Steam pipe insulation

I need to create an insulated and painted steam line between a vertical boiler and a rotative beam engine which is to be entered into a local competition. My use of plaster of Paris bandage has produced a thermally satisfactory result but a horrible lumpy and pitted looking pipe covering. I am thinking that a smooth plaster using children's casting plater would be usable and the simply paint using the same paint used on the metal work. But will that stand up to the heat and expansion when running with steam?

What is the exhibition technique?

Quite a good result shown here and how it was done a couple of posts later.

If using a powdered pollyfilla I would add upto 20% PVA wood glue to the water as it makes it a lot more workable.

Edited By JasonB on 21/07/2016 11:16:15

I think I just used string and white paint for this.

I think a lot of it will come down to the scale of the model. String and tape would not look out of place on a small workshop engine or on a small launch which would typically be plumbed up with screw fittings say upto 2" BSP.

Once you start getting upto larger engines found in a factory, pumping station ot large ship which would more likely have the pipework and fittings joined with flanged connections the string/tape looks out of place and heh smoother insulation more in keeping.

Just had a look at James Lauders medal winning Leake compound and he used a similar method to the one in my previously posted link

Edited By JasonB on 21/07/2016 13:25:21

On my steamboat, I used white cotton string from £land and 'painted' it with several coats of white correction fluid - seems fine so far!

Depends on diameter of pipe you're using but for best appearance buy some white,woven sports shoe laces. Cut off the end bits and 'thread' the lace over the length of pipe. Get some fine brass wire (empty bottle of Rioja !) and wind that around the ends of the lace to bind it to the tube.

The "shoe lace lagging" can now be painted with a water/Polyfilla mixture and as Jason sugggests, add some PVA glue. If you don't make the Polyfilla mix too thick, the effect looks quite authentic.

Once you've chosen your string (assuming you go down this route) I do the following. Superglue the first couple of windings then apply a light coating of UHU type glue along the next six inches, wind on the string and continue in this fashion until you reach the desired end point. Don't cut the string yet! Hold the pipe down somehow and attach the loose end of the string to something so as to keep the whole lot in slight tension. Apply superglue to end windings and then cut off surplus loose string. I find that different paint types give very different visual appearances (stating the obvious!) but apply plenty as it helps bond the string together.

I have just been given by my wife some stuff called Modrock which is a Plaster of Paris Bandage. My main steampipe is 12mm dia pipe i first used a layer of fibreglass tape wrapped around and then a couple of wraps of Modrock. It dries very fast to a smooth finish. A couple of coats of white gloss to finish.