Soldering Chips and Stay Alives on small decoders

[RedgateModels]

The problem with fine pointed tips is they have very small thermal mass at the very end, so heat soak even on a small joint is high. You really need a much higher wattage iron to use a very fine tip so that the heat can be maintained. 

 

I too favour a small chisel ended bit with my little 15w Antex.

[Nigelcliffe]

4 minutes ago, RedgateModels said:

The problem with fine pointed tips is they have very small thermal mass at the very end, so heat soak even on a small joint is high. You really need a much higher wattage iron to use a very fine tip so that the heat can be maintained. 

 

Which is where the 50W temp-controlled Antex I mentioned near the top of the thread comes in.   It is an expensive piece of equipment.  It has a small light hand piece (like the 18W mains iron) and a lot of energy behind it to keep the tip temperature constant, and that constant temp can be whatever is dialled into the base unit. 

 

 

[woodenhead]

2 hours ago, peterm1 said:

I have the same problem with pointed tips. They don't like to pick up the solder. I always use a chisel shaped tip of about 2.5 or 3mm

 

I was struggling for ages with the pointy bit - even it's sides would not melt the solder quickly, swapped to the chisel shaped on and voila fast melting.

 

I am going to take that to be that pointy or round bits have a smaller surface area touching the solder which massively slows down the heat transfer, whereas the chisel imparts a much greater area of heat which quickly transfers to the solder.

 

First science lesson I've had in years!

 

I think I might have to flatten one side of the pointy bit to give it a chisel edge as it's size was brilliant for the solder pad.

[Izzy]

1 hour ago, woodenhead said:

 

I think I might have to flatten one side of the pointy bit to give it a chisel edge as it's size was brilliant for the solder pad.

This is what I do, file a small flat at about 45/60 degrees on the very end. Roughly 1mm max diameter. I think I mentioned it in a previous post in passing. It’s all a bit trial and error. Soldering seems to be one of those aspects where everybody finds a method that suits them that often differs to others. 
 

Bob

[woodenhead]

On 23/08/2023 at 02:07, dpgibbons said:

Where there is room, I much prefer to use a plug-in decoder with a breakout board. These have nice big solder pads for connections thereby removing the need to solder on the decoder.

N Gauge and very little room - luckily with the DMUs I can relocate the speaker from the end into the seating utilising the speaker space for the stay alive provided I remember the worm is exposed at that end and not to use black tack to hold said stay alive in situ - kapton tape in future.

 

I'd rather not be filing down loco chassis to make space, so far on older locos I've simply removed the cab interior and used that space for speakers, I can use the other end for the stay alives I guess.  The issue might come on my Warship and Western because of the volumous cabs on the real thing, great for space for stuff but I am thinking it will also be so much more obvious than on other locos that I've removed the interior for electronics.

 

Coming back to soldering, in the past all I've needed to worry about is wiring track or switches, the size of the bit was not really an issue though I am now realising that my old bit also being pointy was probably also not transferring heat as efficiently as it could have done making the job harder.  Perhaps if I had been braver earlier with DCC and gotten on with learning about hard wiring etc I would have learnt more about the dark art of fine soldering, better late than never I guess.

 

Ultimately what I am finding is that each locomotive or unit targeted for a Stay Alive performs oh so much better after the procedure and my enjoyment of playing with the trains goes up.  I am finding myself shunting in N, something that I used to find a lot more frustrating than now with a stay alive fitted 08.

 

Something is clearly changing in my mindset, the usual barriers to enjoyment, the usual point where I give up - they being surpassed and I am moving forwards rather than starting over.  Maybe the overall roof I so desire for the station is not pie in the sky and I will actually build it.

[Steven B]

On 15/08/2023 at 13:56, Luke Piewalker said:

I recommend trying to get one with a silicon power lead rather than PVC. Much more flexible straight out the box.

 

The silicon power leads also have the advantage that they're more heat-resistant than the PVC version.

 

90% of my soldering is done with an Antex CS18 that I've had since 1995 (with one replacement element fitted three years ago). Otherwise I use an Antex temperature controlled soldering station.

