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Post by runner42 on Feb 9, 2015 7:04:33 GMT
Thanks Shawki and Ian, the stains were easily removed so it maybe soon. Yes I am borrowing Allan's 50mm propane torch that can put out a lot of heat.
The next step is to silver solder the lateral crown stays, that's a question more than a statement. Assuming that this is the appropriate next step do I attempt to silver solder both sides at the same time or one side at a time?
Brian
PS how much should the stay protrude into the firebox? I assume that it should be kept as short as possible to prevent hot spots.
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Post by ejparrott on Feb 9, 2015 9:59:35 GMT
Both sides together.
I usually use a formed rivet head for the stays, so you're looking at something like 1/8" sticking through
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Post by runner42 on Feb 12, 2015 6:57:15 GMT
Thanks Ed,
inserting the lateral crown stays went OK.
Well getting the side stays in place was a challenge and very frustrating, the air in the shed was very blue. The temperature was in the mid thirties so not the best environment for silver soldering, but wait the temperature is going higher in the next week so a little bit of sweat now probably is the lesser of two evils.
Things started OK, to ensure that the side stays were at Ed's suggestion of 1/8" protrusion into the firebox I made with a very small chisel two cuts at an 1/8" from one end so that the when inserted from the firebox side they were held at the 1/8" position and would not fall through. Inserting them was difficult particularly the ones near to the crown. The trial fit was bad enough I have small hands so someone with large hands would need some special tooling. Removing them and fluxing up the areas produce a messy situation, re-inserting the stays put more flux on my hands than on the side stays, but then the fun really started in trying to get the solder rings over each side stay in the firebox. Well after an hour or so I managed it, added more flux and laid the boiler on its side ready for silver soldering. This was completed and I am waiting it to cool down to have a bit of inspection and then into the pickle for the easier task of soldering the side stays to the outer wrapper tomorrow. Then doing the other side.
Pictures to follow.
Brian |
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Post by runner42 on Feb 22, 2015 6:36:29 GMT
I have finished the staying apart from the longitudinal stays that go in after the backhead is silver soldered in. I had to have two goes on a few stays either side and inboard and outboard, that's why the apparent uneconomical use of silver solder is evident. I was more interested in getting a sealed joint than being cosmetically pleasing. I recommend that any beginner provision a 1/3 to a 1/2 more silver solder than they expect to use. At one point I didn't take Julian's advice and pick up the propane gas bottle to feel that it was heavy enough, hence the gas ran out halfway through a heat up, grrrr. Here are the pictures of both sides and the backhead shot showing the penetration of silver solder between the wrappers, which was my nemesis on the crown stays before I developed the technique of heat application. Any boiler maker who cannot apply the silver solder rings between the wrappers as is the case on Doris can achieve penetration by applying the propane flame between the wrappers and pulling the silver solder through the joint from outside applied silver solder.
Brian
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Post by ejparrott on Feb 22, 2015 9:11:48 GMT
Looking good.
I've never bothered with rings myself, and yes I do apply the heat between the wrappers. As I think I've said before, I fit the side stays before the door plate, heat between the wrappers, foundation ring up, and attack the heads with the solder
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Post by Deleted on Feb 22, 2015 10:31:25 GMT
Good morning Brian ,
Can I suggest that you try the boiler back in the frames before doing any more ? Drop it down to the correct height and see if there is any clearance left anywhere .
I only suggest this because the Doris design is notorious for having boilers that don't fit the frames and the boilers end up having to be set much too high and look awful . I hope you have no problem but if you have then some correction is still possible at this stage .
Michael .
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steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
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Post by steam4ian on Feb 22, 2015 12:10:32 GMT
Brian
If there is a problem with fitting the boiler between the frames you can do what Pichi Richi had to do when rebuilding NM25. Over the many years of service the foundation ring had started to bulge out. To get the boiler into the new frames they made a giant G clamp and squeezed the sides of the firebox together.
BTW, good progress.
