Smoke Box Build

[GWR 101]

Hi would be glad for a little help, please don't laugh but i have been building a Juliet 2 in 3 1/2 gauge since 1965 !. I have now nearly finished the motion gear and have started on the smoke box, its a made up one from parts sourced from A.J.Reeves, my question is :- I want to have a riveted appearance at each end, is it best to put rivets through the outer tube then clean up the inside or fit the smoke box door ring which slides inside the tube and then rivet them together. the O.D on the ring is  0.375 long so assuming I leave it projecting the tube by about 0.062 I could set the rivets back from the front by about 0.187. The drawings don't go into any detail, neither does LBSC's Shop, shed and Road or M.Evans Manual of Model Steam Loco Const. Any suggestions would be gratefully received as after this length of time I want it to work and look right. Thanks Paul

[jma1009]

hi paul,
its a freelance design so it matters not one jot whether there are roundhead rivets on the smokebox or not. they are a pain to paint.
fit dummy rivet heads if you want into the smokebox tube. they can be loctited in place. personally i wouldnt bother and the extra pointless work is only going to delay you finishing the loco still further! some fullsize locos and builders fitted smokeboxes together with roundhead rivets others were countersunk. unless you are modelling a particular loco that had them in fullsize then i would never add them.
cheers,
julian

[GWR 101]

many thanks, I will leave out the rivet approach and just braze the ring into the tube, I can always add some cosmetic rivets at a later date.

Regards

Paul

[ejparrott]

A friend of mine is building a 9F in 5". He's decided to go the route of building the basic engine and getting it running, and then adding the detail parts at a later date, when he's had a play with it, an knows its running well. It does mean that it gets in steam quicker.

[GWR 101]

Many thanks. Yes I think that's sound advice, I know it's fatal to set deadlines as I have been making it for about 47 years ! However as I have only the eccentric and valve rods to complete the motion parts, then the steam and exhaust tees and pipes then I hope to try it on compressed air by the start of the New Year. If all is well and that's a big IF I am considering getting the boiler made by someone else whilst I get the rest completed. Paul

[jma1009]

hi paul,
its a very easy boiler and shouldnt take more than a few weeks of spare time so why not build it yourself. if you need any help let me know. ive built 5"g boilers in 6 weeks of spare time. a late friend of mine would build a boiler in a week during his leave.
cheers,
julian

[Shawki Shlemon]

Details lift the appearance of the engine , I envy the builders who fit a lot of details and accurately but alas I personally can't do it to those extends , it is a matter of patience and commitment , I have the second but not the first , so, as long as the builder is happy with what he / she is building the details are sufficient , whatever level they are at .

[GWR 101]

Hi both many thanks for your help and positive advice sorry for the delay but have been making the eccentric rods which are now finished and the trigger for the reversing lever handle, it seems to take for ever to make what is something so small. Regarding the boiler and any added details I think I will get the mechanical side working on air then braze the smoke box and see how that goes. Dependent upon the outcome, last time I did any soldering on the central heating pipework it leaked !!, I will then make a decision on how to proceed. Once again many thanks Paul

[GWR 101]

Hi sorry to resurrect this again but I noticed in another thread that mention was made of making the ring just a press fit into the tube, so enabling removal for ease of access. If this is an acceptable method, is it "pinned" there someway?. Following that and fixing the various bits to secure the door I am then contemplating Silver soldering the smoke box to the saddle. Any thoughts / suggestions gratefully received. Paul

[Deleted]

Mar 24, 2014 13:41:25 GMT GWR 101 said:

Hi sorry to resurrect this again but I noticed in another thread that mention was made of making the ring just a press fit into the tube, so enabling removal for ease of access. If this is an acceptable method, is it "pinned" there someway?. Following that and fixing the various bits to secure the door I am then contemplating Silver soldering the smoke box to the saddle. Any thoughts / suggestions gratefully received. Paul

hi Paul

I can only give the advice for what I have learnt to date...Regarding the ring I can fully understand why this is a good idea, I can't get my hands into the smoke box on 4470 which I suspect is a fair deal bigger than yours so yes make it removable if you can. I have to get my son's to do any work inside of the smoke box, my way around this for the future is simple.... not to make any loco's that I can't get my hands in...
Personally I wouldn't permanently fix the smoke box it it's saddle as if you get it only slightly wrong in alignment you'll have great difficulty fitting the boiler and sealing the joint between the two..
Other's may disagree but I wouldn't do it or at least certainly not at this stage until the boiler and associated parts have been fixed to the frames to check all aligns correctly..

