fabrication techniques: soldering

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fabrication techniques: soldering

John Greenly
This post was updated on .
Jim asked if I would start a thread on soldering methods.  I'm no great expert, but I have had some good success, so I'll start it off.  I'm sure others will have better ways of doing things.  There are certainly some basics that are always important. Here are some that come to mind.

First, and this can't be stressed enough, good fit of parts makes the job easy and good.  Solder can fill big gaps but it's greatly preferable to have joints a good snug fit, and especially to have no stress on the assembly before soldering.  Don't use the solder to hold together parts that want to spring apart or go crooked, it's asking for trouble.  A nice close fit uses the solder's wetting properties to draw it completely into the joint with no excess necessary, and solder's surface tension will pull the parts together nicely.  Use fixtures, jigs, gravity, etc. to position the parts as you want them, but don't use clamping pressure to make up for poor fit.  

Design parts with soldering in mind, choosing thickness and mass to allow heating locally where joints are to be made, while limiting heating of large masses.  Thin sheet is easy to heat and doesn't conduct much heat away to other areas. This is well understood and crucial in good design for welding, but it's equally valuable to ease the soldering process.  Stainless steel solders beautifully and has very low heat conductivity so it can be helpful in tricky situations  where heat needs to be carefully localized.

Many metals can be soldered, from aluminum to stainless steel to titanium, if you have clean mating surfaces and use the right flux.   Flux is probably the most important contributor to good results.  If you apply heat and can't get solder to melt and flow promptly, it's probably flux that's needed.  By the same token, you can use flux to guide solder where you want it, and keep solder away from where you don't want it.  That means applying  flux accurately in the smallest possible quantity, so it doesn't creep across surfaces where you don't want solder to go.

Not only must flux do its job, it must be entirely removable afterward to allow paint or other finish to adhere, and to avoid continued etching or corroding over time.  Don't ever use plumber's paste flux, it will not come off unless you like to poison yourself with trichloroethylene.  Even sandblasting doesn't get it all off until you destroy your nice surfaces.  

Flux has two functions, first to clean surfaces, and second to exclude oxygen to prevent oxidation during heating.  Flux typically cleans  by etching with some type of acid, either organic acids as in rosin fluxes, or commonly hydrochloric acid usually combined with zinc chloride, in various water-soluble formulations.  Rosin is also not easy to get off, and nowadays I use only water-soluble flux.  There are many brands, I have been using Stay-Clean flux (goes with Stay-Brite solder), which is excellent and widely available.  I use it for all brass and steel soldering.  It is very thin and wicks into joints wonderfully well.  I clean parts afterward in warm water with a toothbrush.  

Solder comes in hundreds of formulations.  For brass and steel I use two types.  Standard 60-40 tin-lead solder (not rosin core, I use it with the Stay-Clean flux) has probably the best, easiest working properties on brass,  and Stay-Brite solder (96% tin, 4%silver) flows just about equally well when used with its flux.   Melt temperature is about 40C higher for the tin-silver,  which helps in multiply soldered assemblies. Do major joints with this first, and then add small parts with tin-lead.  

Possibly the most important thing about solder is to use the correct amount of it.  Avoiding having too much solder is the name of the game. There are many ways.  pre-"tinning" of parts by applying a thin coating of solder before joining is often very helpful, but it has the drawback of introducing extra thickness between the parts until it is melted, making precise locating difficult.  Solder comes in many forms, and for model work we can take advantage of jeweller's techniques of using tiny snippets of thin sheet solder, or small bits cut off the end of thin wire solder, to get just the right amount.  I use .020" diameter 60-40 solder for most work.  Rarely in model work is it wise to apply solder directly from the roll to the work-  you'll melt far too much!  I'll demonstrate some other ways of controlling this.  

Finally, heat.  I use a good temperature-controlled soldering iron, and a butane micro-torch.  The quality of the soldering tip is maybe the most important thing about a good soldering iron.  Good tips are typically iron-coated, or other proprietary formulations that keep the tip clean and wettable.  It is useless to even try to use an iron with a tip that doesn't instantly wet when solder is touched to it.  The tip must carry solder to the work, and then the effective application of heat depends on heat conduction through the solder itself.  With very, very small parts a dry iron can be used nicely, but otherwise you need that good heat transfer that a wetted tip provides.

