Sisyphean

[David]

I had time to put a fire in the red loco this afternoon so I filled it with hot citric acid, put the dome cover back on and lit it a fire.

Consider there is no front right cylinder drain, the regulator may be putting more water in the steam circuit than it should. At some point when I was trying to run it (after a few hours of just keeping the boiler hot) I heard a nasty noise and the loco jolted. The loco then didn't want to start without a lot of steam and eventually I noticed it didn't want to tick over on low steam and hesitated at the same point each revolution of the wheels. I guess I'm lucky the cylinder cover didn't shoot off but I'm going to have to redo the valve timing and hope the grub screw hasn't scored the axle too badly making it difficult to move the stop collars like happened last time (yes, there was a last time when a valve rod broke and dug into the ballast - my fault for using 15% silver solder on steel - I didn't know that didn't work at the time).

I checked the injectors before putting them back on and had to clear a flake of crud from the LHS steam cone. That injector seemed to be working well when I first tried it after the water level had gone down - recall there are leaks everywhere on this thing - but it is now like the RHS was last time I ran it and will not pick up cleanly above 80 PSI. It sort of works and as the pressure comes down it gets better, but 2 injectors working only up to 80 PSI is not usable in my opinion. I'm not willing to put new ones on until I know the boiler won't be pushing stuff into them though.

There really are leaks everywhere now. The inlet T on top of the boiler is particularly bad and probably needs replacing with a new one with an oversized thread. This has been happening for at least a year but is much worse now. Water is constantly dripping from the cylinders. I'm guessing the system getting flooded with citric acid after the regulator started leaking had a detrimental effect.

Water and steam shooting out from every connection made it look like a real one after they stopped cleaning them, with a calcium looking crud covering everything. On the boiler it was a dirty chalky colour but on the running boards as the water evaporated more slowly it was more like the crystals I was seeing around the blowdown valve when I tried to clean it last year.



The gauge glass is getting a lot of air bubbles, and the safeties don't seat any more and start releasing steam at about 40 PSI. The blower did immediately get blocked but then cleared itself after a while and seemed okay after that.

That all sounds like what Ross said to expect with newly softened crud getting flung around so I'll give it a run before worrying too much.

One unexpected result was that the regulator handle was a lot hotter than usual. That could be due to a constant stream of steam hitting it from the turret bush. I noticed this happened to a lesser degree last time the turret was taken out and replaced.

To finish up I did about 5 cycles of blowing down and filling up, dropped the fire, and blew it down to empty. Then I filled the boiler with compressed air and sent that through the injectors and blower and gauge glass drain.

I thought I'd see how the boiler held air so closed everything and watched the pressure gauge drop fairly rapidly. That's not a test of the boiler itself of course, I was looking at how the valves and fittings were behaving. Pretty badly was the answer. I'll do the same test again with blanking plugs for the inlet and manifold bushes to see if making some new fittings would help. I guess the boiler not being in steam with the metal really hot and expanded doesn't help.

I got it up onto the bench, carefully thought about how to take it apart because the steam chest and their covers are held on by what amounts to a pair of machinists jacks and I am always worried I'll break it, turned the connection on the steam pipe from the boiler the wrong way because I always expect the nut to be on the boiler outlet but its on the steam pipe to the cylinders so screws down to loosen, and got the steam chest covers off.

Here is the two jackscrews with the one on the right being the inlet T with the lubricator pipe going into it and the steam pipe out of sight. The screw on the left is solid and just there to hold everything together. It works pretty well but as I said I have to think carefully before taking it apart.



The steam chest cover was stuck on with loctite 567 and didn't want to come off. I tapped it with a copper hammer and the whole steam chest moved! I quickly realised that's because there's no studs holding it in place but it means the seal to the port face isn't very good.

Inside the steam chest doesn't look too bad. A bit of rust but it's not covered in it.

The timing does look to be a little off. I noticed some lost motion on the valve and the valve rod off to see how much slop there was. The hole for the pin has opened out from 4.76mm to 4.96mm. It is just a hole drilled in the steel rod with no bush. The pin has worn a bit so I'll have to make a new one of them too.

I decided I'd drill the hole out and put a bush in it. I opened it out using a 6mm endmill, offsetting the hole to try not to get any closer to the edge given there's not much metal there. I will make the bush about 0.002 over that assuming the end mill cut oversize. I have 4mm between the forks of the valve spindle so I'll make the bush 3.5mm wide with a thin 'top hat brim' on one side to help locate it.

