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Post by manofkent on Jan 10, 2022 18:26:43 GMT
I am about to add lagging to my Bantam Cock loco.
I have some 8" wide brass sheets to put around the boiler, with brass banding.
Sorry for the daft question, but do I overlap the sheets as they sit along the boiler, or just butt then together with the banding?
Is there a best practice way?
Also would you bother to cover the throat plate, which I anticipate might get tricky to cover.
Many thanks as ever
Joh
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mbrown
Elder Statesman
Posts: 1,713
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Post by mbrown on Jan 10, 2022 20:34:17 GMT
I think it would be usual on a model - and to the best of my knowledge in full size practice as well - to overlap the cleading sheets where they meet if the join is along the length of the boiler. This means that you can tighten the sheets down onto the lagging as you tighten the boiler bands and any surplus sheet just goes into the overlap. As the thickness of the lagging can vary, the overlap also allows for this as the overall diameter can adjust slightly to suit without leaving a yawning gap.
In full size practice, the cleading sheets often covered half the boiler diameter and were slightly overlapped at top and bottom. In our sizes, with over-scale material thicknesses, it can be hard to make that look neat, but it is often true to prototype.
If you are talking about joints around the circumference of the boiler, it is usual - again in full size as well as models - to butt the joints up against each other and cover them with a boiler band. That way they remain the same diameter. In that direction, the dimensions aren't affected if the lagging thickness varies.
As for the throatplate, it is worth lagging if you can. My recollection of Bantam Cock is that the throatplate butts up against the frame stretcher and won't leave much room, but I may have misremembered. Basically, the more heat you can keep in, the better!
Hope that helps.
Malcolm
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Jan 10, 2022 21:02:22 GMT
Hi, my own method is to make the sheeting (some call it clothing, cleading, or cladding) for the barrel section from one piece, but this is just for ease! Obviously the real things are made from several pieces and the curved edges would normally be butted together under a boiler band, as you say. But the joins and bands would be arranged to occur over a supporting crinoline to keep everything neat and in line etc. There is no reason why your proposal of butting sheets together wouldn’t work....preferably supporting the joins somehow. I’m sure it’s possible to create the look of the real thing with lap joints as well, but the “steps” might look a bit too obvious? It is entirely up to you regarding this sort of thing. Clothing the throatplate can seem daunting, but thin brass, or copper for instance, can be formed into the required shape without much difficulty, if annealed as required. You could make a wooden former and form it round that, adjusting here & there until it fits properly to the firebox side / barrel clothing. This is what my 9F boiler looks like “naked”, the crinolines are 1/4” x 1/16” brass strip with little “standoffs” soldered on the circular ones, to space them away from the barrel itself:- Cheers Don
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miken
Part of the e-furniture
Posts: 471
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Post by miken on Jan 10, 2022 22:34:35 GMT
I always add a bit of soft solder to the joint, then if you want to remove the boiler bands for painting, it stops everything from twanging apart and moving.
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Post by andyhigham on Jan 11, 2022 16:35:54 GMT
The "Caribou" I bought has the cladding made from tinplate. Paint seems to stick to it rather better than to brass
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on Jan 12, 2022 0:22:52 GMT
The "Caribou" I bought has the cladding made from tinplate. Paint seems to stick to it rather better than to brass I used tinplate for Paddington's cleading too. It is springy and less easily dinted than brass, so it can be used in relatively thin sheets, which in turn means that the problem of visible overlaps is not quite so obtrusive.It isn't very easy to source (the usual suspects don't stock it) but I eventually found a supplier on the internet. Back in LBSCs day, they used to cut the tinplate they needed from old oil drums! Gary
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weary
Part of the e-furniture
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Post by weary on Jan 12, 2022 8:53:23 GMT
A 'handy' source of tinplate can be restaurants, take-aways, etc. Their cooking-oil is often delivered in nice large tins about 18 inches tall and 15 inches diameter some of which become 'rubbish' once the oil has been used.
Regards, Phil
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Post by manofkent on Jan 12, 2022 22:01:42 GMT
Thanks all for your replies. I am using 15 thou thick brass sheet for the lagging. Just started today, bored the two holes for the safety valves between two blocks of wood, and looking at how to fashion the lagging over the firebox.