I use a Pace iron (a standard temperature-controlled electronic soldering unit), their tips are very good. I use a variety of shapes, and a company called Plato sells them cheaper than Pace ( I think they actually make the Pace tips, they're identical).   Weller tips are also excellent.  Any of the acid fluxes will eventually degrade the wet-ability of the tip, but lead solder will rehabilitate it.  I always clean the tip well after using, and then coat it with lead solder.  If a tip does get bad, I have found that Oatey No.95 tinning flux does a nice job of cleaning and reconditioning it.  This is a paste flux, use it on the tip only- not on the work!  I just use a paper towel to wipe and clean the tip, and also a wet sponge.  

The butane torch is great for applying a lot of heat quickly, for instance to attach a part to a large assembly without heating the whole thing up. I used to use a big old iron with a huge tip for lots of heat, but the flame is better.  It is however easy to overheat and oxidize brass.  I've never used resistance soldering, I'd be very interested to hear of experience with this technique!

Okay, that's way more than enough talk.  In a following post I'll illustrate with a small soldering job.

Cheers,
John





   
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Re: fabrication techniques: soldering

Jim Courtney
Exactly what I've been looking for, John!

So, plumbers paste acid flux isn't a good idea? The Fast Tracks guy recommends using paste flux for soldering nickle silver rail to the copper PC board ties, using his aluminum building jigs. I've always scrubbed the final switches in hot soapy water after assembly. Will my switches eventually fall apart from the chronic activity of residual flux?

Locating parts accurately when finally soldering them together has always been a challenge for me, like an air pump casting to the rounded edge of a boiler.  Lately, I've taken to drilling and installing small pins of 0.020 or 0.025 wire in the parts, so's they don't drift out of alignment when heating the parts (PBL resistance soldering set).

I've only used a butane torch for disassembling brass models for prior to rebuilding -- but I've always been far better at taking brass locomotives apart, than putting them back together!

I'm looking forward to seeing your methods illustrated . . .





Jim Courtney
Poulsbo, WA
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Re: fabrication techniques: soldering

snapped_bolt
In reply to this post by John Greenly


   Wow....

      This could wind up being a very useful thread!
      I was wondering if paste solder could be useful for models. Years ago I managed to repair a radiator leak with a paste solder. I must have followed the instructions perfectly that day, the leak was stopped for good.
      Definitely curious about the paste solder possibility.

        Cheers!

         Stan
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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
In reply to this post by John Greenly
Last evening I made up a water hatch for my C&S intermediate tender.  Here are some photos to illustrate soldering methods.

I'm making something like this hatch on 68's tender (p. 166, NG Pict Vol. VI):



Start with a strip cut from .005" brass (for HO scale), emboss rivets for the joint in the can:



Bent into shape around a drill bit shank, the riveted edge tapered, and overlapping the other inturned edge to make a thin overlap.  This shows the amount of Stay-Clean flux applied- a barely visible droplet on the needle tip.  It wicks down into the joint when touched.



Touch the solder on the tip to the top end of the joint, and in about 2 seconds it heats the work and the solder flows down the length of the joint. (it's already soldered in the picture, I forgot to take a photo beforehand).  This shows the amount of solder that I put on the iron tip for this joint.   It all flows in.  The reflection makes this look like a big blob of solder, but it's really very thin on the iron.



Here's the soldered joint.  I would usually make a smooth cylinder by butting the edges together and soldering and then the joint disappears, but I decided to use an overlap to show this riveted joint.



Here's flux applied inside the can for the can-to-bottom joint:



and here's the solder pre-applied inside the can:



I applied a tiny amount of flux on the edge of the can, then set the bottom on it and soldered by applying heat to the bottom with a wetted tip.  I left the blob on there to show you a trick.



Solder (this is Stay-Brite, lead solder is even softer and easier) is very nicely carve-able with an Xacto blade.  I shaved off the blob.  This solder carving is extremely useful for cleaning up all sorts of situations.



here's the soldered result.  The solder forms a fillet at the joint, the more solder you apply, the bigger that fillet will be.



And here it is on the outside, after filing the bottom edge to size:



I put the top on the same way, also with Stay-Brite.  heat applied to the top quickly makes that joint without re-melting the bottom.