Regards

Pete

[GWR 101]

Pete thanks that sounds like good advice on both counts. My next job is to fit some hinges, handles etc. to the door which I can then fit to the ring. I was going to follow "standard practice" and make the cross bar removable, but even this does not leave a lot of room. I think my biggest problem is that I am just finding things to do to avoid starting on the boiler. Paul

[70043]

Hi Paul,
           My advice is plan for the worst - think about future maintenance and how to make it as hassle free as possible.
On my 7.25 Brit I have fitted the ring with discreet counter-sunk screws, sealant ensures an air tight joint and cosmetic rivets make sure it looks the part. Again the smokebox is attached to the saddle by hex screws.
I am currently recommissioning a 5"gauge loco that I didn't build. This loco has it's smokebox ring soldered in and the superheater (that is leaking) won't fit through it - I wish he'd screwed his in!!

Andy 

[GWR 101]

Andy many thanks, yes it does look like trying to get a quart into a pint pot. I notice M. Evans suggests making the smoke box in two halves but I just can't convince myself that doesn't cause more problems than it solves, so I have no plans to go that way. Paul

[fostergp6nhp]

IIRC the smokebox on the Don Young Mountaineer is horizontally split for ease of access as even tho its a largish scale it is of a small prototype so 12"/1ft hands wont fit in.

[ejparrott]

I've suggested to David that he build his 9F smokebox split, and I'll do the same if I ever build a 'mainline' engine. My Manning Wardle smokebox will be all riveted and the superheater designed to fit thrlough the hole!

[GWR 101]

Hi, have been away for a couple of weeks and to avoid withdrawal symptoms I started thinking again about the fitting of the smokebox ring (fatal) and had a thought. I wondered if I constructed in brass from 1/16" thick by about 1/4 wide plate rolled into a tubular ring a good fit inside the front of the smokebox I could rivet this in place with this ring set back from the front by the amount the door ring goes in. This would then give a fixed shoulder to seat against, increase locally the rigidty of the smokebox and hopefully assist in the sealing. Additionally it could possibly provide an anchor place for some means of retaining the door ring along the lines of a couple of screws from the door ring to nuts brazed to this ring. Has anyone any experience of this approach or am I just over engineering a solution. Paul

[Geoff]

Apr 16, 2014 13:38:19 GMT GWR 101 said:

Hi, have been away for a couple of weeks and to avoid withdrawal symptoms I started thinking again about the fitting of the smokebox ring (fatal) and had a thought. I wondered if I constructed in brass from 1/16" thick by about 1/4 wide plate rolled into a tubular ring a good fit inside the front of the smokebox I could rivet this in place with this ring set back from the front by the amount the door ring goes in. This would then give a fixed shoulder to seat against, increase locally the rigidty of the smokebox and hopefully assist in the sealing. Additionally it could possibly provide an anchor place for some means of retaining the door ring along the lines of a couple of screws from the door ring to nuts brazed to this ring. Has anyone any experience of this approach or am I just over engineering a solution. Paul

Hi Paul,

The SAR Class 2C that my father built has a press fit smokebox ring. This is held in position by a single 8BA bolt that is almost invisible. Because of the width of the smokebox ring, it needs to be removable. You shouldn't need that inside ring you mentioned unless the fit is quite loose. Sometimes simple is best.

Cheers
Geoff

[GWR 101]

Hi Geoff,

Thanks for coming back on this, I have moved along a bit and have now finished the smoke box door fitting. I made a removable bar for the dart to locate in and having riveted two hinges to the door I then used the door locking gear to hold the door in place whilst I fitted the hinge brackets in place on the ring. I now have what I consider a perfectly good airtight seal of the door, hopefully unless I cause some serious distortion this will stay the case. Looking at the opening it certainly looks extremely small so I am proposing to make the entire ring assembly removable, and as the ring is an extremely good fit in the tube I have decided to as you suggest and not make an inside ring.

What I am proposing to do (and I am sure that this has been tried before hopefully with some success) is to secure the ring into tube with some 10BA screws around the outside where the rivets would be on some full size loco's. To do this I have ordered some round head brass screws with no slots so hopefully this will not look too out of place. Well that's the plan, I will see how it goes. Paul

[uuu]

The push-fit ones I've come accross have been satisfactory without screws, needing a firmish tug to pull them off, allowing the door to be used for most purposes. But I have seen round head screws used elsewhere, within a row of rivets, and they merged in quite well. So it sounds like a good plan.

Wilf

[GWR 101]

Thanks Wilf, I am awaiting delivery of the screws so will hold fire until they arrive to decide how many I use spaced round the circumference. I have ordered brass nuts as I think that might make it easier to use the screws without the slots rather than tapped holes. I might braze a small pip under the screw head and have a location slot in the hole to prevent the screws turning, I will decide on this when I get round to assembly. Thanks Paul