 

Antex produce chisel bits with 0.5 and 1mm (1105 and 1106) - there should be no need to file bits.

 

 

Steven B.

[woodenhead]

15 minutes ago, Steven B said:

 

Antex produce chisel bits with 0.5 and 1mm (1105 and 1106) - there should be no need to file bits.

Except when you've just bought some pointy tips and learnt the hard way that chisel tips are better. 🙁

 

They're not expensive so I might as well get a file out rather than waste them before paying more postage on more tips.

 

Which reminds me, I need to order some more stay alives....

[Lemmy282]

It really comes down to preference and practice. I use pointy bits for electronic kit and chip soldering, but it is a 50w iron, so it keeps the temperature high enough all the time. If chisel bits work for you, stick with it!

[woodenhead]

Joy - the MS500 sound chips on my Sulzers come ready wired for a Stay Alive - I just need to solder directly to the Lais Stay Alive - much less problematic and tells me later sound jobs on a 37 and 47 will be less stressful on me.

 

A quick test fit indicated it will fit into the cab space especially if I replace the plastic shrink wrap with kapton tape (I need to remove the shrink wrap to solder the wires).

[Crosland]

Filing destroys any coating and just leads to the bits corroding away. You end up re-filing until there's nothing left.

[Carnforth]

1 minute ago, Crosland said:

Filing destroys any coating and just leads to the bits corroding away. You end up re-filing until there's nothing left.

Agreed, once you've removed the iron coating on Antex bits, they're on a short lifespan.

[woodenhead]

On 26/08/2023 at 15:09, Crosland said:

Filing destroys any coating and just leads to the bits corroding away. You end up re-filing until there's nothing left.

The smallest point I have doesn't even have the coating!  I got it more for the experiment about how well it might work, not very well as I found out.  If it doesn't last long, well that's fine I don't do a lot of soldering.  The other two that are tinned are unopened, I may return them for a refund and got a small chiselled head in replacement.

 

I was just soldering an MS500 to a Lais stay alive for my 25, with the standard as supplied chisel headed bit it was fine, melted in a second and very quick to complete the job.

 

I've learned something this week when it comes to soldering so I see it as a good thing, and now I have a third engine fitted with a stay alive.

 

But boy it was a squeeze getting the body back on and still keeping the red light prism in place (Farish 25/1), glad I don't regularly need to remove it.

[woodenhead]

Tonight I came back to the reason I began this thread - a fried chip after attempting to solder with an old iron.

 

I purchased the new chip a month back but waited until Stafford to pick up more Lais Stay Alives and also a pack of Tantalums.

 

Whilst I had planned to install a Lais in a wagon I kind of preferred to keep it all in the loco if I could and the Tantalum being a fraction of the size of the Lais offered a potential solution.  Ok one Tantalum is a fraction of the power, but I am not needing much, just a little push here and there, mainly on the station throat.

 

Step one was add common return wire to the smallest chip Zimo offer with the tiniest little solder pads - with the new iron (with a chiselled end) I got the solder on cleanly and quickly - hardest part done 🙂

 

Then it was off with the old chip on the loco, on with the new plus added Tantalum and hey presto, one working 04.  In the video it does momentarily stick on the point and I did go back and clean the track afterwards and try again where it was fine.  Stay Alives are not an excuse for dirty track and the single Tantalum is not going to break records in power performance, but I think it is helping.  I am pleased the loco is back together, I've managed to do a very delicate piece of soldering  and my new found desire to find solutions instead of giving up is paying off.

 

 

 

 

Earlier I also added a Lais to another DMU, this time the speaker stayed at the back and the Lais went into the vestibule, the MX490 has much better soldering pads to aim at.

 

 

 

I'll use the three spare Tantalums I now have on the remaing class 25 and the two class 24s, the Lais left very little room to get the body back on without causing the lighting prisms to pop out, the Tantalum should leave a lot more space and these locos are already very good runners so don't need much help.