I couldn't think of a better way to hold the rod, I don't have any parallels thin enough to clear the hole and the vise didn't seem to get a good grip on it anyway.



With the valve rod off I should be able to lift the steam chest (with valve) off and put some loctite on the face that sits on the port face.

[suctionhose]

Well David, you should be very pleased with all those results after cleaning! Disappointingly, I only got a bucket full dirty stuff and no valve gear to remake...



Ross :-)

[ettingtonliam]

When I suggested a citric acid treatment for your boiler, somehow I imagined that you would take it of the chassis to do, making it easier to juggle around and squirt a hose into its various intimate orifices to swill out the resulting mud/scale. Now, thanks to your leaky regulator you've managed to give your cylinders a citric acid bath as well. I don't know if they are iron or gunmetal, but citric acid is pretty aggressive with ferrous metals. I think a good cleaning out of the cylinders would be well advised, to get rid of the acid traces.

[David]

They are cast iron so I'll give them a pretty good flush.

I had a thought that it was probably all the oil and WD40 I'd squirted in the cylinders that helped cause the lockup, not just the water. While I was turning the wheels by hand to try and clear the system I could hear the stuff gurgling around because it couldn't come out a cylinder drain. But I was feeling no resistance so thought it would just go up the chimney like the water always does. And when it was running slowly there wasn't a problem either.

Now I can't understand how a piston lock-up could cause a valve timing change. Maybe it was the valve that locked up?

[David]

The only thing I could find wrong with the timing was that the valve didn't seem quite centred over the ports so I wound it back until it looked good. I noticed the tattered remains of an o-ring on the inlet T and when I looked at the other side I didn't see even that so I put new o-rings on it. I don't think I noticed them a few years ago when it was last in this state getting the timing sorted.

I couldn't get it to start for a long time and was pretty worried I'd stuffed something up (although I couldn't think what) but it eventually kicked over once I'd given the wheels a helping hand. It seemed to be running ok.

Things escalated quickly after that.

I thought "I should have fixed the cylinder drain given how far apart it was", so took it all apart again. This time I had to learn how the exhaust is fitted and luckily I have the Blowfly instruction book so I didn't break anything getting that out of the way. Then all the plumbing on that side, and the running board!

These drains have a 1/4x40 thread so I milled an 8mm counterbore and made a suitable press-fit bush with a thread already cut.

I make these a bit long so I can file them back to where the drain aligns nicely.



Obv I had to take the conrod off to get the cylinder off and there was a huge amount of play in the big end bush, and in both bushes of the coupling rod. I have replaced the front coupling rod bush so far and knocked the back one out but by that time I'd spent from 9-5 working on it so had had enough. I bored this bush out 0.001" at a time until it just went over the pin and then I was able to slide a 1/2" drill through it so I'll just ream the others 1/2".

The crank pins seem to have worn out of round because the new bush was bored on the lathe to size and was an ok fit but there is also clearance on it. I mentioned before the main crankpins have worn sort of like cam lobes.

[David]

I've continued to work on this problem each night this week but the only win I've had is the cylinder drain. I can find all of the linkages except the one that joins the two drains on this side, natch, but that's par for the course. The cylinder drain seems to work though.

Every steam valve leaks - blower, 2 injectors, whistle, and regulator. I'm not making a new regulator but if I can get it to run for a while without constant problems I'll make a new manifold with new valves. The current ones are always too hot to touch anyway and I've found commercial ones on other people's locos that don't get that way. I forgot to check the blowdown valve. I know the regulator is leaking because I can hear it in the smokebox.

I gave both clacks a suck test and they seem ok so the steam coming out of the injectors is from the steam valves. They are leaking where a screw goes into the body to stop the ball shooting all the way up but I guess I can thread seal that and hope the sealant doesn't get torn off and carried into the boiler. Or I could make news ones to the design of those on the B class which doesn't have the screw.

The bush in the valve rod and the new bushes on one coupling rod have done nothing to quieten the clanking but I now have a tight spot on what used to be a free running mechanism. I know that will wear out but it would have been nice if it got rid of a clank. It does mean I can't see if I've made the valve timing any better.

I tried to find a way to seal the thread of the top feed T piece using oversized threads and o-rings but the only thing that worked was a 19mm hex bar with a thread on it and an o-ring the flat part of the bar could press on. If you got the pressure just right the leak stopped. But I can't use that in practice because the T piece has to be able to screw down to the height the inlet pipes expect and then get tightened up by a nut, like gauge glass fittings get tightened onto the backhead. Even if I made a 19mm nut to ensure the o-ring was fully supported the pressure then travels up the thread of the nut and comes out on top because that's what happens with the current nut. I conceded defeat on that and smothered the threads of the T piece and nut with Loctite 567 and am hoping it doesn't find its way into the boiler and then the injectors. The thread in the boiler bush seems to be massively loose.

