Garden Railway Forum

The boiler has been a real mission. I went for the classic wet everywhere firebox, to have at least built one once. Using one grade of silver braze. Doing all the brazing in low-light to keep an eye on not getting the job overheated on subsequent brazing operations. I had to order-in Sievert's excellent Cyclone burners. These are the only burners that can remain alight in the firebox. I'm using the smaller Cyclone burner for steam testing the boiler at the moment.

Trying out different firehole rings. Went with the smaller one, which still gives a generous opening



Dry-run of the Firebox pieces




Firebox inner, pieces riveted together




Firebox Inner with brazing partially complete, with tubes and tubeplate installed for the next brazing operation




Firebox inner complete, with tubes brazed in




Making bushes for the backhead and trying-out the bought-in "3/16" x 40 tpi plain water gauge" I buy from Macc Models




Starting the hole for the turret / dome bush. Using a holesaw with the pilot drill replaced by solid steel rod. This really helped my flimsy bench drill




Once the above cut had become continuous it stopped cutting, and I was cautious of a dig-in with all that soft copper. I drilled many holes to break-up the cut, and it was a success.



Finished at last without any drama




Hole needs filing to finished size. Before the drilling, I marked-out the finished size and position




Looking through the tubes




This low sited bush will take the blower valve. A small pipe will draw steam from the dome.




Dry-run of firebox inner and backhead in the boiler shell






Foundation-ring pieces. The backhead has already been brazed into the boiler shell




Boiler fully brazed with bushes plugged for testing






My brazing bench in the garage with window boarded and curtained for daytime brazing sessions




Boiler fully immersed in citric acid pickle bucket




Pretty in pink! I love the natural copper colour




Boiler, full of water, in the fridge. I cooled it all down so that only a little heat would be needed to pressure test the boiler. I use the gentle warming method to expand the water. No pumping required! It's proved to be a controversial method.




On the garage workbench, ready for testing. Test gauge (0 to 86 PSI) fitted to blower bush.




I decided to paint the backhead end to cover a multitude of sins! The fumes were so foul, I took my mini oven outside to bake the Engine Block enamel (rated to 500 deg F). My last baking was at 150 deg C, which is a little above the steam temp at 40 PSI




Finished paint




Out on the railway for the sun




Backhead

Hi Dave, fantastic work as usual. I could feel the tension using the hole saw to cut that dome hole (I would be very ready to reverse the handle on the drill feed). What will be the approx. size of the grate? you've certainly got enough tube area for what appears to be a very short grate. A freshly built boiler always looks great after pickling, and yours is no exception.
I think your "contraversial" boiler test method comes about from some thinking you have to boil the water before any pressure increase, no understanding of basic hydraulics.
Glad your boiler passed its test.
Grant.

LNR:122612 wrote:Hi Dave, fantastic work as usual. I could feel the tension using the hole saw to cut that dome hole (I would be very ready to reverse the handle on the drill feed).

Thanks Grant. The only support it had was the backhead Sellotaped on

The grate's about 1" x 2.5"

Might as well have an as easy steaming boiler as possible

Thanks for sharing the build with us all so far Dave, you make it look so easy to build!

Can I ask why you have gone for three tubes?  Your design is similar to the Riverdale boiler I have which only has two.

tom_tom_go:122614 wrote:Thanks for sharing the build with us all so far Dave, you make it look so easy to build!

Can I ask why you have gone for three tubes?  Your design is similar to the Riverdale boiler I have which only has two.

Two weren't enough. I did the math, and wanted something on the upper end of the usual acceptable ratio. It was a while ago now.

Best wishes,
Dave

As the test pressure gauge was still attached to the boiler I thought I'd make the safety valve next.  It's the ball bearing type, but not a pop-valve.


This is the top of the safety valve, the holes were marked out and centre punched under my bench mounted illuminated magnifying glass, and drilled in the bench drill.  The holes are 1.3 mm dia.




Testing the safety valve, using the small Sievert cyclone burner

I have been slowly plodding along with the construction, it's been a lot of fun though. At the moment I'm pushing for a steam test soon. The chassis is on the workbench, I'm getting it all set right, I love all the fitting. There was too much sideways play in the axles so I added grubscrews to the spacers that sit between the wheels and axle bushes, these allowed me to adjust their position to reduce play. Then I had the bright idea of oil blackening these parts. They came out a lovely shiny black.



