THE BOILER
I carried on with the grate and ashpan and fitted the damper. This opens a bit wider than the original, although
I don't think it will make that much difference.
The next odd job was the packing on the piston glands. I'd been putting this off as I knew it was a problem. The
original design used PTFE packing and a bronze ring was between this and the gland bush. It seemed a good idea at
the time. The ring would compress the PTFE and do a good job. It would have, if I'd used enough packing, but I
didn't and so it had to come apart.
Fine, except there is no way of withdrawing the bronze ring stuck well and
truly up inside. So there was nothing for it but to undo all manner of bits including the cylinder end covers.
Needless to say the rings have now been cut off. I put in new packing and did up the gland nuts with a 'C' spanner.
Then I made up a little clip to locate in the slots and stop it from coming undone. There was plenty of material to
tap a thread in the end covers. The whole thing finished and now it is very stiff to move the wheels round. Still,
as they say, once round the track and all will be loose!
Another job was to
make the whistle. It made a change and I went through my off cut and scrap boxes. I had a piece of very thick
walled brass tube from my clock making days, a small lump of some sort of gun metal and some hex bar. I elected
to go for a bell whistle as I'd spent a whole week trying to make a decent chime one, which had not been too
successful. I'd made a bell one for my Kerr-Stuart which worked well, so long as I didn't give it too much steam.
I'd used 1" diameter copper but that looked a bit small, so now I've probably gone oversize as can be seen from the
ruler in the picture. When polished, it looks quite nice but the different metals do show and when gun metal gets
hot, it goes much darker than the brass.
This time I'll spend more time getting the steam supply through the correct
pipe size, but that will come when I've got much nearer completion. The whistle blows a perfect 'D', which is pure
luck so when in steam it will be about an 'E' or E flat. It's roughly a semi-tone difference. I have an electronic musical instrument tuner which proves very
useful when trying to make a chime one.
I thought I'd better make a bracket as well and as the whistle is quite
heavy, it needed to be a substantial one. As I had time on my hands, I made it quite a fancy one. Bit of a job
holding the three bits in place to solder and worse still to clean and polish afterwards. When I mount it on the
spectacle plate, I'll use domed brass nuts and I'm considering using the bottom hole as a way through for the steam
pipe as well as a mounting bolt.
Today I picked up my boiler. I say picked up but it weighs 154lbs or 70kgs. It's on the hoist ready to lower into
the frame to see the fit. I'll then take it out again as there are several things to do to it which are easier
when off the frames.
18 November 2003
It was almost a perfect fit. The washout plug bosses were just a bit oversize so I had to
file a bit off the footplate on one side. The welding is a little more pronounced on one side of the firebox base
which gives the boiler a tilt. So a bit of fiddling there.
The first job will be to make a
fusible plug. This is new ground for me, but I gather all steel boilers are so fitted. The picture shows the view
up inside the firebox of the plug socket in the roof. First problem is that all threads are BSP which means I don't
have the taps and dies. Fortunately, they are almost all the same size; 3/8". That is apart from the fusible plug. So,
rather than buy a set just for one hole, I'll try and adapt an ordinary blanking plug from the plumbers. I hope I
can get away with just dies and taps and not have to cut any threads on the lathe. 19 TPI is not an easy gear train
to set up and my gearbox doesn't cover it.
I was surprised to find that the plugs were hard to find and most merchants
only sold brass ones. So I ended up making my own.
I've shown a picture of
the boiler in the frames just to give an idea of the size really but also to locate the holes in the smokebox for
the exhaust and steam pipes. Although I made the saddle to the same height as the drawing, it looks just a little
high giving the front end a lift. One major problem has arisen. The exhaust connects on the back of the cylinder
and the drawing shows a block setup with a 1" square steel block bolting on the inside to make the pipe connection.
The problem is that there is only about 1-1/8" gap, so not enough room for a bolt to go through the block and into
the cylinder. So, small pause while I sit down and think of way round it. The drawing should of course,say, fit
before attaching the cylinders to the frames. There is no way I'm going to undo all the running gear and remove
the cylinders. I've blanked off the first water inlet hole at the front of the boiler,as this is for a one-day-job
when I have ideas about adding a steam pump for the water supply.
When I looked at the backhead to think about fitting
the site glass, I found that the Lloyds' insurance mark was right where the top hole should be! So for a change, I'm
going to fit a pair with the top connection being on the outer curve part. This will show water level right up to the top.