Regards
Ian
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Post by runner42 on Feb 22, 2015 22:01:05 GMT
Looking good. I've never bothered with rings myself, and yes I do apply the heat between the wrappers. As I think I've said before, I fit the side stays before the door plate, heat between the wrappers, foundation ring up, and attack the heads with the solder Thanks Ed,
you mentioned delay fitting the door plate, which would have made in my case the task a lot easier. But because the door plate is below the outer wrapper fitting the door plate afterwards with say rivets would be near impossible? You must use some other type of fixing in this case?
Brian
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Post by runner42 on Feb 22, 2015 22:20:03 GMT
Thanks Michael and Ian,
yes fitting the boiler between the frames with the altered stay size and spacing to what LBSC specified was always a potential problem, because the lower level stays are going to affect the ability of the boiler to sit below the level of the frames, unless I reduce the protrusion to say 1/8". The between frame measurement is 2 7/8" and the throatplate width is 2 1/4" giving a 5/16" clearance each side so maybe not a problem after all or Michael are you referring to an issue other than the one indicated?
Brian |
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Post by Deleted on Feb 22, 2015 22:31:16 GMT
Brian ,
Several people have reported problems getting boiler to clear various things on engine . Your lower firebox width is actually a bit narrower than expected so that should be ok . Other problem was boiler being too fat on bulged part of firebox and on the larger diameter of boiler barrel and not clearing frames or rear drivers .
You may possibly be lucky and have a recent set of drawings where the problems have been corrected .
Regards ,
MichaelW
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Post by runner42 on Feb 23, 2015 1:40:39 GMT
Michael,
no I don't have a later set of drawings in fact I don't have a set at all. My only source is the free (but not now) pdf files of Doris as described in ME available on the Internet. I have reduced the stays to around 1/8" and the boiler just rest between the frames but with no side movement. I must have been lucky. 
What if any clearance should there be between the boiler and side frames given that things expand when hot.
Brian |
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Post by runner42 on Feb 23, 2015 5:23:05 GMT
(4) I see that you have no allowance for lagging . May I suggest that you consider at least fitting thin metal cover sheeting so as to give better appearance , something clean to paint and something to attach handrails to . michael w An OMG moment. This point went past me when first made but now I understand the relevance. LBSC when designing Doris I assume didn't consider having the boiler lagged because the smokebox diameter is 4.5" and the end of the boiler barrel is also 4.5" so they are flush to each other. Reading the words and music he talks about painting the boiler with a temperature resistant black paint so this enforces my belief that boiler lagging was not on his radar. Bugger.
What makes this doubly worse is that the addition of rod stays in the crown and the stay diameter size at the sides make the need for lagging and cleading on the boiler essential because as is it looks awful. I can see why in the lateral crown stays he used nuts to improve the appearance. If it meant making a larger smokebox tube I would go down that path but the smokebox ring and door would be too small.
What an eleventh hour time to realise this. Anyone have a suggestion as to how I overcome this dilemma?
Brian
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Post by ejparrott on Feb 23, 2015 9:55:18 GMT
Brian I don't use rivets, I make screws from PB102 hex bar. I drill and tap the plates and drill clearance holes in the wrappers. When the time comes to fit the plates, I can fit the screws through the water space, do them up as much as required, then silver solder at the same time as the joints.
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Post by alanstepney on Feb 23, 2015 10:01:15 GMT
LBSC didnt bother with cladding on some of his boilers.
That kept the overall diameter closer to scale, but creates other problems.
No heat insulation and how do you fix handrails?
Simple cladding, and , say, 1/16" insulation, will solve both, but then the OD is wrong and doesnt match the smokebox.
The OD doesnt matter (IMHO) as few people will notice.
The difference from the smokebox does .
A double skin around the smokebox so that the OD is the same as the boiler, is my only suggestion.
