what cable for soldering to track?

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Dale_the_noob
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what cable for soldering to track?

Postby Dale_the_noob » Sun Dec 12, 2010 10:39 pm

I had a go at soldering cable to the track today (n gauge) and on my 4th try I had much better results, just ordered a fiberglass rubber and 3rd hand thingy. I've got some flux from doing plumbing. I gather flux is flux and I just need to use a small applicator to apply to the rail.

What sort of cable should I use? Solid or multi strand? What sort of ampage? Would 1A be ok for between track and bus wire?

Also what size cable for the bus wire?

Thanks in advance.

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Roger (RJ)
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Re: what cable for soldering to track?

Postby Roger (RJ) » Sun Dec 12, 2010 11:14 pm

Don't use plumbing flux. It's not the right thing to use.

You need proper electrical solder that contains its own flux.

You can get electrical solder from ebay, such as this or this or from suppliers such as Maplins, although the solder that Maplins now sell is the lead free variety (see * below)

Plumbers flux needs to be washed off after use, the flux in electrical solder is none corrosive and doesn't need cleaning off.

* I would advise you to avoid the newer lead free solder as it is slightly more difficult to use than the traditional lead/tin solder.

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Re: what cable for soldering to track?

Postby m8internet » Sun Dec 12, 2010 11:14 pm

DC or DCC?

In DCC I am using 7/0.2 wire for the droppers, in lengths of 100mm, as it will have short bursts of up 2A and typically up to 0.5A
The bus wire is 32/0.2 wire, as it has to cope with up to 5A

I am managing without any specialist tools
Solder is applied to the wire
Solder is then applied to the accepting media (rail, wire, etc)
The wire is then held to the accepting media, the soldering iron to that, the whole lot melts and the soldering iron is removed; solder complete
Last edited by m8internet on Mon Dec 13, 2010 2:56 pm, edited 1 time in total.
Glasgow Queen Street Model Railway layout : modern image N gauge using DCC

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Dale_the_noob
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Re: what cable for soldering to track?

Postby Dale_the_noob » Sun Dec 12, 2010 11:19 pm

I've read on various topics to use flux to help clean the rail and help the solder spread evenly

My main problem tonight was trying to get the solder on the rail.

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Roger (RJ)
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Re: what cable for soldering to track?

Postby Roger (RJ) » Sun Dec 12, 2010 11:29 pm

If the rails are dirty, clean the area to be soldered with something abrasive such as a fibreglass brush, emery or sandpaper or a fine file. You don't need to use a separate flux to solder to nickel silver track but it may well be needed for steel track, in which case, use a proper flux designed for electrical work.
Acidic plumbers flux needs to be washed off to prevent corrosion and it's obviously not practical to wash track and wiring with water.

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Peterm
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Re: what cable for soldering to track?

Postby Peterm » Wed Dec 15, 2010 12:27 am

You'll also find that plumbers type flux will travel up inside the wire insulation and carries on eating away, even if you could wash the track after soldering.

All I do is use a small (jewellers) screwdriver to scratch the side of the rail, then as M8 has said, tin the track, using a hot iron (I use 350 degrees) with a cored solder (put a drop of solder on the tip, touch the tip to the rail, when it's all hot, touch the solder to the rail so that the solder runs to the point you want it, and it's done.) Do the same with the wire, bending the end of the tinned wire at 90 degrees. Once again, put a small drop of solder on the tip, hold the wire to the spot you want it along with the tip and it should all run together. Don't hang about with the iron, as you'll melt sleepers if you do. One more thing: you should use an iron with enough power to heat the rail up quickly, which is why I use a good quality iron and run it at 350 degrees. It never fails.
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Re: what cable for soldering to track?

Postby b308 » Wed Dec 15, 2010 9:18 am

I don't know what size iron you are using but a 15w is about best... The cheapo ones you can get for a fiver are about 25/30w and are really too big for wiring as you are likely to melt the plastic sleepres as well!

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Dale_the_noob
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Re: what cable for soldering to track?