Here are the hinges formed and ready to go on, with soft (lead) solder.  I cut them apart after forming and tinning the inside with solder, then hung them on the hatch, maneuvered and then held lightly in place  with the point of a jeweler's file (a very nice locating tool, holds the part without marring if you are gentle) and heated each one with a barely wetted tip.  I carved off the tiny amount of solder left behind on the outside of the hinge.



Finally, here's the handle going on.  I fluxed and tinned the handle ends, then put a tiny bit more flux on and held the handle in place while I heated the nearby edge of the top with an almost dry iron.



Here's it is done except for a bit of smoothing and polishing:



and here it is in place on the tender:





 Well, time to put some water in that hatch and send the engine home, running light,  in time for Christmas.  Best wishes to all the crews of your engines too,

John





















 











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Re: fabrication techniques: soldering

Pat Student
In reply to this post by John Greenly
One of my favorites is TIX Solder along with TIX Flux especially for the application of the "final" details, a low melting, high strength solder.  They also make an anti-flux, though I have no experience with it.

I use TIX flux mostly.  The purpose of flux is to protect the surfaces being soldered from oxidation.  I've even used rosin flux to add details.

The secrets to successful soldering are:
   • clean surfaces to be soldered
   • clean solder ( no corrosion build up)
   • sufficient amount of flux
   • sufficient heat to solder the joint in question without affecting other joints in the area
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Re: fabrication techniques: soldering

South Park
  This is great intel !

  Taking this to full scale, I have been reluctantly been mulling the
idea about in my head for several years of adding brake lights and
turn signals to my truck:



  Now, to be clear, I HATE modern crap showing up on old cars !
Capturing that period look and feel is more important to me than
anything with my vehicles, and it is hard to express my disappointment
when I see cheesy plastic, off-the-shelf lights, colored plastic-coated
wiring, and modern switch hardware and connectors bolted on to
an early car.  To make matters worse, it is ALWAYS accompanied
by the brain dead response about "safety", never addressing the part
about "I'm too lazy to really make an effort" to do it in a way that
matches the vehicle.

  So,   ...  to not be "that guy", I swept away the dust in my memory
files and pulled up some images of cool old brake lights and turn signals
and began searching to find some.  These were just the ticket, and I then
began the welding, soldering, fixing, painting process, not too dis-
-similar to what we are reading about here.



  I guess I don't have a photo of the "STOP" light I will be using, but I
located a period red glass lens that has raised letters and blacked-out
relief panels, alerting those following that my vehicle has had the brakes
applied, and mated it to a 1920's housing that looks right.

  Now, the most relevant part of this topic to the discussion of brass
locomotive soldering is the appearance-grade work of the steering
column mounted switch.
  I started with an original clamp-on horn button housing and after
MUCH failed fabrication theorizing and attempts, discovered to my
delight that 1" hard copper plumbing/fittings were a near perfect fit
to both the stock horn button housing AND available 3-position switches.
Soldering these up was a cinch, but did require a super clean finish.
  With this done, I now had a place to mount my switch.  But modern
switches simply do not look anything like what was being used in 1920,
so something would have to be made.  Complicating this, is the fact that
I would need to make whatever I made WORK with a good electric
switch AND not render it non-functional in the process because of the
heat of soldering ...  plastic internal parts.

  This is what I ended up with:



  The paddle-shaped end knob matches the stock spark and throttle levers
already on the column.  I made the handle with a 16p framing nail.  Got the
head red hot and beat it into a flattened disc.  I then buried it in brazing brass
to get a closer form, then covered that in solder to file and fuss into a more
finished shape.  I then turned down this work and the stock switch knob to
.14" and cut a brass tube sleeve that tightly fit over both and soldered the
essembly into one piece.

  Next up is a lighted dash indicator.  These vehicles are not quiet inside, so
to avoid going down the road for miles with a blinker on, I have devised a
plan to put discreet lights on the dash to show left or right, using tiny 3mm
diode lights, set in black housings.  They are smaller than a pencil eraser
and should be missed by all but the most foaming of purists.

  All this, so the wifeperson can find something else to plex about when I
go out driving my old contraption in a world of wannabe stunt drivers.

"Duty above all else except Honor"
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Re: fabrication techniques: soldering

Jim Courtney
In reply to this post by John Greenly
Great info, John!

Some questions --

When I search for Stay-Bright, I find their solder, but the flux is labeled "Stay-Clean" -- is this the stuff you use?

