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Post by Roger on Nov 4, 2021 11:43:24 GMT
I've not spent much time on the loco in recent weeks, but problems continue with the water gauge which just doesn't reflect what is going on in the boiler. After stripping it down as far as possible, we've poked through the passageways and can put wire straight through into the boiler space, so both passageways are confirmed open, but the water doesn't seem to behave as it should. Next step is to get a bit more drastic and gently heat the backhead with a view to removing the solder around the water gauge fittings, take the fittings out and see what this reveals. We are also toying with the idea of modifying things to fit a turret, allowing for a much taller water gauge and the pressure gauge and blower take-offs to come from there instead. This hasn't been fleshed out in any detail, we'll try the above step first! Can you see how much of the fitting protrudes inside the boiler? It may be that it goes in too far. I understand this can cause problems.
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Post by andrewtoplis on Nov 4, 2021 12:25:06 GMT
Hi Roger Thanks for the reply, I think we'll have to get the fittings off to see this, unless you can think of a way to measure it in situ? I guess we could try one of those tiny cameras with the safety valve removed?
I could see this being a problem with the bottom fitting, where the fitting is below the crown sheet (the actual gauge glass is in the right place) which would give a very limited water space between inner firebox and fitting if it was too long. I believe the top fitting goes straight into the steam space though.
Andy
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nonort
Part of the e-furniture
If all the worlds a Stage someone's nicked the Horses
Posts: 277
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Post by nonort on Nov 4, 2021 15:23:48 GMT
It sounds to me that you maybe experiencing the beginnings of priming due to a contaminated boiler. I would suggest a good wash out with washing soda to get rid of any oily surfaces. The gauge glass could also do with a good scrub up with a pipe cleaner and the same solution. The slightest contamination will show itself as the boiler pressure rises. Best of luck.
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Post by Roger on Nov 4, 2021 23:36:24 GMT
Hi Roger Thanks for the reply, I think we'll have to get the fittings off to see this, unless you can think of a way to measure it in situ? I guess we could try one of those tiny cameras with the safety valve removed? I could see this being a problem with the bottom fitting, where the fitting is below the crown sheet (the actual gauge glass is in the right place) which would give a very limited water space between inner firebox and fitting if it was too long. I believe the top fitting goes straight into the steam space though. Andy You probably will have to take the fittings off to see what you've got. I do have a small camera, but whether you'd be able to get it where you need is another matter. If the fittings are too long, they'll have to come off anyway, so I think I'd go straight for that.
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Post by andrewtoplis on Nov 5, 2021 21:06:13 GMT
I've had a busy week but the water gauge problem is nagging at me. Earlier I thought of a test so stupidly simple I should have thought of it before.
I removed gauge glass entirely, leaving the fittings open to the air. I then filled the boiler slowly until water came out...of the top fitting only!
As I can run a wire through the bottom fitting, and it clearly goes through the fitting and into the space beyond, I can only assume that the fitting is either too long and goes right the way to the inner firebox or is somehow too caked in scale which stops water getting through (or both).
In order to remove scale, I have some citric acid granules in the cellar, would anyone advise filling the boiler with a very weak dilution and leaving it for an amount of time? If so how strong and how long?
Thanks in advance.
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Post by andrewtoplis on Nov 5, 2021 21:08:11 GMT
I do have a small camera, but whether you'd be able to get it where you need is another matter. Thanks Roger, I agree it would have to be a very tight bend just inside the boiler and then getting sufficient focus on an object less than an inch away, so perhaps this rules it out
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Post by Roger on Nov 5, 2021 22:34:45 GMT
Why not just unscrew the bottom fitting since the glass is out now? Then you can see how long it is, and clear it out from the back.
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jma1009
Elder Statesman
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Post by jma1009 on Nov 5, 2021 22:34:56 GMT
Hi Andrew,
Strip the plastic off a tie for freezer bags etc to get the very thin wire. Bend the end over very slightly. You can then via the water gauge blowdown measure the distance to the outside of the inner firebox door plate, and how far the lower gauge glass fitting protrudes into the water space.
I don't know the Canterbury Lamb, but you ought to have a gap of 3/16" minimum for the above.
