Soldering

[gt40drver]

P1050519.JPG

Hi
I'm after advice on soldering code 75 track to copper clad.
What do you use, lead free, leaded and what temperature melting point.
Also which flux is good to use and what if any cleaning after to stop corrosion is needed.
I have made a point but have no clue what the solder is it has no marking apart from drapper
and the flux is powerflow. Done ok but the solder spreads quite a bit when I would like it more localised.
What is a good tip to use? I filed mine to a more chisel like point which helped.

Cheers.

[nigelcliffe]

Solder - I use leaded solder. The rules prohibiting lead solder are primarily for commercially produced electronics. The military and heath industries are exempt from the lead solder rules, which says something about it.

Why leaded ? - flow is better, temperature it melts is lower, easier to control. But some of that will be historic skills learned decades ago. Normal solder for most jobs is 60:40 lead tin mix, melts at 188 degrees C. That does most jobs, but if wanting a lower temperature to add detail, various options exist. Addition of a tiny quantity of silver makes solder flow thinner (but that's not hugely useful on track building). Carr's range of solder (from C&L Finescale these days) is a good range, and has (had?) good documentation on its use.


Iron - what matters is "power".
With a small low power iron, as soon as you touch the work, the heat is drained from the iron, and the element is incapable of putting in enough power to hold the temperature. To an extent, using a higher temperature low power iron can compensate for this draining of heat from the iron. This has more problems, the flux gets over-heated, the solder can misbehave, oxidise, and all sorts of issues arise. I think the "proper" solution is enough power. I use a 50W temperature controlled iron, with a variety of bit shapes to suit the job.

If you re-shape a soldering iron bit, then you have to consider how the bit was made. Some are iron-plated over copper. If you file through the iron plating, then the copper is exposed. This is OK, but the tip will erode fairly quickly, meaning more shaping is required, and it gets smaller each time ! I tend to only re-shape a tip for a special job, then restrict the use of that tip to the special jobs.


Flux .
Powerflo was developed for plumbing. Its good for plumbing. I'll be using it on a plumbing job tomorrow. It is very aggressive, and is designed to be cleaned up with a lot of water flowing through a pipe, or by wiping down the outside of a pipe after the job is done. In modelling it's fine provided you can completely clean the item after use; this means underwater scrubbing, or similar. Powerflo can also be cleaned with meths. If you leave Powerflo on a metal, it will corrode, and corrode quickly. Metal includes any tools near the flux !

With something like ply sleeper and rivets, dunking the wood sleepers in water isn't a good idea, so pick a different flux. Something less aggressive or easier to clean up. In many cases, old traditional Fluxite, or the flux within "cored" solder is completely adequate for track construction if the items are properly cleaned before attempting to join them.



- Nigel

[gt40drver]

Nigel
Thanks for the advice I have learnt quite a bit from your expertise.
I have a basic Maplin temp controlled iron but will probably upgrade at some point.
I shall give C and L a call tomorrow and get some stuff ordered.

Thanks Martin.

[dal-t]

For copper-clad construction I have always found that nothing performs quite like the solder included in SMP kits. Whether that is the result of careful research or fortunate happenstance, I have no idea. It is a cored solder (which we are normally advised to stay well away from for modelling work, stand fast electrical connections) but I liked the convenience of not needing separate flux. Of course the rail and sleepers must be freshly cleaned before fixing, but surely that should be standard practice anyway. The only drawback I found was that my eyes became sensitised to the fumes it gives off, and I had to consciously draw my head back before applying the iron. But then I was addicted for years to the construction of mixed-gauge track, which involved pretty close attention when building multiple-crossing formations. It's OK, I'm much better now ...

[gt40drver]

Thanks for that David I shall be trying different methods and materials I'm sure.
One question is their any difference between SMP and C & L code 75 bull head track for oo-sf.
I got some of each manufacturers flexible track and they vary quite a lot much preferred the C & L track
the sleepers were better detailed sand slightly stiffer. The SMP track came and the sleepers seemed to
be soft and many were bent up from level.
Martin.

[nigelcliffe]

For the fumes, build air extraction unit: nothing too sophisticated; a bit of flexible pipe, such as that used on a tumble dryer and a computer case ventilation fan to move the air. It only needs to draw the air away from the work area, so the fumes don't end up in your face. Computer case fans are usually fine on 12v DC from a model railway controller.

- Nigel

[Terry Bendall]

There are a few simple rules for soldering.

1 Get the metal clean. Even if it looks clean it will have an oxide coating. Rub it clean with a glass fibre brush or abrasive paper. I always use extra flux to keep the metal clean whilst soldering.

2 Make sure the parts to be joined fit closely together. Yes you can fill a gap with solder but a joint will be stronger if it is close fitting.

3 Get the metal hot enough. Lead free solders melt at around 230 degress C and some soldering irons won't get that hot. Tin/lead solder melts at around 188 degress C and some lower melting ones from C&L at about 155 degress C.

Fumes are only a major problem is you use solder with rosin in it and most solders do not contain rosin or if you have respiratory problems or are working in a confined space for a long period of time. In most instances opening a window is sufficient but some people may need a fume extractor and such things are available for around £45.

Terry Bendall

[David B]

I have just come back from a very enjoyable weekend at Missenden. I was shown Templar's Telux flux which is described as 'mild'. (Also available on Ebay.)

Has anyone used it? This is the first time I have heard of it, but the user, an experienced modeller, has used it in kit building for a long time. Apparently it is also gentle on your soldering iron bits.

[gt40drver]

Hi and thanks again for the replies. It's funny but that's the flux I have been using. Not sure where it came from
and I think it's years old but seems to do a good job. Not sure about the acidity of it though.
Martin.