How would you go about laminating two layers of metal (brass or nickel silver) together, as in building up layers of cab sides or frame sides. Would you tin the inside surfaces of both, or clamp them together, apply flux to the edges and let solder from the iron flow into the joint??

I ask because of this:




Bill Merredith (The Leadville Shops) swears that there is a Cooke 2-8-0 hiding in there  -- all I have to do is carefully remove the nickle silver etchings from their frets, clean up with a file, fold as indicated along etched fold lines, then solder everything together. Note the cab has a one piece folded under layer, and the outer panels are soldered on to build up the relief. Same process for the frame.

Any particular solder that you would recommend for nickle silver etchings??

Merry Christmas,

Jim
Jim Courtney
Poulsbo, WA
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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
Pat, yes, thanks!

I used to use Tix a long time ago, forgot about it.  It is excellent, melts far below 60-40 so you can easily add small parts to a larger assembly.  Only caveat is that if you ever have to heat up to remove or change something else that's joined with other solders, all the Tix parts will fall off (don't ask how I know this).  I have been doing fine with the differential between 60-40 and Stay-Bright, but I'll get some Tix now that you've reminded me!   The  Tix flux is very nice too, water soluble and behaves very much like the Stay-Bright (Stay- Clean, yes!  Jim, sorry I forgot what it's called, I'll edit my posts).   I did use the Tix anti-flux, it coats surfaces to keep solder from flowing where you don't want it to go.  I generally didn't find it necessary, with careful planning of how and where to introduce the flux and solder in suitably limited amounts.  

Jim,

nickel-silver solders pretty much exactly like brass, very nice to work with, use the same solders, fluxes and methods.  Your two-layer cab assembly is just what I was going to be making for the next step on my F&CC engine- making the interior window sashes.  If I get to that soon I can take some pics and post the process if you like.  Generally I would not tin the joining surfaces, but rather just position and hold the two layers accurately so they lie very flat against each other, with some flux in between, and then feed solder in from an edge very sparingly.  That means that it is extremely important to keep the parts flat while working with them.  It's almost impossible to perfectly flatten out a piece of sheet metal that's been bent or dented even slightly. If things are well prepared and located the solder will flow in beautifully and form negligible filleting where one piece overlaps the other, such as at a window frame.   And remember, you can always scrape off a small amount of excess very neatly- grind an Xacto blade to exactly the shape to do the job.  
 

For a two-layer window assembly you could even consider not bonding the entire joining area, but soldering only at corners or outside edges  so  there's no solder at the window sash but it just sits tightly against the other layer.  This will look more like a separate window, and that's what I probably will do.
Those etched parts look beautiful, what a great project that will be!  You should document it for us.

Cheers,
John



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Re: fabrication techniques: soldering

Pat Student
John

Some excellent comments.

I'd like to add some to Jim's project.  The two layers must be well clamped, hemostats are a an excellent choice.  I'd use solder of a diameter that is approximately the thickness of the the two pieces.  Once the solder flows, stops applying, as there is adequate solder for the joint.  Heat on the outside edge or use a resistance tweezer so both pieces are heated equally.

Pat
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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
In reply to this post by Jim Courtney
Jim Courtney wrote:

So, plumbers paste acid flux isn't a good idea? The Fast Tracks guy recommends using paste flux for soldering nickle silver rail to the copper PC board ties, using his aluminum building jigs. I've always scrubbed the final switches in hot soapy water after assembly. Will my switches eventually fall apart from the chronic activity of residual flux?

Locating parts accurately when finally soldering them together has always been a challenge for me, like an air pump casting to the rounded edge of a boiler.  Lately, I've taken to drilling and installing small pins of 0.020 or 0.025 wire in the parts, so's they don't drift out of alignment when heating the parts (PBL resistance soldering set).

Jim,
I doubt that the residual paste flux will cause any real trouble in that use.  The paste is not highly active at room temperature, but over a very long time it might degrade the surfaces it's stuck to, and it's gummy and other stuff sticks to it.

Using locating pins or other features on parts to hold them aligned for soldering can be a great help, and can result in a stronger joint as well.  If you think about this in the design phase it can be fairly easy and convenient to do.  


Pat,

thanks for more good input!  I forgot to say that one of the good things about ordinary 60-40 solder is that it comes in small diameters, so important for metering small amounts.  I use .020" diameter solder for almost all work.  

thanks,
John
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Re: fabrication techniques: soldering

Jim Courtney
In reply to this post by Pat Student
Interesting, Pat,

Bill Merrideth warned me off from using resistance soldering tweezers on the etched N.S. parts, says it is overkill.