It seems strange to just drill a hole in the body and tap a thread where it's needed. Copper ones always needing a bush.
Instead of BSP thread, I used a metric tap with a pitch of 1.25, which is about 20tpi; not far from the 19 of a BSP.
2 December 2003
This is my solution to the exhaust connector on the inside of the cylinders. The original is a 1"x1"x2-1/8" block of
steel and the steam way is a 1/2" hole drilled from side and top to meet and then the pipe is connected to that with
another flange. A simple cut off 15mm elbow from the plumbers provides a better steam way without the back pressure.
I will also connect the pipe by soldering it in place and avoid making another flange. Unfortunately there isn't enough
clearance for the bolt heads, so I'll use stand-off washers and then there is enough room for the bolt heads where the
tube is waisted. The drawing specifies 5/8" tubing but I'm using 15mm plumbers' tube which is easy and cheap to buy.
There is little difference in bore size.
After all that I found that although there was room for the bolt, it was not possible to get a spanner on both;
just one. There is nothing for it but to take off the cylinders. That is going to be quite a job because of all the
connections to the valves and running gear.
I did try cap heads, but even a shortened allen key wouldn't go in. So
I had to add an extension and a flange after all because I need to be able to fit the steam pipe with the boiler
in situ. I hate making flanges.
It was quite a quick job to remove the cylinders after all, and the whole job was
done inside an hour. Even with them off, it was still difficult to get a spanner on properly.
I turned and fitted the regulator bronze bushes to the backhead and front tube plate because it was easier to drill
and tap with the boiler off the frames and in a vertical position. I cleaned the outside of the boiler and gave it
a coat of etching primer to stop any rust which might occur when under the cleading and not seen.
I also bought
a commercial lever ball valve which I'm going to use as a regulator.
One of the problems when boiler testing is that the regulators often let water passed. I like the Stroudly type and
on my Kerr Stuart I blank the regulator off in the smokebox, which is quite a job. These commercial ball valves are
perfect for the job and never leak. I know a commercial set up where one has been in almost daily use in the summer
for the last two years.
I have also bought the smokebox door and ring castings. When the ring is turned to size I'll
be able to rivet it in position with the boiler off the frames. Then I can place it in the frames, hopefully, for
the last time.
I was horrified at the price rise in the castings; £21+postage in 2001 and now £47! The chimney has risen by a similar
amount and with vat and postage comes in at £75. I haven't bought it yet. It's a question of time in building one
up from pieces or saving time and paying for it. I'll let Christmas go by first and see how things are then.
The chimney has a bore of 2.25" but by working back from area of grate etc it should be about 1.5". There is also
no petticoat pipe and the blast nozzle is very close to the choke. I understand this is how it is with a traction
engine. Time for a think. Next update will be in the new year.
13 December 2003
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*************
The next odd job was the packing on the piston glands. I'd been putting this off as I knew it was a problem. The
original design used PTFE packing and a bronze ring was between this and the gland bush. It seemed a good idea at
the time. The ring would compress the PTFE and do a good job. It would have, if I'd used enough packing, but I
didn't and so it had to come apart.
Fine, except there is no way of withdrawing the bronze ring stuck well and
truly up inside. So there was nothing for it but to undo all manner of bits including the cylinder end covers.
Needless to say the rings have now been cut off. I put in new packing and did up the gland nuts with a 'C' spanner.
Then I made up a little clip to locate in the slots and stop it from coming undone. There was plenty of material to
tap a thread in the end covers. The whole thing finished and now it is very stiff to move the wheels round. Still,
as they say, once round the track and all will be loose!
Another job was to
make the whistle. It made a change and I went through my off cut and scrap boxes. I had a piece of very thick
walled brass tube from my clock making days, a small lump of some sort of gun metal and some hex bar. I elected
to go for a bell whistle as I'd spent a whole week trying to make a decent chime one, which had not been too
successful. I'd made a bell one for my Kerr-Stuart which worked well, so long as I didn't give it too much steam.
I'd used 1" diameter copper but that looked a bit small, so now I've probably gone oversize as can be seen from the
ruler in the picture. When polished, it looks quite nice but the different metals do show and when gun metal gets
hot, it goes much darker than the brass.
This time I'll spend more time getting the steam supply through the correct
pipe size, but that will come when I've got much nearer completion. The whistle blows a perfect 'D', which is pure
luck so when in steam it will be about an 'E' or E flat. It's roughly a semi-tone difference. I have an electronic musical instrument tuner which proves very
useful when trying to make a chime one.
