cold wire glue/paste

[stevieedge]

Hi 

I am using dcc and have a large number of power supply joints to make to the track. My soldering is not very good so I tried wire glue (carbon based) I have used a meter accros the conection and I think its reading 25ohms (approx 2.5 on the x10 scale) The joint seems well fixed but will this (resistance ? There is a power supply joint say every 3 to 4  feet) make any noticeable difference to running trains? I have only done the one joint to test so far.

[walkingthedog]

If glue was any good it would be used by many of us. Nothing is a substitute for soldering apart from screw connections or perhaps the correct size scotchlocks. 

 

Practice your soldering, it is difficult to run a model railway without it. 

[Chrissaf]

25 ohms might not seem very much, but in electrical power terms that is a very high resistance.

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• Pass a current through a resistance and heat is generated.
• The Ohm's Law formula for power (Watts) is Current x Current x Resistance.
• So let's say you are passing 250mA (1/4 Amp) through your glued 25 Ohm joint.
• The Watts would equal 0.25 x 0.25 x 25 = 1.6 Watts, doesn't sound much does it. But you would be unable to hold a finger on that joint without burning yourself.
• That is a lot of Watts (Heat) to dissipate in what should be a totally cold joint.
• The likelihood is that the glue will fail due to that level of heat.

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In addition to the above, unlike DC Analogue....Digital DCC is extremely sensitive to excess resistance in the power delivery path.

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Take my advice do not even contemplate using glued electrical joints as an alternative on anything, let alone model railways.

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These 'Electrical Glues' are just not designed for the type of electrical work you are contemplating. The are designed for undertaking small repairs on things like circuit boards where the currents being passed through the glue are miniscule, and thus the heats generated are miniscule as well.

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Have a read of my 'Soldering Tutorial'. Soldering wires to modern Nickle Silver rails has got to be one of the easiest soldering tasks you will ever undertake providing you use the right tools for the job and follow good guidance. My tutorial should assist you in doing that.

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[walkingthedog]

Or even my advice and practice your soldering, well worthwhile.

[EnGee]

I have just read Chrissaf's excellent tutorial but it seems to missing the first page! There are a few things to bare in mind before you go anywhere near a soldering iron.

 

 

Firstly you have to remember that soldering was invented by an octopus!!

 

 

You need one hand to hold whatever you're trying to solder and one hand to hold whatever you're trying to solder it to. You're also going to need one hand to hold the solder and one hand to hold the soldering iron and if you're going to add extra flux that'll need another hand not to mention the one that you might need to adjust anything slightly while doing the joint. Unfortunately, as mere humans, we only have 2 hands, and that is what causes the most problems for beginners. So we're going to need some extra helping hands!

 

 

Check out 'Helping Hands', these can be bought for less than a fiver on Ebay or the local market. Buy a couple and fix them to a piece of plywood (mine is about 18” x 9” but size isn't important).

You can also drill a few holes in it and fit lengths of flexible wire with a crocodile clip on the end of each one. (I use about 6” of one core of 30 amp (cooker) cable). Screw a couple of Bulldog clips to it as these are good for holding circuit boards, although be careful not to damage the board and if necessary, wrap the board in some soft material. Bulldog clips and crocodile clips come in several different sizes and can all be fitted to your own requirements.

Blue Tack is also very useful for holding things in the right place, especially good for holding components onto circuit boards while being soldered.

 

 

Obviously this idea works better in a workshop but even a short length of wood with just 2 croc clips can make soldering anywhere around the layout so much easier.

 

 

However you do it, the object is to get the 2 pieces you want to solder held steady in the correct place before you try to join them together.

 

 

So - Make up your soldering jig - clean and tin the 2 parts you want to join, as per Chrissaf's excellent tutorial - fix the 2 parts in the jig so as they are touching and steady.

Now you only need one hand to apply the soldering iron to the joint, maybe two hands if you need a bit more solder!

 

 

Hope this helps, but as others have said, practise makes perfect!

 

[walkingthedog]

If you are soldering wire to the track, tin the wire, tin the track, touch wire to track, touch soldering iron to wire/track. Only two hands required.  😆

[96RAF]

I only have two hands and I have managed to solder quite well. Admittedly I do use a pair of those helping hands but thats mainly so I can avoid melting plastic parts with the iron whilst juggling the wires and solder, etc.

[EnGee]

If you are soldering wire to the track, tin the wire, tin the track, touch wire to track, touch soldering iron to wire/track. Only two hands required.  😆

Yes, until the wire you are holding gets too hot, you drop it and you're right back to square one!!

 

However I do agree that if you are used to soldering then joining wires to the track can be fairly easily done without a jig.

 

My post was written to help and encourage newcomers who are afraid of soldering and, although I know this thread was specifically about joining wires to track, it was written as a preamble to Chrissaf's post about soldering in general!!

[walkingthedog]

When I did my GPO Telephones apprenticeship I soldered tens of thousands of wires and don't recall burning my fingers on hot wires. Did get hold of the wrong end of an iron once...........only once.  😉

 

You hold the wire against the track with the end of a wooden coffee stirrer. 

