Soldering Irons/torches

[big-ted]

With the rainy weather arriving in earnest, I'm looking to spend more time indoors building train bits. Having played around with wood and laser cutting, I'm now going to try my hand at a bit of basic sheet metal work, starting with some tinplate creations, for which an iron 'in the 40 to 60W range' is recommended.

I'd eventually like to graduate to brass and heavier duty models, for which most seem to use a torch.

Either way, my little 25W electrical iron isn't going to cut it, so I'm shopping for something new. Is it possible to get something that will do both tinplate and brass, or is this really a case of needing the right tool for each job?

Any advice appreciated!

[dewintondave]

I use an 80W iron for both. Sometimes I do some preheating with a blowtorch on heavy sections.

Best wishes
Dave

[Big Jim]

I tend to use a micro torch for most of my work with along with a temp controlled 60w one for detailing stuff. With thin metals such as tinplate heat distortion can be a real problem.

a decent solder and a decent flux make all the difference.

[big-ted]

Hmm. Temperature-controlled irons are considerably more than the combined cost of a 60W iron and a small torch. Sounds like two separate tools is the way to go! Many thanks!

[dizzysteamer]

Hmm. Temperature-controlled irons are considerably more than the combined cost of a 60W iron and a small torch. Sounds like two separate tools is the way to go! Many thanks!

I can highly recommend a good quality temp controlled iron with a large bit i use a 120 watt for leaded glass work it is perfect for sheet metal work and can even solder heavy electrical connections I also use a hot air gun for soft soldering sheet brass.
With the knowledge gained If i could only have one item it would be this iron followed by a medium blow torch of about 4 to 5 kw and you will be able to do 99% of your work with these.

dizzysteamer  :D

[ge_rik]

I tend to use a micro torch for most of my work with along with a temp controlled 60w one for detailing stuff. With thin metals such as tinplate heat distortion can be a real problem.

a decent solder and a decent flux make all the difference.

Any tips on how to avoid distortion would be appreciated by me. I'm intending to embark on putting together my very first brass etch kit of a Donegal railcar and there is a daunting number of parts on three large sheets of brass. Jonathan from G-Bits has supplied me with a suitable motor block contained in a swear-box which he's suggested I return when full.

Rik

[dizzysteamer]

I tend to use a micro torch for most of my work with along with a temp controlled 60w one for detailing stuff. With thin metals such as tinplate heat distortion can be a real problem.

a decent solder and a decent flux make all the difference.

Any tips on how to avoid distortion would be appreciated by me. I'm intending to embark on putting together my very first brass etch kit of a Donegal railcar and there is a daunting number of parts on three large sheets of brass. Jonathan from G-Bits has supplied me with a suitable motor block contained in a swear-box which he's suggested I return when full.

Rik

Hi Rik I seen these kits on you tube not had anything to do with them but when working with a largish sheet of brass or silver I always work on a reflective ceramic or fire brick or a kiln shelf if you can get one.

You have two ways to approach a largish sheet either isolate the most part with a large heat sink go in quick with a very hot iron and out super quick.

Or gently heat the whole thing in a uniform way, that way the whole sheet will get hot with no distortion then just concentrate the iron on the part you want to solder. I use a hot air gun for this uniform heating. I often place items in a domestic oven or my kiln at a low setting always heat slowly. No need to over heat either.

I also use a really nice stuff that is really useful for some jobs where you don't want to unsolder something yet need to solder something close to it.
It's called Thermo-gel A 5 to 10 mm thickness will protect anything even from red heat I use it when silver soldering. But works well for cases were u forgot to do things in order.

The other thing to remember is to keep things clean very clean, do the large parts first lots of heat applied can make small items drop off again.
Don't overheat its better to come up to temp than oxidize the surface then have to clean it again.
When the temperature is right solder will flow like liquid paraffin it follows the highest heat unless its over hot.

Practice first on off cuts always do this it gets you in the right frame of mind.

If working with soft solder on parts where you don't want solder to flow paste the area with correction fluid it prevents solder sticking its messy to clean though.

If you prefer two stage soldering for large parts i.e. no worries for overheating one part already soldered whilst doing a second part you could buy some com sol solder this has a higher temp melting point than 60/40 normal solder electrical engineers use. It's for commutators on motors so a lot higher melting point.
Likewise you can also buy eutectic 63/37 solder which as a very low melting point far lower than 60/40 I use it to decorate items like glass box's which are already soldered.

Lastly I use Bakers fluid not these fancy flux's or the type for plumbers they use unleaded solder for plumbing its not formulated correctly for leaded solder it works but leaves a residue which is hard to remove, it looks clean but eventually will bleed through paint again.

Bakers fliud and a small brush is a pure pleasure to work with clean and very effective if u do find a small issue a simple brush of the fluid across the problem will see the solder flow through cleanly.
I suspect some people will disagree but some fluxes are really nasty to use don't forget to pre tin if its a load bearing part however for small parts and fittings there is no need if fluxed with bakers fluid the solder will wick through even the smallest clearance providing its heated correctly.
Hope this helps a little. but practice first every time you do a session it really does help to get it right nearly everybody over solder's joints this is a waste and a real pain to clean off apart from looks rather amateurish practice and you will be surprised in your own skills I have taught literally hundreds of people to solder from very young to my own age and beyond
I suspect before your half way through your build you will be amazed at your own results
If you have any queries please feel free to PM me
I wish you every success

Regards dizzysteamer

[ge_rik]

Thanks for the comprehensive reply. Looks like some really useful advice here. I'll try tracking down some Bakers' fluid. I only have paste flux at present.

