I need advice on soldering a brass car

[chicken45]

I'm talking about the TrainCat GRa.
The side sills. How do I solder them? I am folding a car side back on itself. What's the best way to solder this?

I've got about 2 lifetimes worth of that Supersafe #30 gel, liquid, and ruby, and a variable temp iron with a small chisel tip.
I have solid wire 96% tin 4% silver 1/32, and some 62/36/2 rosin core .022 diameter solder.


And after I get the sides together, how do I solder the outer rivet plates cleanly and without heating up the brass enough to undo everything?

[Chris333]

put the flux in the middle and fold the parts over. Load up the tip with a small amount of solder and touch it to the edge and it will wick down into the parts.

I haven't even unpacked mine yet, but the overlays are sort of the same. I would hold them in place with sprung tweezers and touch the edge with the iron.

[robert3985]

I'm talking about the TrainCat GRa.
The side sills. How do I solder them? I am folding a car side back on itself. What's the best way to solder this?

I've got about 2 lifetimes worth of that Supersafe #30 gel, liquid, and ruby, and a variable temp iron with a small chisel tip.
I have solid wire 96% tin 4% silver 1/32, and some 62/36/2 rosin core .022 diameter solder.


And after I get the sides together, how do I solder the outer rivet plates cleanly and without heating up the brass enough to undo everything?

When building brass models with layers and parts that need to be soldered to already soldered surfaces, the best way to do it is to use your Supersafe flux and solder that has a higher than usual melting point for the first solder.

Solder progressively, using progressively lower temperature solders for additional layers.

For instance, use your 96/4 Tin/Silver solder (which melts at 460 deg. F) to solder the first layer together.  Then, solder the next layer using 91/9 Tin/Zinc solder (which melts at 390 deg. F).  Your Supersafe #30 will work just fine with both solders to solder brass and nickel silver.  Your rosin core solder probably has a melt temperature that's different than the 96/4 Tin/Silver solder and you might be able to use those two if their melt temperatures are different enough.

You should be soldering on a soldering pad that's hard, which you can get at your local jewlery store or supply, such as this one: http://silentgoddess.indiemade.com/product/hard-solderite-soldering-pad  so that your support surface doesn't bow when you press down on your sides when soldering.

The technique would be to tin one of the layers thinly with your highest temp solder first, using your flux and a clean, wetted wedge tip.  Let it cool, then position the part (folded I assume) and flux again.  Apply heat with your iron (or a heat gun with a localizing attachment) and press down on the part you're soldering with something metal like the points of a pair of stainless tweezers, or for larger areas, a stainless fork (the kind you eat with), using the tines to hold the pieces together until the solder cools, then moving on further.

After the first two pieces are soldered together with your highest melting temp. solder, do the same thing with the next layer, or pieces forming that solder layer, using your lower melting point solder to tin the pieces.  Watch the solder and as soon as it gets shiny and you feel the part "settle" (tin it first, just like the first "layer"), take the heat off, let the solder cool and progress further.  The first solder joint should not melt.

If you've got a third layer, use another even lower temp solder and do the same things.

Having built a few of Bob's Train Cat kits (signal towers) I use my American Beauty 250 Watt Resistance Soldering Station, which allows me to hold/heat/hold/cool all at once using the same tool, so even if the first solder joint melts when applying the second, it's all being held together by either the electrode or the tweezer, so it stays together.

You asked what's "best"....and a resistance soldering station makes building brass models a LOT easier, but it's a $500 plus investment, and I would not even consider cheaper versions than the American Beauty Resistance Soldering Station although a lower wattage unit costs less than the top-of-the-line 250W kit with electrode and tweezer.

Frankly, if you're going to be building brass kits or models regularly, I'd save my nickels and dimes to get one ASAP.