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Post by Deleted on Feb 23, 2015 10:11:54 GMT
LBSC didnt bother with cladding on some of his boilers. That kept the overall diameter closer to scale, but creates other problems. No heat insulation and how do you fix handrails? Simple cladding, and , say, 1/16" insulation, will solve both, but then the OD is wrong and doesnt match the smokebox. The OD doesnt matter (IMHO) as few people will notice. The difference from the smokebox does . A double skin around the smokebox so that the OD is the same as the boiler, is my only suggestion. I had the same problem and landed up making a new smokebox!  |
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Post by ejparrott on Feb 23, 2015 10:39:45 GMT
My 2.5" Annie is typical LBSC, no insulation. Handrail stanchions are direct into the boiler and subject to boiler test, in the yellow cert days when she was last certified, that was every other year!
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Post by Deleted on Feb 23, 2015 10:41:19 GMT
Hi Brian ,
Bit of fuzzy logic needed to solve this one .
(1) The Doris design is not a scale replica of an LMS class 5 . Large parts of it are non prototypical . Given that we can add a few non - prototypical features of our own and at the same time make it a better looking engine .
(2) Boiler barrel cleading needs to stand off from boiler barrel by at least enough to get a thin nut behind for the handrail knobs . Since there is a space now we may as well put a bit of lagging in .
There are many examples of steam engines having cleading a bit bigger than smokebox . Sometimes it just happened after repairs but several engine designs had this feature deliberately from new .
(BR 9F had highly visible several inches bigger diameter cleading than smokebox)
There was at least one BR class 5 with this feature . BR class 5 is not exactly the same as LMS class 5 but near enough as regards boiler .
So - suggest use of cleading on barrel just a little over diameter of smokebox , one thin layer of lagging and a nice finishing trim piece at smokebox end . Think it could look very nice and if not pedantically correct it would at least be proper engineering .
(3) Firebox cleading is going to end up oversize come what may so just make a neat job of it . Getting the right shape , visible appearance and nice match to boiler cleading will be more important than getting size exactly right .
(4) There may be a case for making the cab spectacle plate and associated parts a little overscale to match the new boiler shape . In particular the windows in the spectacle plate will be cramped by the oversize firebox cleading and look toy like . Make cab a little wider to get windows right size and shape again .
(5) Just a note about perception . Very few people actually know in detail what a class 5 looks like or how big the engine or individual parts should be . The trick is to create an engine which people ( including yourself) will immediately say - that's a nice class 5 .
Given that the working parts all function ok the rest is just capturing the ' spirit' of the engine .
MichaelW
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Feb 23, 2015 20:54:28 GMT
hi brian,
i would endorse everything michael states. i had exactly the same with an LBSC 'Princess Marina' many years ago. i would certainly advise fitting boiler cleading, and if the cladding underneath is reduced to minimum or nil at the smokebox end it will hardly be noticeable. unfortunately the lack of provision for boiler cladding on LBSC designs is well known, and my apologies for not having pointed this out earlier.
i am very impressed with the progress on the boiler! nearly finished then you can breath a big sigh of relief!
cheers,
julian
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Post by Jim on Feb 23, 2015 21:59:58 GMT
Hi Brian,
Just to add to Julian and Michael's valued comments. Given your location in Adelaide and its hot dry climate you could use an air gap in lieu of lagging where space over the boiler is very tight.
As Michael says the important thing is to capture the spirit of the engine much as an artist does when painting a rail scene.
It's just a thought.
Jim
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steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
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Post by steam4ian on Feb 23, 2015 22:19:03 GMT
Brian.
I endorse the comments made above.
If you look at photos of the SAR 500 class when "streamlined" (except engines 502 and 506) you will see that the cladding was extended over the smoke box so the boiler had a smooth skin. (BTW the 500 class 4-8-2 (later 4-8-4)were the largest non artic locos ever built in Great Britain).
In that you have such good solder penetration with the stays the bit sticking out no longer has a function and can be trimmed off, use a Dremel or similar.
You could streamline the whole engine AT5 style.
Regards
Ian
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