I guess the rate the pressure goes out of the various leaks is nothing compared to all the steam used when running but it is annoying. At least most of them can be fixed by replacing the manifold and valves which probably comes under normal long term maintenance on a loco that gets used for passenger hauling most months.

I've stuck some silicon around the hole in the floor of the smokebox but I haven't had time to fire it up again because work got busy! I won't have a chance until next week.

I'm still confused by the injectors not picking up above 80 PSI, and one of them started doing that the last time I ran it - December I think - so before the boiler clean. I thought if the clacks were leaking maybe the back pressure when the boiler was above that mark was not allowing them to work properly but I don't think that makes sense if they used to be able to start against the clacks (which are not leaking anyway). One of them has a constant flow of water through it because I removed the tap to remove only more point of possible failure so I don't think it's temperature either.

[osiris09]

I thought I was the only one that had these issues when working on a loco. I am glad to find out I’m not. I’m at the point in mine where I’ve had to pull the wheels off because they have 1mm of wobble and are too wide so bind on the track. Good luck with your rebuild. 🙂

[David]

Thanks, good luck with yours too, Osiris! Mine could do with a wheel swap to get the balance weights in the right place and new crankpins, and proper lubrication to the rear axles, but that's not happening.

You certainly feel like you achieved something if you can do a passenger hauling afternoon on half an injector and steam leaking from many places it shouldn't be. Then you drive someone else's loco and think 'it's meant to be this easy?'

[David]

While I was putting the red loco on its side to do the valve timing a couple of weeks ago I didn't notice the smokebox door flop open and get caught between the smokebox and benchtop. When I brought it upright I found this.



No surprise, anything that can go wrong will go wrong with this loco. Luckily I could bend things back into place without snapping the lower hinge.

I finished putting the cylinder drain linkages on early this morning when I couldn't sleep - my favourite time to do model engineering jobs I'm not looking forward to because I'm already in a bad mood! I had to make the link that joins the two drains on one side, but that was pretty easy because I'm past trying to make this loco look good so a strip of metal cut on the bandsaw and drawfiled to about the right size was good enough. The rest of the parts went on well enough although they're fouling the wheel flanges. Something will wear out - hopefully the drain operating rod which is just soft coat-hanger wire.

So it's back together enough for another steam test. I'd still like to take it to an event in a month or two so I do need to get on with it.

[David]

I was able to give the red loco a track test today and for the hour or so I was running it seemed to go well. It steamed well and both injectors worked right up to 100psi.

The cylinder drains worked more-or-less but I've run out of adjustment room to go in the direction I'd like so I'll just leave them as they are.

The leak on the top feed T is ok now after the application of a great deal of Loctite 567 to the threads a couple of weeks ago.

There was an unpleasant noise coming from the right hand side which I thought might have been a lack of oil in the steam, but the lubricator was full. I'm putting it down to the new bushes in the coupling rod until I can give it a longer run. There is a new tight spot on that side so I'm hoping that's it.

There is still a huge amount of limescale coming out and the gauge glass gets a lot of bubbles so I guess it's not clean in there yet. I filled it and blew it down a few times before I left loco, and had done so for about 20 minutes last Wednesday before an aborted trial run, so there's been plenty of blowing down going on. Wednesday's trial was aborted when I split the first set of points I went over, the loco went one way, the tender the other, the coupling pin bent and the water pipe from the tender was sliced open meaning no useful test could be done.

There was quite a lot of clinker even after that short run. I don't know if that's because I was using the blower every time I was going downhill or sitting in the station.

I tried Shawki's trick of putting vinegar in the tender. I was speaking to someone at the park and he said he uses vinegar in hard water areas. He said sometimes his injectors will only fill the boiler up to about half full before priming starts sending water down the steam pipes and cutting the injectors off. He uses the vinegar to reduce the priming. The same guy also filled his boiler with vinegar to clean it, left it in there for a few weeks. I was going to try that and had about 8 litres of vinegar in the trolley before I decided to try the citric acid.

Anyway, that's the best the loco has run for a very long time. I could sometimes get either decent steaming or an injector to go for an afternoon but almost never both and more often neither.

