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Soldering irons for fitting wires to decoders


Ruston
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Evening all,

 

I want to be able to solder wires for stay alives to, and to remove spare wires from, decoders but the thought of attempting this with the iron that I have for soldering brass kits puts me off even attempting it. Are there any irons that are recommended, preferably very short so they can be handled with the precision required to solder a wire on a decoder without destroying the decoder?

 

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Same as BH above - Antex with a small point tip.   I use a 50W temp-controlled version, but its about the same body size as the 18W.   The 25W may be another good option.  

 

What's more important is holding the decoder down (bluetac helps).   Having a heel rest (fat book, lump of wood) for your hand may help as well.  Arrange magnification if needed.  And have a practise on a scrap of PCB material.   

I manage solder size by cutting a tiny amount from some multi-core.  If its soldering to a new pad, I tin the pad first.  Then, strip the wire back a little,  tin the end of the wire, trim it back to just a little bit of tinned wire, then stick it to the decoder.   

 

 

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I use an Antex 15w iron with a 0.5mm tip. Ideal also for soldering SMD parts.

 

Whichever iron you use check to see if the tip is earthed. Some irons have a potential on the tip and can damage decoders.

 

 

C2074337-0033-443B-ABF9-85F8E72D061D.jpeg

Edited by RAF96
Add a picture of available tips...
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49 minutes ago, RAF96 said:

Whichever iron you use check to see if the tip is earthed. Some irons have a potential on the tip and can damage decoders.

 

The solution is not to solder stuff that is connected to different potential. A decoder on the bench will not be harmed by an unearthed soldering iron.

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5 hours ago, RAF96 said:

I use an Antex 15w iron with a 0.5mm tip. Ideal also for soldering SMD parts.

 

Whichever iron you use check to see if the tip is earthed. Some irons have a potential on the tip and can damage decoders.

What is the distance from the grip to the tip on the Antex 15w iron? What are SMD parts? I have absolutely no idea what the rest of that means.

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I don't know what make of iron you've got, but does it allow you to change tips and if so can you get a fine tip for it?  Preparing the work almost exactly as Nigel did (see his earlier posting) and using a 70w temperature controlled Hakko iron with a 1mm chisel-type tip I've just soldered the necessary wire (and rather neatly if I may say so) to a Zimo MX600 to allow for a stay-alive.  Unfortunately I now find that there isn't really room for the stay-alive in the loco.....

 

DT

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Torper's MX600 is a "tricky one", and not one I'd recommend for fitting stay-alives.   

 

I think worrying over the distance from handle to tip is the wrong way to think about things.  Better to support the hand with a raised block which stops any hand tremor.   

 

 

- Nigel

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1 hour ago, Nigelcliffe said:

Torper's MX600 is a "tricky one", and not one I'd recommend for fitting stay-alives.

  I followed the method illustrated by Vecchio in this thread (some way down the page)

It wasn't actually as difficult as I'd expected and it worked.  However, since then I've found a video from Digitrains that makes it even easier.  I haven't tried it but as It comes from Digitrains I have no reason to think that it won't work: https://www.youtube.com/watch?v=bOygyZJZR3A

 

DT

 

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14 hours ago, Ruston said:

What is the distance from the grip to the tip on the Antex 15w iron?

 

Perhaps these shots will assist. A new/spare Antex 15w I have along with the 'standard' fit wedge tip and in between a couple of the pointed 1mm tips. These are much smaller and easier to handle compared to even the Antex 18w let alone the 25w. You can see the size difference.

 

 

 

 

708512953_RMwebsolderingirons02.jpg.d21a6acae187f050559e95c8fe5570fc.jpg

 

1173021460_RMwebsolderingirons03.jpg.472373efcedb8317ea994b8861e2e604.jpg

 

907302725_RMwebsolderingirons04.jpg.f08a58ada02bba80597240bf8aa1d53a.jpg

 

761026548_RMwebsolderingirons01.jpg.5ccd2f392c2b65ddfb54b9a6508e1940.jpg

 

A 15w sits permanently on my workbench these days, I hardly ever use anything else at present hence the spare just in case. The rather larger Weller 75w is for O gauge work when push comes to shove..... I am not sure I would care to use it with decoders.....!