Here's a photo of one of a Train Cat UP cantilever signal bridge with scratch built brass D-type signal heads and a lot of added brass and wood details which I installed on my buddy Nate's layout at his Riverside scene:


Here's one of my totally scratchbuilt UP cantilever signal bridges built using different melting temperature solders, and an iron and torch.  It took me a LOT longer to put this together than the TC kit just because the resistance solderer makes it so much quicker.  However, it still got built, even without the expensive equipment:









 

[sd45elect2000]

I agree that the American beauty is a fine machine. I've used it on a few of Bob's bridges, Fast work. But it is expensive.

Randy

[DKS]

Frankly, if you're going to be building brass kits or models regularly, I'd save my nickels and dimes to get one ASAP.

Having built quite a few of these and other kits as well, and also owning an American Beauty, I can say that the advantages of the $500 resistance iron over a decent thermostatted $90 iron are, IMO, marginal. It's down to personal technique and personal preferences, and you can accomplish the same level of soldering quality with an ordinary iron. Again, this is my opinion, but don't be pressured into making a huge investment just yet.

[mark.hinds]

Having done a lot of fancy soldering on brass locomotive shells, I agree that the resistance soldering machine is a big advantage.  That being said, however, you can get by with a regular iron if you have adequate heat transfer from the iron, and are willing to creatively use techniques to protect existing joints, like heat-sink tweezers and damp pieces of toilet paper.  I accidentally unsoldered the end bulkhead on one of my Samhongsa F7s prior to learning this (...).

I didn't use different types of solder on the same model as suggested by Bob above, although that sounds like a useful technique if all else fails. 

MH

[Chris333]

I ended up soldering the sides and ACCing the rest:

[robert3985]

You'll note the OP asked for "...the best..."  There are obviously other methods that might/will work, but "...the best..." for the sheet-metal car kits is the American Beauty.

Also, no pressure to get one, but you'll note that several of us have decided it was something we needed.  I use both a Smith Little Torch Oxyacetylene Kit (was around 600 bucks) and several different sized and wattage irons for various projects because they work quicker and better than the American Beauty for some applications, and I've used a heat gun lately for Proto87 Stores' etched frog kits, which are three-layer assemblies.

So, there are all sorts of methods to get solder to melt and to hold the parts together and heat-sink parts so they don't come unattached during assembly and the wet rag/wet toilet paper trick, or the hemostat heat sink trick, or the laying a piece of thick brass sheet on part of your kit to draw heat away trick...all work okay but only experience will tell you what to use and every brass model needs different tricks to get it all soldered together.

[DKS]

You'll note the OP asked for "...the best..."

Well, not to pick nits, but I think you're taking a remark out of context. The OP stated,

The side sills. How do I solder them? I am folding a car side back on itself. What's the best way to solder this?

Resistance soldering is not really going to offer any advantage over conventional iron soldering in this case, since it is one folded piece of brass. Indeed, sometimes the iron will have an advantage in situations such as this by being able to transfer more heat over a larger area. Chris' response IMO was the best in this case.

Now, as to the rest--

And after I get the sides together, how do I solder the outer rivet plates cleanly and without heating up the brass enough to undo everything?

There you have a point about resistance soldering. That said, I think Chris demonstrates that one need not solder absolutely everything for a clean build.

[Chris333]

The sides are folded twice. The sill is half etched so there is another full etched sill at the bottom that folds under the first. Then there is the post rivet overlays that fold down from the top. I folded the bottom and soldered the lower edge.

I fluxed and tinned the backs of the rivets. Then I fluxed where they fold to and bent them down. They are thin so I held them in place with the tip of a knife blade. The whole thing was sitting down on a flat piece of wood and I hit it with the iron till the solder on the back started to flow. Now if this heated up the first solder that was OK cause I was holding the whole thing down to a flat surface. A little torch might have been nice for this.

With flux and a hot iron it works so fast I don't worry about it un-soldering other stuff.

Anyway I think Bob glues the whole thing together.

[chicken45]

Thanks for the advice, guys!
I do not have one of those asbestos pads. I think I need to pick one up. I really need one and didn't know they were a thing.