Another interesting thing that happened was the fire died while I was having a break during the rain (yes rain - I'd rather the rain than an afternoon's running right now). There was no pressure showing on the gauge, with the water about 1/4 of the way up the glass. I figured it was dead but put the blower on anyway and started pushing it back to loco. Within a few minutes the fire was back and pressure was rising, eventually back to full pressure in maybe less than 10 minutes.

[David]

I've given the loco another couple of runs and it's continued to behave! There has not been any hard passenger running though because we can't take passengers at the moment, so no real stress tests yet.

Still getting lots of bubbles in the gauge glass, not sure if that's still a result of the clean-out. I'm not worried about it though.

Not having a water tap on the right-hand injector means my youngest son (nearly 9) was able to drive it on his own last weekend - it was raining again so there was only one other loco on the track. I walked beside him and told him when to turn the injector steam valve on and off, watching the injector overflow to see when it was on/off because he can't turn the valve far enough in one go for some reason.

The various leaks in the boiler bushes have calmed down so that's good news. I've bought new steam valves for the injectors and a new valve for the blower and will make a new steam turret while I'm doing the one for the B class mogul. The current injector steam valves leak and are too hot to use without a rag so I bought some that I've used on other locos that I can operate with my bare fingers.

I tip a generous measure of white vinegar into the tender when leaving loco, and a bottle cap of tanblend water treatment. I have started trying to remember to blow compressed air through the injectors via the water inlets and then from the boilder via the gauge glass blowdown, which should also get the standing water that settled in the bottom of the firebox after the initial blowdown in loco.

So the loco can have its tanks and cab rear back now I think. If NSW doesn't suffer the same fate as Victoria has with the virus, I hope to take it to another track in a month or two that I've never had much luck at in the past, in the hope that all this maintenance and work will bring me a better outing this time.

[David]

Finished replumbing the cab. I was able to reuse all the old pipes because they only needed to be made shorter so the only new ones are the short elbows coming out the ends of the manifold.

The sight glass drain pipe is new, it's never had one in the time I've owned it.

[David]

I took the red loco out about a month ago and it is back to its old tricks!

One injector wouldn't work at the steaming bay, turned out to be a split in the silicone water pipe where one of the fittings pushes in. The edge of the fitting isn't sharp but it must just get stressed. I had a length of car vacuum hose in the riding truck that fit so got past that problem. Once on the track the other injector packed up. I assume it's blocked but I haven't looked yet.

There is a weekend gathering for this type of loco coming up and I've never gone before because the loco has never been reliable enough to bother traveling with but I thought I'd try and get there this year given I can usually get few hours out of it now.

In anticipation of that I decided to put a drain into the tender, something I've been "getting around to" for years. I flipped it over on the bench and saw two of the bolts holding the tank to the chassis had sheared off, then gave the wheels a roll to see how the bearings are holding up and one of them was wobbling around...

I found some replacement bolts (brass M5 I think) and took the wheelset off. One end of the axle where it sits in the doubled bearings inside the axlebox was bent and the motion caused by this meant the other end had a step worn in it. So I made a new axle yesterday.



That's the new axle in place and a 1" hole drilled for the drain. I put some sort of cable tidying spiral around the water hoses to try and stop them getting abraded as they rub against the various metal bits they're next to. Even the new hose already had rubbing marks on it after a single run. I'd only thrown this out a few days ago after finding it in the back of a drawer so after wracking my brain to think of how to protect the hoses I dug it out from the bottom of the workshop bin!

Today I found some brass scraps to make the drain. I would rather have used something a bit smaller but that slice of brass wasn't going to be used for anything else. You can just about see the bent and stepped ends on the old axle.



I put the big bit in the lathe, cleaned it up, drilled and bored a hole in it. I thought the biggest tap/die I had was 12x26 BSB but then remembered a cheap tap & die set I bought on sale years ago and it had an M16x2 tap and die. If I'd looked more closely and noticed the M16x1.75 pair I'd have used that because I think it would have been an easier thread to cut. I screw cut the screw because I didn't fancy my chances of getting the die to go at all, never mind straight. I couldn't get the die to clean up the thread on the first screw so made it again and cut the thread 0.2mm deeper than "necessary" and that helped, although it was still very difficult to get the die going. The screw cutting itself didn't leave a good thread form even though I was using a 60deg threading insert. The crests still had flats. Maybe the insert can't cut threads this coarse.

Once the thread was cleaned up with the die I put that piece of bar back in the chuck, knurled it, and used it as a mandrel for finishing up the machining on the bigger bit of brass.