He recommended a temperature controlled iron at 700 degrees. He says nickle silver conducts heat so poorly that you can actually hold pieces with your fingers while heating the surfaces / edges locally. He only uses the tweezers for attaching large brass castings, heating the pre-tinned casting with the tweezers, heating it up so as to sweat the casting onto the N.S etching surface.

I was planning to use small brass alligator clips with smooth jaws, to hold the parts together -- think this will work?

Also Pat and John, is there any use for solder paste (small particles of solder suspended in liquid flux, various silver contents, usually sold in syringes) in brass locomotive construction?

I'm learning a lot here!
Jim Courtney
Poulsbo, WA
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Re: fabrication techniques: soldering

Charles McMillan
In reply to this post by John Greenly
A trick I had learned about controlling where solder went , was to use a Number 2 pencil and draw line to contain where the solder flowed. You sort of corralled the solder and it wouldn't flow across the pencil line.

I use .020 diameter solder for most of my work. I flatten it and the cut it into smaller pieces and place on the joint to be soldered. A well fluxed joint and the solder will flow right into it when heated. I use a jeweler's torch for my model work and only use an iron for the very smallest of parts. Brass wire is an area where an iron works better for building piping on under frames for cars.  Practice and more practice using whatever tool you find the best.

My example posted is in Fn3 from years ago. If it was in HOn3 it would be less than 2 inches long. That would be a project  to try.




Charles M
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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
In reply to this post by Jim Courtney
Jim,

That's interesting about the resistance soldering.  I'd like to learn more about it.   I guess it's a very good way to apply very intense heating to a very small local area on a larger assembly.  

As to temperature, solder melt temps are:

Stay-Brite -- 221C  (440F)

60-40 tin-lead  --188C (370F)

Tix  -- 135C (275F)

So you don't need anywhere near 700 degrees at the joint.   But, you generally want to heat the joint locally in a reasonably short time (soldering in an oven can work wonderfully if you want to heat an entire assembly).  The rate of local heating depends on the temperature of the heat source, the thermal conductivity from the source to the joint, and the rate of heat loss from the joint location to the rest of the parts or other objects in contact, like clamps or fixtures.  Thus the iron tip needs to be hotter than the melt temperature to heat the joint area in the required time.  The faster you need to heat and the larger the mass that will be heated, the hotter the iron needs to be.  I adjust the temp of my iron according to these variables.  

As to clamping,  with small parts or thin sheets, for the reasons stated above it's generally very helpful to thermally insulate the clamps or other fixtures from the parts to be heated.  You can do this with cardstock, though it won't last long. I do it nowadays with polyimide tape (Kapton is one brand name).  Polyimide is amazing stuff, with a safe working temperature of 400C.  It's a superb electrical insulator and good thermal insulator, it is very tough mechanically, has high abrasion resistance, leaves no residue on the work, and is not affected by flux.  It comes in various thicknesses, I usually use 2 mil (.002").  You can buy it from industrial suppliers like McMaster Carr.  I often use machinist's parallel clamps, sprung tweezers or hemostats to hold work, and I cover the jaw faces with pieces of polyimide tape.  You could do the same with your alligator clips.

I have not used paste solder in modeling. The only type I know is paste flux with powdered solder mixed in.  Thus all the bad features of paste flux are built in.  If you are looking for solder in some other form for a special job, look in jewellers' supplies.  As I mentioned before, they use very thin sheets or strips of solder that can be placed in between parts, or tiny pieces cut off and placed suitably to enter a joint when melted.  I have not found a need for these.  As you can see from my small project above, there are lots of ways of getting just the needed amount of solder where you need it.  I can cut off very small bits of the .020 diameter solder that I use, or just melt off a tiny bit onto the tip, and then apply it to the work.

cheers,
John
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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
In reply to this post by Charles McMillan
Charles,

wow, that's absolutely beautiful!  Wonderful work.  Love those louvers, and the radiator shell is a masterpiece.  I sometimes think (well, always, really) that I'm crazy to be working in HOn3.  It's possible to do really breathtaking stuff in the larger scales, as you demonstrate!