[LCDR]

Soldering is an art which can be learned quickly. 

[walkingthedog]

Next thing I'd like to do is learn to weld properly. 

[Chrissaf]

Yes, until the wire you are holding gets too hot, you drop it and you're right back to square one!!

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That only happens in one of two situations.

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1. The iron is too big and too hot for the task in hand or has a dirty bit. The bit should shine with fresh tinning just like chrome.
2. You are holding the iron on the joint for too long, probably because the contact surfaces have not been properly prepared. Not enough tinning, or too dirty or a combination of both.

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[Puffed Out]

I soldered some track for the first time. I bought cored solder, and a small pot of soldering flux.

1). Put a tiny bit of soldering flux on all the ends, including the fish plates) of the rails to be joined.(One at a time)

2). Clean the point of the soldering iron with some fine emery cloth, and dip the end in the flux, when it's hot.

3). Make sure your fine point electric soldering is at it's hottest.

4). Push the rails together.

5). Hold the iron on the joint.

6). Dip your solder in the flux, and touch the soldering iron when the flux in the joint starts to sizzle.

7). DO NOT add too much solder.(you can always add a touch more later).

8). Wipe of excess flux, and clean the rail joints.

...

The solder will run inside the fishplates, as well to the end of the rails. The rails I used were tarnished, and almost beyond saving. Used then on my sidings.  I tried to pull my first soldered tracks apart, and ruined/broke the track.  So my soldering worked extremely well.

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[joe_holmes1]

Chrissaf

 

I have found your tutorial really easy to follow and to learn from.

My initial attempts were to say the least dreadful.

However, since I printed off your tutorial and now follow it each time I attempt to do a little bit of soldering, I find that it is becoming better each time.

So thank you for your guidance on this subject, it is a great help.

😀

[Chrissaf]

Practice is all it takes....plus the right tools for the job of course.

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Liberal use of the right kind of Flux can usually mask the effects of other errors. For example if not spotlessly clean, Flux can etch through the dirt and let the solder flow.

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The key thing for a newbie is NOT to use 'lead free' solder. 60/40 multi-core solder is ideal to learn with as it is very forgiving with regard the soldering methodology and technique used.

[Puffed Out]

This is what I uses for a soldering iron.  I never bought it from Fleaby though.

 

https://www.ebay.co.uk/itm/Dekton-30-watt-Professional-soldering-iron-Light-Weight-Welding-Welder-REDUCED/283658791967?epid=1052143291&hash=item420b61ac1f:g:-nIAAOSwRn1cO1LD

[Chrissaf]

In my opinion @ 30 Watts that iron is far too powerful for delicate model railway work.

[walkingthedog]

I use a variable temperature 60 watt soldering station. Works for just about everything.

[Puffed Out]

@Chrissaf.

The less powerful the longer you have to leave it on, i.m.o.a.

Leaving it on longer would possibly melt the rail sleepers.  The tip of the soldering iron is focussed in a small area.  As for other jobs for modelling, I haven't tried.

I guess, it's each to their own. 😆

[Chrissaf]

I've used a 15 watt iron for ALL my railway work and never had to leave the iron on the joint more than 1 or 2 seconds at most, even when soldering wires to rails (Nickle Silver rails that is). It's all in the preparation and technique. I say again, that if the iron is held on long enough to melt the plastic then it is not being done with the optimum methodology. Now steel rails, that is a different matter entirely.

[96RAF]

Next thing I'd like to do is learn to weld properly. 

 

I did welding as my month long resettlement course when I left the RAF in ‘84. Gas, stick, mig and tig, with an insight into specialist techniques like welding rails and girders, underwater, various fusion techniques, etc. Fun part was trying to weld a magnesium gearbox casing without setting it on fire. Not long enough time to learn deep skills but enough knowledge imparted to be able to practice towards reasonable competence. Handy skills to have.

 

Much like soldering - basic stick welding is about good prep, the right current setting and the right size rods of the correct material mix for the job.

[Puffed Out]

Back in my old College days as a Plumber and Pipe Fitter, we had to join Lead to Copper, Iron, Mild Steel, and even Cast Iron.  The methods involved were a challenge, from Solder Wiping to Silver Soldering and welding and Braising.  Apart from having to look good, they were pressure tested to see of they failed, or not.

Copper piping was a doddle to join. Then the advent of solder was added to the Flux, hence 'Solder Paste'........easy peasey, especially for 'Tinning'.

Like you @Community Moderator, some of what we learnt can be applied to so many job/hobby/work applications.

[96RAF]

One of my apprentice test jobs was to build the Eiffel Tower from piano wire soldered together in sections. Obviously different melting point solders had to be used to avoid step 2 or 3 dismantling step 1 or 2 or worse as you progressed to the putting the last bit on the top.

 

Another test job was to file a 1” cube from brass to fit every which way with appropriate tolerance through a 1” square hole in a piece of steel sheet (not granite per the Tribute). The test job is imortalised at RAF Halton.

 

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You do not drop those standards In later life.