Building Kozo's New Shay locomotive

[crueby]

Rivets usually are round as you mention, mine came out with square head since I started with a square piece of copper cut from scrap sheet. It would look a little better round but works just fine, and being inside it won't show anyway so I skipped that step.

I am using cutting fluid on the copper cuts - before taking pictures am wiping off the oil/chips to show the part better. Before soldering I am cleaning off all the oil so it won't interfere with the solder. Cutting it dry makes it stick and grab at the cutter, unlike brass which I cut dry most of the time (except fine drills and taps)

 

[SilverSanJuan]

Todd, that is a great set of photos! Did he do a build thread for that engine? Different model but a lot of commonality between them. Thanks for the link.

I don't think there is a build thread for it. But, there are two other guys who've also built the A3 in 3/4" scale on Flikr. I can send you the links if you'd like.

Todd

 

[crueby]

Quick update - got the first boiler shell section silver soldered up today - took a couple sessions to get all the joints done, some of the joints took a couple of tries. This was my first time soldering up long joints, took a couple experiments to figure that out, wound up using both torches to put enough heat in quickly - that worked very well. First tries with one it was hard to get both the shell and the joint strip heated up together. In a couple of places I went back after pickling/brushing to redo a spot that did not get solder flowed in. Right now it looks like I got everything - visually it looks like full coverage.

Also took some more wood scraps and made up bending forms for the inner and outer firebox sections. Kozo did the bending over pipe sections, but I have had better luck making a full length form from wood (having a lot of offcuts from furniture projects and a bandsaw came in handy!). Next time will show bending up the firebox sections....

Chris

 

[crueby]

Busy day - went ahead and formed the rest of the boiler shell sections. The first picture shows the conical forward part of the boiler after one pass, got that far and it work hardened, went back for more annealing. Took two more passes to get it fully formed and trued up.

Second photo shows the second pass on the outer firebox shell - took one more pass after this one to get it formed fully where it transitions back to straight at the bottom.

Third photo shows all the sections as they stand now - I got the conical section soldered up (has a joint strip down the inside just like I showed on the first boiler section the other day).

All the sections are close to fitting together, the joint rings just need a little filing to let the other ring sections to seat tightly so the solder can wick between them. Major progress today, going to be a couple days before I can get back in the shop again.

 

[SilverSanJuan]

Beautiful work! How did you form the conical section? Was there a template for it?

Todd

 

[crueby]

Beautiful work! How did you form the conical section? Was there a template for it?

Todd

In the book he gives the measurements to lay out the shape on sheet metal, which I used to make a cardboard template first, and cut the metal to that. Here is the picture of the sheet pieces before bending, the one in the upper left makes the conical piece.

For this one I did not make a wood form, but bent it around a pipe, angling the piece as I went. The final shape is a cone, but with the ends angled so that the bottom edge where the joint is runs at a right angle to the ends. That piece was tricky to shape without the form, but not bad. I used the round forms from the end plates as a guide to getting the ends round. To get the joint pulled up tight to rivet it I put rings of steel wire around the cone and tapped them down like barrel hoops to draw it up.

The really tricky one was the firebox sheet, since that one is 3mm thick rather than the 2mm everywhere else. That extra thickness made it a lot tougher to shape and keep the two sides straight and parallel in the finished piece. Took a couple extra anneal steps before that shape came out well - fortunately copper is forgiving to reshape a bit as long as it is annealed. Came in handy the one time I dropped one of the sections and bent the edge in a little!

 

[crueby]

Got the fittings for the outer firebox sheet drilled for and soldered in today. Also made the support ribs (rectangular bronze, milled down from round - first photo) that hold the steam bracket base on - this base has the steam manifold and upper engine supports later on, so it requires bracing inside the boiler to take the added weight. Kozo designed it so the manifold is attached directly to the boiler so it gets warmed by it. The ribs were drilled/tapped for screws to hold them in place for soldering.

Second photo shows it all soldered up.

Third photo shows the back plate test fitted - ready for fine tuning the joint with a file to get a tight fit. After that, will fit the middle section of the boiler to the outer firebox and solder them together. So far so good!

 

[crueby]

Another day, another section on the boiler. Got the outer firebox section and the parallel middle section joined up and silver soldered together today. Took a little filing/tweeking of the joint ring to get it to seat tight, then got the throat piece fitted underneath and screwed to the two sections to hold it all for soldering. Next up is to fit the conical front section on. Actually starting to look like it will be a boiler when it grows up...

 

[SilverSanJuan]

Nice work! It is indeed starting to look like a boiler.

Todd

 

[crueby]

Got the conical section soldered on - looks like I am hitting the limit on the torches I have - with this much mass and surface area it is wicking away the heat almost as fast as I can apply it. Got some missed spots that need another pass, most of it took - just.

I am looking around at other torches, anyone have any suggestions for an economical way to go? Has to be available in the US (seen some nice ones that are common in UK/Europe but not here). Prefer to go with something that could hook up to a standard 20lb propane tank, since I have one of those (current model threads on it, they changed them a few years back). I've seen some that are intended for roofing work that look like they put out a lot of BTU's, could heat a large area up while I could zero in with the mapp gas torch for the joint being soldered. Anyone use that type? Better way to go??