Rik

[big-ted]

Thanks for the extra info. Definitely something I'll come back to.

My local electronics store had a "Black Friday" deal on one of these guys:

http://www.rpelectronics.com/fx888d-hak ... n-65w.html

So I treated myself. I've not tested it on brass sheet yet, but it worked excellently on tinplate. I built myself one of the tinplate girl 7/8ths tipper wagons.

[/img]

[ge_rik]

I've not tested it on brass sheet yet, but it worked excellently on tinplate. I built myself one of the tinplate girl 7/8ths tipper wagons.

[/img]

Blimey - that's good for a first go. Only hope my efforts turn out half as good.

Rik

[dizzysteamer]

That's a lovely job scratch building at its best you have me thinking now as I am considering a little train of hopper wagons for my little diesel loco.

A solder station is good, some are very cheap now too.

At the end of the day it is a temperature controlled iron which is exactly what you need for projects that take time to put together.

dizzysteamer

[LNR]

Hi Ted,
Top job on the little hopper. They look very interesting (unfortunately not my scale) plenty of scope for weathering, rusting and general knocking about.
Grant.

[big-ted]

Hi Ted,
 Top job on the little hopper. They look very interesting (unfortunately not my scale) plenty of scope for weathering, rusting and general knocking about.
Grant.

I'll admit, my intention had been to build one as the plans intended to figure out how best to scale to 16mm. However, there are a number of parts that I think would be very fiddly to do if dimensions were ~40% smaller, so this is not as simple as just scaling the plans, unfortunately.

[GTB]

Any tips on how to avoid distortion would be appreciated by me.

Brass is more of a problem to soft solder, as it conducts the heat away more rapidly than nickel silver and steel. I always tin both parts in the area that they will be joined, set the parts up, flux the joint and then sweat the joint together.

To avoid distortion, the best way is to tack the pieces together first, check everything is nice and straight and square, then finish off the joint, working back and forward in sections to stop the parts expanding too much and keeping the assembly from getting too hot.

Tinning is much easier with an iron, as the tip can be used to move the solder and flux pool around with a wiping motion, but a torch can do the sweating part. I mostly use a 100W soldering station for soldering brass sheet together and keep the torch for sweating together large chunks of brass like cylinders. When I got the soldering station, it came with a 1/16" bit, which is OK for electronics, but useless for sheet metal. I bought the largest bit available for that model and have no problems. I just change the bit back when using the iron for electronics.

Steel is easier to work with as the heat stays where you want it. Tinplate is even easier, as the steel is already tinned, so tin/lead solder wets it nicely and it is easy to sweat the joint together neatly.

The first commandment of soldering is to keep everything clean. The second is to use plenty of heat and get in and out quickly.

Using undersize soldering irons just results in more distortion, especially with brass, as it takes longer to make the joint and everything gets hot, instead of just the area where you are working. So more chance of melting another joint and watching it all fall apart as well........

Check out the range of Carr's solders and fluxes, as they do a range of solders for what is called step soldering. You make the main joints with a high melting point solder, then add detail parts with lower melting point solder, much reducing the risk of the whole thing falling apart as you add the last piece.

A great local modeller that we lost last year always swore by Baker's Fluid and his old Scope iron. Certainly one couldn't argue with the results he got.

My problem with Baker's is that it is basically killed spirits (hydrochloric acid neutralised with zinc) and I won't let anything in the workshop that contains chloride. If you use it, scrub each joint with Ajax cleaner and an old toothbrush as you go, or corrosion can set in, especially with steel.

Personally I use Phosphoric Acid for all my soldering, as I can use it for ordinary tin/lead solder and low melt solder and it works on both brass and steel. It even seems to work with the crappy lead free solder that the EC is foisting on everyone, although we can still get tin/lead solders here in Oz. The joints don't have to be cleaned up as quickly, but the assembly still needs a good scrub down at the end of the day.

Not having asbestos fingers, I have a large collection of small clamps and assorted sizes and shapes of squared up blocks of wood, that I use to hold parts together while I sweat the joints.

If you haven't built any etched brass kits in your small scale past, I'd suggest practicing for a while with bits and pieces of brass sheet until you get the feel for the work. Use some of the etch fret if necessary, although it's not a good idea to remove any parts from the fret until they are needed.

What kit are you planning to build? Sounds like the Worsley Works CDR/IOM Walker railcar........

Regards,

[ge_rik]

What kit are you planning to build? Sounds like the Worsley Works CDR/IOM Walker railcar........

Regards,

Hi Graeme
Thanks very much for the tips. Plenty to get my head round here. I've done odd bits of brass fabrication before, but nothing large scale with bigger pieces - so your guidance is very helpful.

The kit was made by John Campbell, of Walker railcar No.10 (former Clogher Valley). I've always fancied that one with its half-cab (but of course makes construction a wee bit harder). I was admiring a model of the railcar at the Llanfair Show and the chap who made it told me it was made from a kit produced a few years back by John. As John was also exhibiting at the show (a couple of really well made scratchbuilt diggers) I got chatting to him. Turned out he's a great fan of Deltang gear and had already bought some stuff from me - so he agreed to send me a kit and I agreed to construct a special transmitter for another model crane he's constructing. The kit isn't complete - there are no mouldings for the roof and for the rear of the railcar (which were originally supplied in resin), and there are no instructions - so it will be very much a voyage of discovery. Probably not the best way to start out on my first brass kit construction - but I'm always up for a challenge.

It's fairly obvious how the big bits will go together but there's a heck of a lot of little bits whose purpose, I hope, will become more apparent as I start construction.

Rik