Kozo K-27 Boiler
Part B
This disk of about 2"
diameter will be
used to form the firedoor ring. Two slices will then be made in it to
create the two semicircles that will form the top and bottom of the
firedoor opening. I'm waiting on the copper strip that will form the
firedoor ring. September 2, 2023.

Here we see the throat
sheet mounted
on a fixture that was bolted to a rotary table to true up the cradle
that the boiler shell will rest in. The sides and bottom have also been
trued up on the mill. The three large holes in the copper will be used
for the 1/4" staybolts. The two smaller holes at far left
will be
used to secure the mudring while it is being soldered in place. This
step also required the machining of an #2 MT plug with 1/8" locating
pin so that the wood fixture could be accurately centered on the rotary
table. The throat sheet is now ready for final assembly and soldering.
September 4, 2023.

The firedoor ring was
formed out of a
copper strip approximately 3/4" x 6" long bent into a ring of about 2"
diameter. The flats were cut from the bronze ring a couple photos up
and then soldered to the ring. September 9, 2023.

Today was spent making a
wooden
backing plate for the front tube sheet and laying out the tube
locations in the two tube sheets. These will be bolted together on a
faceplate so that the tube holes can be bored simultaneously in both
sheets. The tubes will be 3/4" copper pipe with 10 tubes running
through the boiler. September 10, 2023.

My grandfather's old
South Bend lathe
didn't come with a slotted faceplate so I had to pick one up on epay.
This one isn't in to bad of shape and was fairly reasonable. September
10, 2023.

Boring on the lathe with
the faceplate
didn't work out since the swing of the lathe needed to be about an inch
larger. Instead I am using a boring head on the mill. Here we see the
first two tube holes opened up to accept the 3/4" tubes in both the
front tube sheet and the firebox tube sheet.. The third hole has been
drilled about as large as I want to go and will be bored to the final
size. Drilling alone isn't an option since the holes are so close
together and large drill bits might deform the hole next to the one
being drilled. Just seven and a half more to go! September 17, 2023.

Half of the tube holes are now bored to fit the 3/4" tubes. Only five
more to go. October 1, 2023.

The ten tube holes have
been bored in the front tube sheet and the firebox tube sheet. October
8, 2023.

The front tube sheet has been left on the table since six more holes
need to be drilled and we don't want to lose our reference location.
October 8, 2023.

The front tube sheet
after some
deburring of the holes. The outside edges of the sheet will need to be
machined before any soldering of the firebox. October 8, 2022.

Additional holes have
been added to
the front tube sheet. The outer four holes will have studs added to
secure the smokebox to the boiler. The four small diameter holes will
be used to attach some support ribs to the backside of the sheet. The
other two holes will be for the fittings for the blower outlet and the
steam outlet. October 15, 2023.

The front tube sheet was
chucked up on
the lathe and the outer diameter machined to the dimension of the
boiler tube. This will make for a nice machined surface to solder the
tube to. I'm waiting on some 1/4" x 1" copper strip to construct the
ribs that will go on the backside above the tube holes. October 21,
2023.

On the mill one of the
firebox sheets
is getting a hole bored for the firebox door. Next will be drilling of
all the staybolt holes. October 22, 2023.

The firebox back sheet
and the
backhead have been match drilled for ten staybolts and the hole for the
firedoor ring. The firebox back sheet has also had all of the outer
edges machined and the staybolt holes have threads. The backhead has
additional holes for the throttle base, blower bushing, water gauge
bushing and a support rib. The small holes in the bottom of each sheet
will be for the mud ring. October 28, 2023.

The ten staybolts and the
firedoor
ring have been silver soldered together to complete this piece until
final assembly. October 29 , 2023.

The outer edges of this
sheet have been machined and the three staybolt holes are threaded.
November 1, 2023.

The outer edges of the
backhead have been machined to provide a smooth surface for the outer
shell to attach. November 4, 2023.

A 1/4" thick support rib
has been
added to the top of the backhead to provide support since there are no
staybolts this high. November 5, 2023.

The staybolts have been
soldered in place for the firebox tube sheet. November 5, 2023.

One of the ribs for the
front tube
sheet has been made. A second rib will need to be made for the very top
but I ran out of 1/4" stock. November 5, 2023.

The two 1/4" ribs have
been soldered
to the back side of the front tube sheet along with the four smokebox
mounting stubs. The next step will be to fabricate the boiler shell
sections. November 11, 2023.

The front boiler shell is made from
0.080" thick copper and has been trimmed to about 18" x 10.250". Layout
work to locate the various appertunances is shown above. Next will be
the rolling of this shell. November 18, 2023.

The front boiler shell has been
annealed and rolled to the required diameter of about 5.75 ".
This section is approximately 10.25" long. November 25, 2023.

The middle boiler shell has been formed and is approximately 6.5" in length. November 26, 2023.
The outside firebox sheet is a semicircle that is about 6.75" in length. November 26, 2023.

The front shell with the seam riveted together in preparation for silver soldering of the seam. November 26, 2023.

The front boiler shell with all holes bored for the various fittings.
From front to back we have the water fill bushing on top, water inlet
and running board mount down low, handrail bosses up high and finally
the steam dome base. The shell is shown in about the approximate
location on the frame. All of these fitting will need to be silver
soldered to the shell. December 10, 2023.

All of the fittings have been silver soldered to the shell. December 26, 2023.
A ring has been added to the rear of the shell which will be used to connect the middle shell. December 29, 2023.

The middle shell has been temporarily
joined to the front shell to provide a visual of how this might look on
the frame. Further work on the middle shell will be next on the list.
December 29, 2023.

The outer firebox shell with the manifold bushing, generator base and studs for mounting the outer jacket, December 30, 2023.

The middle boiler shell with bell
base, handrail mounts, air compressor mount and running board mounts.
This will need to be cleaned up in an acid bath. December 31, 2023.

All of the completed boiler
sub-assemblies for this segment of the project. The next segment will
be the completion of the boiler. January 1, 2024.