This is the part being blackened in the video


Axle spacer fitted with grub screws


Happy New Year

Hi Dave, Happy New year to you too.
Your blackening process is one I've used for things, but never found it very durable. Some actually chipped off. Have you any experience of this?
Grant.

Have you tried chemically blackening metal Grant?

LNR wrote: ↑Tue Jan 02, 2018 12:01 pm Hi Dave, Happy New year to you too.
Your blackening process is one I've used for things, but never found it very durable. Some actually chipped off. Have you any experience of this?
Grant.

Hi Grant, I've used it a bit. Look at this image, I made these die holders for my Unimat 3 lathe in about 1990, not sure when I blackened them but maybe when I restarted the hobby in 2005. The smaller has worn because I hand thread with it often. I'd say it was an ideal finish for loco parts with no great thickness and no chipping.

A while ago I tested the chassis on air power, the first from a football pump, and then from my car tyre. I was so happy with the slow running on the tyre compressed air that I'm speeding towards a steam test





This project is two years old now

Great slow running Dave, a credit to your fitting work. Bet your dying to get on with the project now.
Re the metal blackening, and not wishing to hijack the thread, but when you used the word blackening
that put me on a different track. As an antique clock collector, I have cause to "blue" many steel items and the colour is really long lasting. Seeing you quench in sump(?) oil I thought you were looking for something different.
Grant.

LNR wrote: ↑Wed Jan 03, 2018 3:20 am Re the metal blackening, and not wishing to hijack the thread, but when you used the word blackening
that put me on a different track. As an antique clock collector, I have cause to "blue" many steel items and the colour is really long lasting. Seeing you quench in sump(?) oil I thought you were looking for something different.
Grant.

It's really dirty 4-stroke lawnmower sump oil, plenty of missed oil changes, so plenty of carbon.

Here's a summary of photos filling the gap from Feb '17 until now.

Safety valve with new whistle valve


Whistle valve, and turret for pressure gauge, plus one accessory


Instead of brazing, I Loctited the nipple to the blower pipe


Smokebox sealed


The loco prior to my April UK trip


Smokebox door locking bar


Machining the chassis mounted port blocks


Cylinders and port blocks


Smokebox with mounted reversing block


Machining the reversing valve


Piston assembly


Prototypical openings in buffer beam; I passed the pistons through them


Setting the port openings


Complete reversing valve assembly with steam inlet and exhaust, plus big bucket dead leg lubricator


O-rings in port blocks, small port is steam, large is exhaust, optimized for forward running; we'll see if it makes a difference in real life


Regulator body


Outside on the line with the large regulator handle


Halfway into the blower pipe elbow


Elbow with fittings and blower pipe


Blower pipe fitted to smokebox


Merry Christmas!

Great little engine. I like the unusual way the cylinders are coupled to the driverods. Looks a bit like a rack railway locomotive.

Prototypical openings in buffer beam, so that's why there are big holes!

I never knew why, yeah laugh it up.

This engine is lovely and a joy to read about it's creation.

Wow! That's so good. I do admire your engineering skills - and envy them.

Rik

daan wrote: ↑Fri Jan 05, 2018 10:57 am Great little engine. I like the unusual way the cylinders are coupled to the driverods. Looks a bit like a rack railway locomotive.

Thank you. It would have complicated things angling the cylinders and all downwards. It's a bit of an oversight too. I was going for attachment at the rear crank pin, but was concerned that I wouldn't get enough "waggle'. Let's see how it looks when I make the footplate.

tom_tom_go wrote: ↑Fri Jan 05, 2018 12:32 pm Prototypical openings in buffer beam, so that's why there are big holes!

I never knew why, yeah laugh it up.

This engine is lovely and a joy to read about it's creation.

Thank you Tom. It's just my guess, but the holes are in the right place

It's getting really close to a steam test, with a blowtorch in the firebox!

ge_rik wrote: ↑Fri Jan 05, 2018 1:30 pm Wow! That's so good. I do admire your engineering skills - and envy them.

Rik

Thank you Rik. I really enjoy it. I just don't seem to lose interest anymore, unlike when I was young. I admire your work too. And, (fingers crossed) I hope this loco gives the slow/smooth performance that you have found lacking in comercial live steam locos