In my small scale (the tender I used as illustration is 2 1/2 inches long)  I use the torch on relatively large parts, though often just to locally heat a larger assembly really fast to join a small part to it.  The water hatch I illustrated needed about 2 seconds to reach melt with a small, fairly cool iron, and with a torch it would be red-hot and ruined in the same time unless you keep your distance very carefully.

But you're absolutely right, the particular tool you use is not as important as your practice and facility with it.

Your pencil line trick for blocking solder flow is a new one on me, I'll try it!  (believe it or not, there are special solders made for bonding carbon fiber components. But our ordinary solders definitely do not wet graphite-- that must be how the pencil works)

many thanks,
John
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Re: fabrication techniques: soldering

Robert Stears
In reply to this post by Jim Courtney
Fantastic! Thank you very much.
Bob

Sent from my iPhone

On Dec 24, 2018, at 12:52 PM, Jim Courtney [via C&Sng Discussion Forum] <[hidden email]> wrote:

Exactly what I've been looking for, John!

So, plumbers paste acid flux isn't a good idea? The Fast Tracks guy recommends using paste flux for soldering nickle silver rail to the copper PC board ties, using his aluminum building jigs. I've always scrubbed the final switches in hot soapy water after assembly. Will my switches eventually fall apart from the chronic activity of residual flux?

Locating parts accurately when finally soldering them together has always been a challenge for me, like an air pump casting to the rounded edge of a boiler.  Lately, I've taken to drilling and installing small pins of 0.020 or 0.025 wire in the parts, so's they don't drift out of alignment when heating the parts (PBL resistance soldering set).

I've only used a butane torch for disassembling brass models for prior to rebuilding -- but I've always been far better at taking brass locomotives apart, than putting them back together!

I'm looking forward to seeing your methods illustrated . . .





Jim Courtney
Poulsbo, WA



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Re: fabrication techniques: soldering

John Greenly
This post was updated on .
In reply to this post by Jim Courtney
Jim,

nickel silver alloy does have relatively low heat conductivity, almost as low as stainless steel.   By comparison, brass conducts heat about 3 times faster, and pure copper about 12 times faster. By the way, you may know that nickel silver (also called German silver) is basically brass with tin added- typically 60% Cu and around 20% each of zinc and tin.   It does not contain silver, it's the tin that  gives it its color.  This alloy has relatively low electrical  conductivity, so a long run of small rail can cause voltage drop to your locomotives.  But it has the important advantage that the oxide that forms on its surface is electrically conductive- it doesn't corrode or tarnish like copper, silver or brass, and that's why we like it so much for rail: good electrical contact.   Also by the way, the usual brass (standard 360 free-machining alloy) that most of our models are made of contains around 2% lead, which gives it those nice easy-working properties.  Some investment castings of detail parts are made from lead-free alloys and are much harder and more brittle- be careful!  Note: this means that filings from brass work can be sources of lead if ingested and exposed to stomach acid.  Don't let the cat step in the dust you made and then clean her paws!

John
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Re: fabrication techniques: soldering

Jim Courtney
This post was updated on .
Maybe that's why all 3 of my cats died . . .

And probably why I keep breaking drill bits when I try to drill into brass castings!!
Jim Courtney
Poulsbo, WA
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Re: fabrication techniques: soldering

Jim Courtney
OK, another question for John and Pat:

Is Tix solder, with a melting point of "135C (275F)", safe for soldering brass to white metal (like the Railmaster locomotive kits in Sn3)?

If not, is there a safe solder for white metal? What about fluxes for this metal?

Jim Courtney
Poulsbo, WA
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Re: fabrication techniques: soldering

Paul R.
Jim Look up Carrs  solders,on line . They have solders from 70c to245cand fluxes you may be able to get them in the US I have used their 70c solder on white metal, the 145c is a good one for detailing. Paul R.
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Re: fabrication techniques: soldering

Jim Courtney
This post was updated on .
Thanks, Paul.

Silly me, I always thought that solder is solder, varying only as rosin core for electrical stuff vs solid for everything else.

Instead, solders are like drill bits, you need a wide variety of sizes (melting points) for various needs. I can see now how to theoretically build up assemblies and add them to a brass locomotive, working from high melting point solder for the heavy stuff down to low melting point for details like piping.

Maybe everything doesn't have to fall apart when you apply heat to it.
Jim Courtney
Poulsbo, WA
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