron doesn’t look hot, it takes a while to cool down when switched off. Safety First!
Next, is to obtain the right tools for the job, namely wire cutters and wire strippers, something to clean the rails with, a good quality soldering iron and stand, and of course, the right size wire and solder.
A lot of folk, when choosing an iron, are of the opinion that you don’t want it to be too powerful an iron as this will melt the sleepers - but this is a misconception. A 15-watt iron will take too long to heat up the spot where the wire has to go, causing the heat to travel along the rails. Because the melting point of plastic is lower, than the melting point of normal solder, the heat may start to melt the sleepers or railchairs. Whereas, a 25-watt, or above, will heat up the section of rail quickly, allowing the solder to melt rapidly, before the heat can travel too far along the track.
First and foremost, cleanliness is of the essence as solder will not bond to dirt, grime, or oily surfaces. So, having decided where you want to attach a wire, clean the outside edge of the rail, using a glass fibre pen (GM635) or, if the rail is oily, a detergent mix on a cotton bud. Then we are ready.
Another thing to consider is keeping the tip of the iron clean. Otherwise, you will find that over time the flux, in ready fluxed solders, or plain flux will attack the tip; gradually corroding it and making it useless.
Most good soldering iron stands are supplied with a sponge which you keep damp, enabling you to wipe the tip of the iron every so often. This will prolong the life of the tip - my current tip is about 9 years old now, and still going strong.
So, what next?
Having decided where we want to put the track feed, we do, what is called, tinning on both the rail and the wire.
Tinning means adding the solder to both parts that need to be joined and this is done by applying the iron to the rail, adding the solder to a small area of the rail, then adding a small amount of solder to the wire.
We can then place the wire in position. Then, using the iron again, heat up both until the solder melts, bonding the two parts together. Whilst removing the iron, give a quick blow to help cooling, and the job is done.
I usually give the wire a gentle tug to make sure everything is firmly attached. I then clean the upper surface of the rail, in case any flux has made its way onto the running surface, and I also check that the wire, or solder, is not stuck up to derail passing rolling stock. Then on to the next job.
Now is also a good time to check that the joint is a good one, by checking with a meter for continuity from the end of the wire to the rail. Once the joint has cooled down, it is also a good idea to check whether the joint is a shiny silver colour. If it is dull and grey looking, this is a sign of what is called a dry joint, caused when the flux has remained in the solder, which may cause the joint to be non-conductive, i.e. not passing current. If this is the case, reapplying the iron for a short period usually cures this.
So, there we are! The best way to learn this technique is to practice on scrap bits of rail first, before attempting to add feeds to your actual layout. If you damage a piece of scrap rail, it doesn’t matter half as much as damaging a piece of rail in the middle of a complex junction!