Here's the tap and die, and the nasty die holder with a sleeve in it to boot.


Next steps are to drill some tapping sized holes for mounting screws and transfer them to the bottom of the tender tank. I'll use lots of bituminous paint to try and protect the fresh steel revealed by the hole saw, because water will find a way to get trapped I'm sure. That scribed circle is where the bolt holes will go.

[David]

There was more work in the tender than expected but it's back together.

1. New axle.

2. Spacers behind the bearings on the other axle so they don't move about in the axlebox. I know they shouldn't slide about anyway but I can't turn that good a fit.

3. Springs replacing rubber blocks on the front axle (that takes the weight of my feet) to see how that goes. The tender has a pronounced slope with the rubber blocks in which takes the water away from the new drain.

4. Drain fitted. I tried to turn an o-ring groove, and that didn't go well. I filled the resulting water trap with JB-weld.

5. New water hoses with some 'armour' around them to stop them getting holes worn in them.

6. I originally used 10BA screws to hold the axlebox keeps on but these were too fiddly. I'd already replaced them with 6BA on one axle so I changed the other while everything was apart. I also shortened the screws so they were a suitable length rather than having about 8mm sticking out the inside.

7. Replaced the sheared off bolts holding the tank to the chassis. The front one is quite difficult to get in because my hand doesn't quite fit under the coal space, but I figured I must have managed it before so it should be doable!

[David]

I hadn't put this photo on my PC when I wrote the above. The sheared off screw hadn't been put in place yet.

[David]

All went well with the red loco yesterday, In steam for about 3 hours with no trouble.

I'm thinking I need to let it warm up more in the steaming bay. I left with 100psi, quickly lost half of it and couldn't seem to get it back, but after a few laps it started steaming ok.

Both injectors worked all afternoon.

The drain leaks far too much so more bitumen paint is called for. I forgot to pick up my grate and pin yesterday and they weren't there today so someone must have found them and put them away. Luckily I have spares.

Off to a "foreign" track for the first time in years next weekend, so I hope it continues to behave!

[Gary L]

May 9, 2021 4:38:23 GMT David said:

All went well with the red loco yesterday, In steam for about 3 hours with no trouble.

I'm thinking I need to let it warm up more in the steaming bay. I left with 100psi, quickly lost half of it and couldn't seem to get it back, but after a few laps it started steaming ok.
[Snip]

This happens to me too. I don’t think it is a matter of warming up, so much as burning away the low-heat fuel used for lighting the fire; charcoal in my case. Once the firebox is full of proper coal, everything runs better. I try to speed it up a bit by thoroughly raking the fire through before leaving the steaming bay. Sometimes it helps.

HTH

Gary

[David]

The red loco had a somewhat successful trip to foreign metals for the first time in a very long time (10 years, at least).

A cylinder drain refused to completely close, even manually (ie not using the control rods) so not sure what the deal with that is.

I ran it for about 2 and a half hours before I got hungry and bored. I brought it back into steam after lunch but couldn't get it to steam properly on the track so put it away after about 30 minutes.

Through no fault of its own, the two rear roof supports broke from all the bouncing around in the back of the car. It seems it wasn't strapped down tightly enough. I'm only used to driving it about 6 blocks to the local track.

So now I have to take the broken ones off the cab rear sheet and remake them. It never ends - as the topic name says!

After lunch I was sharing a steaming bay road with another loco of the same design (it was a rally for these blowfly locos), also sans roof. I asked him what happened and he said the rear roof supports broke on the way to the rally! He'd also managed to break one of his brand new cylinder drains off, but went out regardless and had a good time.

It was nice to be somewhere where these little locos were the norm and not the 'also rans' among all the scale models.

The drive home this morning was really good. A full breakfast early at a cafe and then a cold, clear morning down a road I'd never driven with no police around and through a bunch of nice hills. With the loco strapped in a lot more tightly.

[dhamblin]

After the various trials and tribulations I'd class that as a success David! Wondering if the sticking drain cock is a bit of something that has lodged in the mechanism - the full size Stanier design types on the LMS were well known for it.

Regards,

Dan

[David]

Yes, it ran well last week and again this week. I would have called it an unqualified success except for the broken roof supports. They're going to take a bit of doing because I'll have to strip and repaint the cab rear sheet because they're riveted to it so I have to take the old ones off and rivet the new ones on.

Luckily the loco isn't a model of anything in particular and I can run it without the cab rear sheet. It's easier to fire that way too.