Overcoat for Boiler !

[GWR 101]

Hi all, a bit of advice please. I am presently painting the boiler cleading which I hope to fit shortly. I am sure I have seen some where that in addition to the cladding it is also advantageous to fit a layer of aluminium foil. So the question is if this is correct does it go between the boiler and the cladding or between the cladding and the cleading. I assume its shiny side innermost, and if its next to the boiler is there any danger of a chemical reaction. Many thanks for any advice, regards Paul.

[robmort]

Anything with a shiny surface will help reflect, and not radiate, heat. That includes the boiler surface itself, if it can be kept shiny e.g. with a layer of clear lacquer.
Ideally put aluminium foil between layers of insulation, so it does not touch the metal on each side, but any other way will help.

Rob

[GWR 101]

Hi Rob and thanks, so is that a layer next to the boiler and also a further layer on top of the insulation matting both with shiny side innermost. Regards Paul

[smallbrother]

Apr 24, 2016 9:06:34 GMT GWR 101 said:

Hi all, a bit of advice please. I am presently painting the boiler cleading which I hope to fit shortly. I am sure I have seen some where that in addition to the cladding it is also advantageous to fit a layer of aluminium foil. So the question is if this is correct does it go between the boiler and the cladding or between the cladding and the cleading. I assume its shiny side innermost, and if its next to the boiler is there any danger of a chemical reaction. Many thanks for any advice, regards Paul.

Hi Paul,

Showing my ignorance but what is cladding and what is cleading?

Pete.

[robmort]

Apr 24, 2016 14:49:57 GMT GWR 101 said:

Hi Rob and thanks, so is that a layer next to the boiler and also a further layer on top of the insulation matting both with shiny side innermost. Regards Paul

The more the merrier!
The more layers in the sandwich you can do the better the insulation. You can buy multilayer thin insulation for roofs but it's not cheap.
Doesn't matter which side is inside or out.

[ettingtonliam]

Apr 24, 2016 15:42:31 GMT smallbrother said:

Apr 24, 2016 9:06:34 GMT GWR 101 said:

Hi all, a bit of advice please. I am presently painting the boiler cleading which I hope to fit shortly. I am sure I have seen some where that in addition to the cladding it is also advantageous to fit a layer of aluminium foil. So the question is if this is correct does it go between the boiler and the cladding or between the cladding and the cleading. I assume its shiny side innermost, and if its next to the boiler is there any danger of a chemical reaction. Many thanks for any advice, regards Paul.

Hi Paul,

Showing my ignorance but what is cladding and what is cleading?

Pete.

I think in this thread, cladding = lagging and cleading = the thin metal sheeting over the lagging. Could be wrong about this, it has been known.

[smallbrother]

From a Google search it seems cleading is the term for a covering that is designed to retain heat. In the steam engine context this would be insulation. Cladding is the external cover. This would be the outer, painted sheet of metal wrapped around the boiler's exterior and covering the cleading.

Unfortunately this seems opposite to the replies kindly sent above.

The mystery deepens!

Pete.

[GWR 101]

Hi, many thanks for all the contributions which seem to have opened a debate about terminology. I believe it was on this site that I was informed of the appropriate use of the two terms, as I understand it the outer most layer which can be of various materials even wood is referred to as the cleading. I believe this word has Scottish origins so perhaps someone from the northern parts may wish to elaborate. .

I am still not sure if the addition of tin foil is considered worth the effort and would be interested in the views of anyone who has adopted this method. Regards Paul

[GWR 101]

Hi Steve, many thanks for that. I will omit it from the layers I intend to use, however I can't agree with your bin suggestion as I believe the best place is round the Sunday joint.  Regards Paul

[steamcoal]

I have recently completed the boiler insulation for my Maisie re-build and offer here my effort for you to see.

The insulation is a thick woven marine fibreglass mat (not chop strand) and the outer is aluminium tape which will help reflect the heat back towards the boiler. Not that Maisie was ever short of steam!

Took a few hours to complete one evening.As the boiler had no thermal insulation I did not want to make the covering too thick so as might effect the circumference of the cladding (If thats the correct terminology?)

Anyway its done.

[smallbrother]

When I stripped my Polly down the original insulation (cleading/cladding!?!?!?) was very sparse. I replaced it with stuff from Pollymodelengineering.

I can't say she steams any better, at least nothing I can detect.

Pete.

[GWR 101]

Hi Steamcoal, thanks for your comments. I must admit I had not thought of using tape, it seems like a good idea and even if it doesn't make a significant difference it will help keep the insulation in place whilst I fit the outer wrapper. Regards Paul

Hi Pete, I have used some insulation from one of the usual suppliers intended for use on miniature boilers. I believe its about 1mm. thick so with the outer wrapper and boiler bands it matches nicely with the smoke box. Regards Paul

[smallbrother]

Whilst digesting lunch and resting my feet ready for dog walk number 2 I have looked up terminology in "The Model Steam Locomotive" by Martin Evans.

He refers to lagging (on the inside) and cleading (on the outside). Therefore, from now on, I will use that terminology.

Pete.

[GWR 101]

Hi Pete, thanks for that I was beginning to wonder if I had dreamt it all up.   Regards Paul

[jma1009]

I can confirm the outer metal layer is cleading, and the insulation between cleading and boiler is cladding.

In miniature the main point of cladding is to protect the paint on the cladding from the effects of heat. The general heat loss is insignificant externally on a miniature loco boiler from an efficiency point of view, but the paint will get discoloured over time on the cleading if it is not insulated with cladding.

Obviously this rather depends on what paint you use and it's colour, and also whether you have boiler bands fully lined out that might be affected.

I still have a roll of thin asbestos backed with foil. I can see no disadvantage in adding foil. I have never done it myself as apart from using the above asbestos foil backed stuff I have used for very many years the stuff used by Hayden and illustrated in his excellent pics.

I have often thought there ought to be a debate here on cladding for miniature locos, with a view on 'modern' available materials, plus the sort of excellent analysis Steve has added above.

Cheers,
Julian

[GWR 101]

Julian many thanks for your thoughts, I have used some material from one of the usual suppliers for the cladding and as previously stated will probably hold it in place with some tape as mentioned by steamcoal. The outer wrapper (cleading) in my build is brass sheet which I have etch primed and top coated in 1900ish GWR Green, well that's what it says on the tin, I have given it several coats but not sure how true the colour is as I am sure the primer colour has an effect.

Regarding the bands as it's not a prototypical build but based roughly on GWR 101 I intend to just leave the bands self colour (brass). Which raises the question if it would be a good idea to give them a coat of clear varnish to prevent tarnishing. Regards Paul

[Cro]

Just to throw a curve ball in.....working off BR drawings the insulation is classed as the Mattress and the outer coverings are the Clothing for both boiler and backhead..... I have always classed it as lagging (I have used cork on the 9f) and cladding (brassand copper sheet) - think about a house you CLAD the outside of it so it seems sensible to me for the boiler to be clad in metal. 

Adam

[GWR 101]

Hi Adam, yes as I mentioned the word cleading appears to be of Scottish origin from the word for clothing, I did suggest some one from north of the border may be able to confirm this, but no response yet. Regards Paul

[miketaylor]

I have a feeling that the use of the cleading word is actually related to the older boiler "clothing" made from wooden strips. Not sure why, but am fairly certain there is a connection at the back of my aging brain.

Mike

[GWR 101]

Hi Mike thanks yes that seems logical, sorry for the delay but abroad at the moment and so having to use public networks. Regards Paul