I picked up a nice old Kemtron/PSC sheet brass caboose kit. I know soldering is the best way to put it together, but how to solder it is the question? I do have a nice high temp Weller electronics soldering iron or a small butane pencil torch. Wish I had a resistance solding unit, but those are big $$! Am I better off to just build it with Walthers goo or ACC super glue? Or is there a technique to solder something like this easily? Thanks for the help in advance. Mike
You build a resistance soldering unit from an inexpensive soldering gun like this one:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=4328
a foot switch (normally off), and the tweezers.
The hardest part is the tweezers.
Here are other methods:
http://www.girr.org/girr/tips/tips1/solderer.pdf
There is an article in Mainline Modeler, October 1995
http://erojr.home.cern.ch/erojr/Content/workshop/workshop.htm
http://web.inter.nl.net/users/FS160/fiNeweb/tools-RSU/RSU.htm
Krazy glue. A few years ago I talked to a guy who manufactured them and he says that using Krazy glue (cyanoacrylate) is heck of a lot easier than soldering. But be sure to paint the caboose and put in the window glass before you assemble it.
Easier perhaps, but not better. There is nothing as nice than a good soldered brass-kit. One advantage is that if you solder it, you can owen-bake the paint. Good luck.
I use an iron or a gun to solder everything. You will find the Weller electronics soldering iron pretty small for that kind of job. I’d want something closer to 100 watts. You ought to be able to find a plain old electric soldering iron for like $10. For an old kit, you want to be extra vigilant about cleaning the tarnish off every joint. After cleaning, use rosin flux and 60-40 tin lead solder. Avoid the “lead free” solders and the 50-50 solders.
As you heat the model to make the second (or third or whatever) solder joint you will find by the time that joint is hot enough, the previously made joints melt and fall apart. Jigs and heat sinks are your friend.
What do the instructions suggest? Always best to follow the manufacturer’s suggestions.
I’m not familiar with that kit, but any good-sized (80 watts or bigger) soldering iron should work, or you could use a propane torch, similar to those used by plumbers. Clean the areas to be joined using a fine grade of steel wool, then tin all mating surfaces. You may need to construct some simple jigs to hold everything in alignment for assembly - scrap lumber may work, as it’s only needed for one-time use.
After you’ve determined the best sequence for assembly - often making several sub-assemblies works well - begin by joining the largest pieces. Each time you need to add a new piece to a sub-assembly, pack wet paper towels around all previously-soldered joints - this will keep them from coming apart when you apply heat for the newest addition. After the major parts have been assembled, you can switch to a smaller iron for adding details - again, when working near other soldered joints, placing wads of wet paper towel or tissue will keep things from reverting to their original kit form. [;)]
I used a plumbers torch to solder this Kemtron cast brass cab together, first tinning all joints, then assembling the parts and using small clamps to hold everything in position. The torch was then used to heat the entire cab, fusing the parts together:
I then used a 200 watt iron to solder it to the boiler assembly (an old Akane 2-10-2):
The same iron was used to affix most of the major detail parts, again using wet tissues as heat sinks, then a smaller 80 watt iron for finer details and finishing up with a 25 watt for the piping:
Wayne
Looks good, and I will try that. Next part is how to cut the pieces from the piece of sheet brass. They are all on a single piece of sheet brass. Wish I had a small band saw. Plus there are windows to cut out. Maybe I will find someone to build the kit for me correctly. I can handle painting, just need it built. Mike
Is the sheet etched along the cut lines? If so, you could score along the lines with a utility knife, then flex the sheet back and forth a couple of times. The pieces should then separate from the sheet, although they’ll probably need to be cleaned-up with a file… Any chance you could post a picture?
Wayne
Wrong.
Athabasca scale model recommends CA cement, but soldering the model is FAR superior.
David B
I will get a pic later on. Its an older version of the kit, comes in a yellow Kemtron box that is about the same size as an Athearn blue box kit for a 40’ box car. Instruction sheet says you can build it with ACC or Solder it. not much help on how to cut out the parts from the sheet of brass, no it doesnt appear to be scored on the brass sheet. Not much to the kit, the frame is a brass casting, 4 walls, roof, roof walk way, then another 4 walls and a roof for the cupola. Maybe someone will offer to build this for me for a nominal fee.
I have an old brass caboose kit myself that I was looking at the other day. Mine was chemically formed into two sheets containing the various parts, a bag of zinc parts and wood. The brass is thin and can be cut with a razorknife and straightedge using a couple passes. Just don’t plan on using that razor for other work afterwards. I have also been playing around with soldering small parts together in proximity to other small parts which poses a challenge. I am using some Oately water soluable flux and 60/40 lead bearing electronics solder. The flux is nice because of its very smooth creamy consistency and being able to put a very small amount on with a toothpick. Only put flux where you intend to tin and use a small amount. with the solder pencil hot, put a small bead of solder on it and then touch it to the spot of flux. The flux will hiss and melt and then the little spot of solder on the pencil will just flow onto the spot. If the spot is the edge of a long piece, slowly drag the pencil down the area like you are using a marker. All you are trying to do is make it silver, don’t make any buildups. If you do, you started with too much solder or the part wasn’t quite hot enough. Do this to both parts. Put the parts together and try getting something to hold them that way. Fingers don’t work well as the brass transfers heat fast and well, and that solder pencil is at many hundreds of degrees. You will get burnt. I like to use a little more flux on long joints to help flow the solder, but basically you are touching the pencil (with a little solder on it) at one end, wait for it to melt into the joint and again, drag it along. If you have other soldered joints that you need to protect, you’ll need something to absorb heat and keep it cool. I just use some plumbers putty. It’s cheap, available everywhere, and works well. Sometimes it can be a pain to clean out of little nooks and crannies but a stiff bristle brush takes care of it. After the part is cooled, you can use a file to shape and rem
Best way? Have someone that is experienced with building brass kits build it. Or at least, have them start the kit while you watch. Take notes!! Have them sit with you when you take over. OR, just pay them and have them build the whole thing. Nothing hurts worse than boogering up an expensive kit.
I do my soldering with a torch as well, but my process is a bit different than Wayne’s. I don’t pre-tin my parts. What I do is flux the joint to be solderer with some liquid flux and a brush and then add a couple bits of solder with a pair of tweezers to the joint. I cut the solder into pieces with an Xacto blade. Small pieces of solder for small joints, and bigger pieces for bigger joints, like a corner joint on your caboose kit. Then I will heat the joint with a small pen type butane torch until the solder flows into the joint. Whenever possible, you want to solder from the back, or inside of your joint so it won’t be seen when the model is completed.
I’ve scratchbuilt two brass steam engines with this technique.
John.
My hope is someone here or on another forum will offer to build it for me. Its a fairly simple caboose other than cutting the parts from the sheet brass, and opening up all the windows, Then solder it all together. I would love to sit in and learn how to do it, but for now I would be happy just sending it to someone that has the knowledge to build it correctly Mike
I would recommend a fine-toothed jewler’s saw for cutting out the pieces. IIRC, the old Kemtron kits were made of pretty hefty sheet brass, not like the paper-thin stuff you get in the etched kits nowadays…[swg]