Wooden cleading for stationary steam engine boiler

Hi Folks,

Firstly, I am sorry if you have seen my request elsewhere.

Can anyone give any images and specifications for lagging and cleading stationary boilers. I have a 3 1/2" boiler running a Stuart horizontal and an unidentified vertical engine, but there is a lot of heat being lost from the bare boiler. I am interested in ending up with a timber barrel segment exterior and expect that there will be an insulation layer between the boiler outer and wood.
Your suggestions and images would be appreciated.

Many thanks,
Dave

Try googling "Model Boiler Insulation" - lots of helpful stuff to be found.

Some Kaowool under the wooden planking will give the best insulation.

As for the wood itself although a nice dark hardwood may appeal you really want one of the lighter weight woods which do tend to be a lighter colour though they can be stained to whatever you want to see. Something like Obeche would be good or Tulipwood if you avoid the green bits as these have quite an open cell structure they will help with insulation. As for planking I did describe a way to use the mill and a slitting saw here to give some nice narrow boards, if you don't have that facility then you can by structural veneers or stripwood that would suit. Although this is for a cylinder the same principals apply for a boiler

A few brass band with block soldered to the ends or simply bent to take a brass screw and nut will hold the boards in plac or something like this. It is often easier to handle the cleading if you stick all the boards to a thin fabric (old hankie or bedsheet) they can then be cut to a template and simply wrapped around the boiler.

Few details of one of Ramons boilers being clad here He does more than just Diesels!!

J

EDIT LInk to Ramon's corrected

Edited By JasonB on 25/11/2014 14:32:25

Word of caution...season the wood prior to cutting/fitting as it may shrink rather alot once hot! And I speak from experience..

To season wood: weigh it, place in micro wave oven with a glass of water. Small bit of wood try 15 seconds, reweigh, it should be lighter, repeat until the weight stabilises. A method I used when I was wood turning were I could rough out a bowl in green timber to near to size, season it, then finish the job. If you buy veneer it is already seasoned.

Ian S C

A close look at pictures of full size engines with wooden cylinder lagging shows a half round bead down one edge of each strip. It looks very nice. I don't know how hard this would be to reproduce in miniature, although, many years ago, some one was selling sets of planking moulded in this fashion to fit LBSC's "Lion". ( Titfield Thunderbolt ). Perhaps some one out there knows how to do it?

Maurice."

Maurice, if you have a look at the link I have now corrected to Ramon's build you can see how he ran the beaded moulding. A simple scratch stock would do the same job

Edited By JasonB on 25/11/2014 14:32:49

At model thicknesses insulation won't do a lot so I wouldn't worry about the type of wood and Kaowool which works under metal sheet is going to be a problem under wood as it is compressed. A layer of balsa is easlier.

Your problem might be to find a decent close grained pieec of wood since mahogany that is now grown for building trim is rubbish. An old broken chair might be better - if beech then stain it.

For the beading mentioned look up 'scratch stock' though you can do it with a cutting gauge. A cutting gauge is what joiners use when a carpenter uses a marking gauge. Under a tenner from Aximnster. (eeek this is woodwork- the purists will object so better make your cleading of Swedish iron and paint the planks on).

To save the Kaowool from being squashed it simply needs a couple of hoops wrapped around the boiler to form a space much the same way you need to pack out metal cleading on a traction engine and then its easy enough to fit a layer or two of 1/16" kaowool with a sheet of baking foil between. I laminated the hoops up from some strips of veneer held in place with tape while the glue set, you are then left with "plywood" rings that can be placed where the banding will come and that stops it squashing the wool or distorting the thin metal cleading.

The red hardwood sold for "building trim " is usually Meranti not mahogany and is indeed nasty fluffy stuff, beech does not take a stain well.

.

Maurice,

In another recent thread, I mentioned this:

Many years ago, in Model Engineer, there was an excellent article about building a miniature Spindle Moulder ... for the purposes of model ship-building, I think. [probably late 1940s / 1950s ... small-format mag. with B&W cover]

If someone could find a copy; maybe Neil could re-publish it here.

Vol 111 No 2793, not one I have

.

Thanks, Jason

... at least we now know what we're looking for.

MichaelG.

Sorry Michael, not here, but I can re-publish it HERE.

Neil

(P.S. this is not a regular request service, but as it's a short article...)

I'll make no comment on the "french" cutters that it uses except mind your fingers

.

Brilliant ... Thank you Neil

I promise not to request another [for a while, at least ]

MichaelG.

For a neat result the cleading needs to be tapered in section to fit on the round boiler. I once witnessed a demonstration of cutting wood for a scale Sopwith Tabloid on which the finish ot the wood straight from the small saw table was superb. The saw blade was actually a 3 in metal slitting saw. I had this problem for a boiler about twice the diameter of the Stuart. I fitted a 3 in. narrow slitting saw in the lathe chuck and rigged a table to fit in the 4-way toolpost. I achieved a similar finish and the strips fitted nice and closely together.

If you are making a 'strip planked' canoe, you se the bead and cove.

these boats are made from 1/4*3/4 cedar, generally, and each strip is prepared are with a 1/4 dia bead on one side and matching cove on the other. This lets them be snugged together as they go around the curve of the station moulds. Once on, sand outside smooth.

having built a couple of these, I reckon the tooling design is poor and the beads need to be more like 5/16 or 3/8 diameter as matching the wood thickness and diameter means you run into problems on tight curves.

would not be hard to do this for cleading- I am about to do one and hadn't thought of this. Was going to do a coopered approach (wedge shaped cross section) which is less tolerant of error.

again, based on canoe experience, the cove is harder to get right than the bead. If you were to apply the cove before cutting the strip it might be under better control. At this scale, scraper will be more than adequate if you watch grain direction. Look for a piece of timber with a slight consistent grain run out along the edge, rather than one too perfect- counter intuitive, but you will get a better result more easily and strength is not an issue here.

i have to confess that I do still do a fair bit of woodwork in spare time, it is not as scary as some think!

An uncle of mine built three 16' run a bouts(boats) using the bead and cove method, and fiber glass over the top. He was 84 at the time, and had been an amputee from the age of 21 (motor bike accident).

Ian S C

Ian,

it was good fun, built the first one 'just because', then got carried away and did a 23'double kayak to paddle the Murray marathon with my wife. That was 400km in 5days- a clear case of enthusiasm winning over common sense.

the kayak hangs over part of the shed and routinely clocks my 6'4" son on the head