DKS- you are a super human. Maybe even more machine now, than man.
Charlie Parker gave what is considered the "best jazz performance ever" on a plastic saxophone.  It's not always the equipment, it's the artist...but for us mortals, good equipment helps.

Chris! Looks great! How did you secure the keel to the floor? Just by gluing the ribs?

My gondola book is in storage...can you tell me what trucks are correct for the GRa? Do you have any shots of your brake rigging?

[Chris333]

Brakes!  I just opened the package in post number 2.    here is what I have so far:


I did everything else with glue. I centered the 2 floor pieces and tacked them in place. Started adding ribs after that.

[Chris333]

Oh trucks. I think those Bowser trucks are correct. I got those Atlas 70T jobbers on there now.

[robert3985]

Well, not to pick nits...

     Hahahah..."nits" to you DKS are great, lumbering beasts, which you are compelled to "pick" 

Resistance soldering is not really going to offer any advantage over conventional iron soldering in this case, since it is one folded piece of brass. Indeed, sometimes the iron will have an advantage in situations such as this by being able to transfer more heat over a larger area.

Perhaps not in this specific case, which is why the vast majority of my post dealt with using an iron and different melting temp solders.  However,  merely transferring heat over a large area in a soldering context is only half the procedure.  The other half is finding a way to hold the parts together precisely, and when soldering folded parts, pressing them together is part of that procedure, which the pliers attachment on a resistance solderer can do much more effectively than an iron and an Xacto knife, or a Little Torch and a pick.  As I stated, even a heat gun is more effective than an iron in certain cases, such as soldering the three-layer NS frogs together that Proto87 Stores offers.

...I think Chris demonstrates that one need not solder absolutely everything for a clean build.

I agree 100%, but the question was how to "solder"...and then morphed into specific details about assembling this particular model (a good thing). 

For me, a "clean build" is only part of the equation.  The other part for me is a "robust build" because I take my stuff to shows a few times a year.

Along with Chris I believe that in a lot of cases Bob assembles his etched kits using various non-solder glues.  Since my layout is portable and I like to take what I build to the shows and that involves rougher handling than if everything just remained at home, I prefer to solder brass and NS because solder is more robust than CA and can better take the stresses of transport which I do with my stuff two or three times a year.

In my first post in this thread, I didn't 'splain fully why a "hard soldering pad" is essential.  In the TC kits that I've modified and assembled, the brass is very soft and bends easily...much easier than the "hard" brass I use when scratchbuilding...which is why when assembling cars or structures and soldering them together, a heat-resistant, hard pad is an accessory that's great to have so your car sides and structure components will be straight and not bowed or wavy 'cause you gotta press the parts together while heating them, and doing that on a pliable surface isn't a good procedure.  Maybe the brass is thick enough in the TC car kits to not warrant a "hard soldering pad", but since I haven't built a TC car kit yet, I don't know.  The TC kits I HAVE built really needed that hard surface for the model to remain true. 

[DKS]

The other half is finding a way to hold the parts together precisely, and when soldering folded parts, pressing them together is part of that procedure...

Folded parts do not need to be held together "precisely"... right? They just fold. I hold them closed with self-sprung tweezers. And when a relatively large soldering area is involved, I may not even worry about the small bits between the tweezers. Or if I do, I just move 'em around.

In my first post in this thread, I didn't 'splain fully why a "hard soldering pad" is essential.

I used a "hard" soldering pad for a while. After a bit, I found that it still wasn't robust enough for the job, and it had other issues. I then switched to scraps of plain PC board, one of the many advantages of which is that I can reliably tape parts to it in their proper orientation with masking tape, and the tape usually lasts just long enough for the typical soldering job. I then found that I can make a variety of very useful jigs out of PC board scraps that hold parts in all manner of orientations, which is quite impractical with soldering pads. I'm sure I could have found other ways to accomplish the same tasks, but I must say that a PC board work surface is superior to a soldering pad. Of course, YMMV.