I get that the lagging is secured around the boiler with the bands, but how is it held in place on the firebox sides?
I was planning to simply stick the fibre lagging material to the insides of the brass lagging sheet, but Don's helpful picture of spacing/banding inside the lagging has made me wonder if I a missing a trick here?
Any comments gratefully received.
I will try and post a picture in the next few days.
John
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on Jan 12, 2022 22:56:22 GMT
Thanks all for your replies. I am using 15 thou thick brass sheet for the lagging. Just started today, bored the two holes for the safety valves between two blocks of wood, and looking at how to fashion the lagging over the firebox. I get that the lagging is secured around the boiler with the bands, but how is it held in place on the firebox sides? I was planning to simply stick the fibre lagging material to the insides of the brass lagging sheet, but Don's helpful picture of spacing/banding inside the lagging has made me wonder if I a missing a trick here? Any comments gratefully received. I will try and post a picture in the next few days. John It's usually a variation on a screw into a bush soft-soldered onto the firebox side, which forms an anchorage for half a band each side. The GWR at least would have the two half-bands connected by a screw tightener on top of the firebox. The anchorage bushes need to be positioned somewhere in the reverse curve of the firebox, a little bit higher than the top of the frames. Other railways might differ in detail, but probably not by much. Gary
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Post by philh1aa on Jan 14, 2022 11:36:20 GMT
Another approach.... According to the description, the very similar sized LBSC 'Betty' didn't have any lagging or cladding around the boiler barrel. The boiler bands were simply wrapped around the copper boiler shell. The firebox side stays were covered with a thin sheet.
LBSC had some strange methods (looking back now from 2022) but he might have had a point. Does the very thin lagging really make much difference anyway? I would agree that a sheet is better for fixing the hand rails rather than drilling and tapping the boiler shell though.
Phil H
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Post by suctionhose on Jan 14, 2022 12:01:09 GMT
While probably not especially helpful to the OP, it is related to topic. On my 5"g models I have aimed to make the cladding sheets in as few pieces as possible ie one piece if I can get away with it. Some, eg. Belpaire boilers require a front and back piece to support the firebox cladding. If the throatplate is visible, it's nice to cover it. These pics are from my 3" traction engine which has 7 sheets cut and rolled from 0.75 stainless sheet to fit around umpteen protuberances. There is only an air gap under - no insulation media - and I came up with a new concept (for me) of rolling a corrugated strip to align and space the cladding sheets. Worked out very well in practice.
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Post by philh1aa on Jan 14, 2022 16:55:04 GMT
Ross,
Really interesting method. Did you corrugate the St/st rings yourself before bending them round your boiler or do you buy the sheet or strip in that form?
Phil H
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Post by suctionhose on Jan 14, 2022 19:51:33 GMT
Hi Phil, I corrugated the strips by feeding them through a pair of gears mounted on a block of wood. Wood because it took a few goes to get the centres such that the corrugations were the desired height. An adjustable device would have been better but life is too short to make fancy tools that never get used again!
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Post by andyhigham on Jan 14, 2022 20:01:28 GMT
I have often thought that the full size practice of using wooden slats for insulation would be a good move. Unlike fibre insulation it cannot get soaked with water.
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Post by andyhigham on Jan 14, 2022 20:20:01 GMT
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Post by manofkent on Jan 14, 2022 22:01:41 GMT
So I have cut the brass sheets and tried them on for size. The firebox sheet is 15 thou brass which is a bit hard to bend smoothly round the boiler. The other two sheets are 10 thou brass which is much easier to fit. Phil H. The boiler came off the loco for some repairs. One repair is on the outside, and would look pretty ugly if I just painted it over. In any event I wanted to try painting it as if in its last years - BR post 1954 green. I think the engine will look very good in this darker green. Also we run throughout the year at my club - Tiverton Model Engineers, and our track is in a field high up on the edge of Exmoor. It can get pretty cold for driver and engine sometimes! So I thought some lagging would definitely help. I am attempting a picture of it fixed temporarily. I will probably redo the firebox end in the thinner brass before final fixing. John IMG_20220114_153519 by John Hilton, on Flickr
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