 

[littlelocos]

Really-REALLY nice work! Absolutely beautiful.

 

[SilverSanJuan]

I've read that a Sievert torch with a rosebud on it works really well.

Todd

 

[crueby]

After great advice gotten here and over in Questions forum, found a sievert torch kit on sale for a reasonable price. While waiting for that, I am going ahead with the fire tubes and firebox assembly, pics later today....

 

[bouch]

Got the conical section soldered on - looks like I am hitting the limit on the torches I have - with this much mass and surface area it is wicking away the heat almost as fast as I can apply it. Got some missed spots that need another pass, most of it took - just.

I am looking around at other torches, anyone have any suggestions for an economical way to go? Has to be available in the US (seen some nice ones that are common in UK/Europe but not here). Prefer to go with something that could hook up to a standard 20lb propane tank, since I have one of those (current model threads on it, they changed them a few years back). I've seen some that are intended for roofing work that look like they put out a lot of BTU's, could heat a large area up while I could zero in with the mapp gas torch for the joint being soldered. Anyone use that type? Better way to go??

View attachment 72862

Next time you need to silver solder to the boiler, start insulating the parts that don't need to get heated up. I remember hearing somewhere that if you bury the boiler, except for the part you're working on, in kitty litter, it works as a good insulator so the heat doesn't flow down the entire boiler.

Kitty litter is basically clay, so it makes sense to me that it would work.

Might want to do some googling/research to see if I'm remembering correctly or if I'm nuts...

 

[crueby]

Next time you need to silver solder to the boiler, start insulating the parts that don't need to get heated up. I remember hearing somewhere that if you bury the boiler, except for the part you're working on, in kitty litter, it works as a good insulator so the heat doesn't flow down the entire boiler.

Kitty litter is basically clay, so it makes sense to me that it would work.

Neat tip - have to try that. At least with the basic cheap clay litter - some of the newer stuff who knows what it is.

Might want to do some googling/research to see if I'm remembering correctly or if I'm nuts...

Seem to recall times I may have been BOTH correct AND nuts...! :hDe:

 

[crueby]

As I mentioned earlier, while waiting for the bigger torch for the main boiler shell assembly, I went ahead with the firetube assembly - three firetubes and the firebox. First photo shows the tubes soldered into the front firebox plate - up at the top out of the shot I had the front endcap slid into place on the tubes to hold them in alignment.

Second shot shows that assembly screwed into place on the firebox, and then soldered up. The front endcap is still there at the left end, that is not soldered on yet, just using it to hold/support that end of the tubes. It gets soldered in place last, since it has to go on from the outside of the outer shell.

The third photo show the back firebox plate being checked for fit - spent some time tweaking the shell and tuning with a file to get a tight fit. By shining a flashlight from inside, I could see any gaps and where the two pieces were touching - file down the touches till the gaps go away. On the first plate I'd just hold it up to the window, but on the second needed the flashlight to get into the corners.

Last shot shows the plate fitted and screwed into place, ready for soldering up.

By then, was getting a little tired, and got to the 'put down the tools and go do something else before you do something stupid' point. Probably will solder this up tomorrow, or may wait for the other torch - getting a lot of metal in one place now, that firebox shell is a lot thicker than the outer boiler shell, and the front end took a while to heat up.

After the firebox and outer shell are all soldered up, the next step will be to put the two assemblies together and fit/solder on the boiler backplate. Not bad progress lately - happy with how it is going so far!

 

[SilverSanJuan]

Looking great! How are you ensuring that there is no twist in the firetubes from front to back?

Todd

 

[crueby]

Looking great! How are you ensuring that there is no twist in the firetubes from front to back?

Todd

Hi Todd,

The tubes are a tight fit in the holes, and keeping the endcap on the other end keeps the tubes running together and not splaying out or in. Did some careful sighting down the length to make sure they were straight before soldering the firebox end. When soldering, the assembly was vertical, and hung on the edge of a vertical firebrick (happened to be about the right height, just needed a small shim). The endcap and the firebox sheet had enough edges/fittings to make it easy to sight along it to make sure it was square and not twisted. If the tubes were a sloppy fit that would have been a lot harder - I milled them out till the tubes were a tight force fit.

Chris

 

[crueby]

Well, gotta love having the right tools for the job. Got the bigger torch today (Sievert), and it really does the job. I probably could have gone for a slightly smaller nozzle, but this one had the full kit (regulator, hose, torch, end) at a reasonable price - it is one of what they call a roofers detail torch. I used it to heat up the whole assembly close to soldering temperature - got there pretty quick - then turned that one off and used the smaller torch to put the final heat on the joints. These types of torches are most definitely an outside tool - no way would you want to do this indoors (unless you have a MUCH bigger shop than mine, I guess!). Worked out great - redid the couple joints on the outer shell that I could not finish before, and also soldered up the backplate on the firebox (no new pictures, looks just like before just with solder). The pieces pass the light and water leak tests, looks like full coverage - best I can do till static pressure testing can be done. The pieces are soaking in pickle again right now, will get them cleaned up good and ready for fitting together next session.

Thanks to all those who gave me advice on torches and techniques, here and in the questions forum!

 

[SilverSanJuan]

That's great to hear. Look forward to seeing your continued progress. You'll be performing a hydro in no time.

Todd