Postby Dale_the_noob » Wed Dec 15, 2010 11:58 am

I've got an 18 watt jobbie with a small pointed tip (soldering n gauge) and either the iron isn't getting hot enough of the tip is very poor at transferring the heat to the rail.

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Re: what cable for soldering to track?

Postby RFS » Wed Dec 15, 2010 1:50 pm

I found a small, pointed tip useless for soldering dropper wires to the rails. I changed to an Antex 25-watt iron with a chisel-shaped 2.3mm tip and this works very well indeed.
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Re: what cable for soldering to track?

Postby b308 » Wed Dec 15, 2010 2:13 pm

I use N gauge track and would say that a 25w iron is too big, you are more likely to melt the plastic sleepers! I'd agree re the tip, a small chisel head for that iron you have will be ok. A 25w iron is fine for assembling a brass kit, but for soldering thin wires to track you don't need anything big, the one you have is ok, but as said you are not transferring enough heat with a pointed head!

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Peterm
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Re: what cable for soldering to track?

Postby Peterm » Thu Dec 16, 2010 12:14 am

Well I stand by what I said earlier, that is that you need an iron with enough power to heat the rail quickly; this is what prevents you melting sleepers. If your iron is underpowered you have to keep it on the rail longer which is what does the damage. My iron is a temp' controlled 60 watt, and I can solder a dropper to a rail in very short order. No melted sleepers and a good join every time. This is because the iron heats the rail quickly thus keeping the heat localised, rather than spreading it around from holding the tip on for too long.
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Re: what cable for soldering to track?

Postby b308 » Thu Dec 16, 2010 10:23 am

He asked for opinions and thats what we've given. A larger iron will work if used skilfully, but it carries more danger of melting bits in unskilled hands. I remember having this conversation with a chap at work who was having the same problem, however he was using a 25w iron and melting everything. Since he has transferred to a smaller one its been ok... but he had a chisel head on the smaller one, which transfers more heat than a pin head one... which is where the OPs problem is?

Its up to you, Dale, I'd suggest you try changing the head on the iron you have as that is initially the cheapest option, however if that doesn't work then by all means try the larger irons.

Of course there is another option to prevent melted sleepers and that is to slide the sleeper base away from the bit of rail you are soldering which will reduce the chance of ruined sleepers and give you the chance to ensure everything is clean! As m8 said "tin" both bits to be joined, then its only a question of a brief touch with the iron to join them Re wire, I use multi core wire, not the "bell wire" stuff... There's always a chance when using single core that it will break if bent too far and will be a sod to replace... Good Luck! :wink:

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Bufferstop
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Re: what cable for soldering to track?

Postby Bufferstop » Thu Dec 16, 2010 12:09 pm

It's not just the wattage and tip size/shape, there's also the thermal capacity of the iron. Many small 15w irons have virtually no mass in the body so the heat in the tip is coming directly from the element. If there is sufficient metal in the body of the iron it will be much slower to heat up but its temperature will not fall noticeably when it comes into contact with the rail. I'm still using an unbranded 15W 12V industrial jobie that's all but indestructible. It has a chisel tip which just fits into the web of code 75, solder touched against the rail alongside the iron flows almost immediately. I have a lightweight 15W mains iron which is useless on rail.
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Peterm
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Re: what cable for soldering to track?

Postby Peterm » Thu Dec 16, 2010 10:28 pm

Now listen 'ere b308... don't make assertions that I'm skilful ! The only thing I'm much good at nowadays is falling over.
Pete.

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Dale_the_noob
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Re: what cable for soldering to track?

Postby Dale_the_noob » Fri Dec 17, 2010 9:25 am

I've just ordered a 2.3mm tip for the iron, so I will see how I go with that.

In the meantime, 2 'extra hand' holding thingys have arrived and a fibreglass pen for cleaning the rail have arrived.

Hopefully I will have a much more successful sodlering session next week.

Thanks for the tips.

btw I'd go for the more powerful iron than the holding a less powerful iron still for longer between sleepers.

I'll see how it goes with the new tip and get back to you.


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