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Post by andrewtoplis on Nov 9, 2021 19:22:31 GMT
Why not just unscrew the bottom fitting since the glass is out now? Then you can see how long it is, and clear it out from the back. It is soldered on Roger! In hindsight I should have seen this a mile off and perhaps left the loco alone, but we beginners live and learn
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Post by andrewtoplis on Nov 9, 2021 19:31:55 GMT
Hi Andrew, Strip the plastic off a tie for freezer bags etc to get the very thin wire. Bend the end over very slightly. You can then via the water gauge blowdown measure the distance to the outside of the inner firebox door plate, and how far the lower gauge glass fitting protrudes into the water space. I don't know the Canterbury Lamb, but you ought to have a gap of 3/16" minimum for the above. Hi Julian Thanks for the tip, I tried this last evening. Unfortunately the end of the wire doesn't seem to 'drop' into the gap (if you see what I mean) which is consistent with the fitting going all the way to the inner firebox itself. I'll try again tonight...
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Post by chris vine on Nov 9, 2021 21:03:08 GMT
can you blow through the hole where the blowdown valve goes in. That might give you a clue as to what is going on.
My only useful question is maybe is there some scale blocking it? perhaps I missed this earlier.
If it is soft soldered in, you could probably ease it out with a little heat from a very small gas torch on the fitting, and something on it to feel when it just starts to move...
Chris.
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Post by andrewtoplis on Nov 9, 2021 21:25:22 GMT
Thanks Chris, I'm afraid there is no blowdown valve on this engine!
We'll try and get it out at the club tomorrow night and I'll report back here
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Post by andrewtoplis on Nov 11, 2021 12:05:18 GMT
Well, here is the answer...it was caked solid! There is actually very little water space in behind the firebox at the best of times - we've cleaned out the hole, tested the water flows out happily and refitted the existing fitting with a new copper washer - surprisingly there was the mortal remains of a fibre one in under all that solder! The gauge now works! Now to leave a little acid in it for two days, then steam test next week
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 11, 2021 12:29:56 GMT
Good news. It's always nice when you can actually find the reason for a problem.
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Post by andrewtoplis on Nov 18, 2021 12:45:47 GMT
Steam test results from last evening, sorry these are only very brief and wobbly clips.
First one, steaming happily before the blower blocked itself up!
Second one shows the loco with a fresh fire and propped up at both ends doing the job as the designer intended!
Still some work to do, the regulator is leaking badly as are various joints which will be given new gaskets next week! I must say the fire doesn't last very long and the pressure seems to go from everything to nothing in a very short time. I'm yet to see how long this will last on the track (or how long I can keep up with it!).
EDIT - I just cannot get the videos to embed from flickr, sorry all! Suffice to say it steam nicely but has some leaks ...
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uuu
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Post by uuu on Nov 18, 2021 13:08:02 GMT
Here they are: , on Flickr , on Flickr Not sure why I can get them to go where you can't. Wilf
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Post by andrewtoplis on Nov 18, 2021 13:21:18 GMT
Thanks Wilf - I couldn't get the embed bit to work for some reason!
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timb
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Post by timb on Nov 18, 2021 13:45:45 GMT
Excellent Andrew, well done!!
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Post by andrewtoplis on Nov 27, 2021 16:07:32 GMT
Keeping going with my updates here,
Just incase I didn't mention it before, the loco has fallen over at some point in the past, bending the steam pipe assembly which is such a feature of this design. Once this had been removed it revealed quite how badly out of shape these are, which may account for why the joints leaked so badly!
So, rather than just replace the gaskets I am going to remake the whole pipes (using a slightly larger diameter pipe), the regulator itself seems ok and will be reused. This should also sort the stiff regulator as the bent pipes meant the linkage isn't straight.
More to come next week, progress is slow but steady. The lubricator is the next challenge as, at present, it feeds into the steam pipes on the wrong side of the regulator...
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Post by David on Nov 30, 2021 6:49:38 GMT
This sounds a little similar to the problem I've had forever with my boiler. I battled for years with blocked injectors and it wasn't until I saw a big piece of crud on the boiler side of the blower valve when I took the plumbing apart the penny dropped that the problems were coming from inside the boiler and not the tender.
I gave it a dose of almost boiling citric acid, left in overnight.
This had the unintended consequence of dissolving crud from the regulator and it started running out the cylinder drains. That didn't seem to have any lasting effect luckily.
I don't suffer from so many runs stopped due to blocked injectors though.
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