 

Interesting about the rear solder pad on the MX600. Zimo don't make any mention of this in their small decoder manual and it does seem an easier option.

 

Izzy

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The above photo is a good demonstration of an  issue with Draper and Weller irons (and others of such design) in that the tip fits inside the heated shank compared the Antex irons where the the tip slides over the heated shank. The effect of this is that a lot more of heat on an Antex iron has to heat the metal component of the tip whereas on the Weller a lot just disperses into the surrounding air. Now with a 70W iron that is not much of an issue other than an Antex iron of siightly less W probably works just as well but a Weller 15W iron I had, a not particularly wanted Christmas present, was a complete joke and took far longer than its Antex equivalent to melt solder.

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Just thought I would add these to illustrate why using the 1mm Antex tip is I think a good idea...

 

2019271252_RMwebTTSSA03.jpg.5d1db1c6c84e7ebd3c72baf58c325a53.jpg

 

365909094_RMwebTTSSA04.jpg.4a963d9c702ea149c58853cd68074a3b.jpg

 

I personally wouldn't want to try this malarky with a bigger one...!

 

Sorry, forgot.  SMD -surface mount device - soldered onto the pcb rather than through it via legs. You can see most pcb's use them these days.

 

Izzy

 

 

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Thanks, everyone. My iron looks rather like the blue one in Izzy's photo and is 4 inches from grip to tip, so I will get one of the small Antex irons, which appear to be almost half that length. With the 1mm tip I reckon I ought to be able to do it.

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1 hour ago, Richard Croft said:

There’s a much bigger pad along the edge of the black circle which you can solder the negative to which has been mentioned elsewhere on the forum, you can get away with a bigger, more multi purpose tip then


Yes, sorry Richard, and thanks, it was my thread :D and I just used a couple of the shots to show the tip size. Good to point it out though. The problem is I use a lot of smaller decoders than the TTS, some of which have stupidly small - or non existent - solder pads which require a bit of wrangling to deal with, come on down CT....and the smaller the tip the easier it becomes - usually!

 

cheers

 

Izzy

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I have been using one of these for a few years now when doing work on decoders, replacing wires or adding stay alive wires

 

https://www.ebay.co.uk/itm/283575730671

 

Only 8 watts but a super fine tip and more than enough heat for thin leaded solder 0.3 or 0.5mm 

 

Not enough mass for large ground connection but more than enough for the pads on decoders.

 

Don't knock them until you have tried them, good enough for big Clive they are good enough for Me ;)

 

NGM

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I think there's a little misunderstanding by some on the subject of wattage.  Set to, say, 400 degrees, my 70w iron won't get any hotter than a 15W iron set to the same temperature.  What it will do is have plenty of power in reserve and will maintain a relatively constant soldering temperature even while it is being used.  A low wattage iron can lose heat faster than it can reheat itself and the result will be either a bad joint or no joint at all.  With a higher wattage iron, there will be no such temperature loss and the tip will retain its heat throughout the job.

 

There's therefore no real sense in choosing a low wattage iron to do small jobs.  With a similarly sized tip a high wattage iron will be no hotter but will retain the heat much better.  It will also of course cope with larger tasks that would be beyond a low wattage iron.

 

DT

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12 hours ago, Torper said:

I think there's a little misunderstanding by some on the subject of wattage.  Set to, say, 400 degrees, my 70w iron won't get any hotter than a 15W iron set to the same temperature.  What it will do is have plenty of power in reserve and will maintain a relatively constant soldering temperature even while it is being used.  A low wattage iron can lose heat faster than it can reheat itself and the result will be either a bad joint or no joint at all.  With a higher wattage iron, there will be no such temperature loss and the tip will retain its heat throughout the job.

 

There's therefore no real sense in choosing a low wattage iron to do small jobs.  With a similarly sized tip a high wattage iron will be no hotter but will retain the heat much better.  It will also of course cope with larger tasks that would be beyond a low wattage iron.

 

DT

 

Everyone should print this out, laminate it and stick it to their workshop wall :)

 

Edited by Crosland
grammar
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