scale insulation of steam pipes

[Tony MartyrParticipant @tonymartyr14488]

[Tony MartyrParticipant @tonymartyr14488]

I need to insulate the steam transfer pipes on a triple expansion engine. Full scale practice I remember from long ago was to wind asbestos rope tightly round the pipe and then use an asbestos-chna clay (?) plaster to give a smooth surface that was later painted. I used to blow the dried plaster off my overalls with an air-line!

I have used an automotive insulating tape on track cars but it is not suitable for 3/8 and 1/4 inch copper tube.

Any ideas?

Tony

[FMESParticipant @fmes]

I used a fibreglass cord seal from a boiler, it was about 3mm in diameter, wrapped around the copper pipe and then sealed with plaster of paris.

Its still good after 25 years on my loco.

Nearest I can find is **LINK**

hope this helps.

[Phil PParticipant @philp]

I hope no one minds a link to another site, but there is some information on pipe insulation here.

**LINK**

Phil

[JasonBModerator @jasonb]

At these sizes you won't get a lot of insulation value so may as well go for the look rather than effect. One common method is to find a suitable thread, string, cord, etc and wind that around the pipes and then coat with PVA or an Acrylic medium.

You could also try one of the reinforced modeling clays such as DAS which can be shaped & moulded over the pipe and then painted when dry

[Sub MandrelParticipant @submandrel]

At 1/12" I used string and a thick dose of white paint*. The end result my be a little fuzzy for some!

Neil

*Look closely at the picture and it will be clear I don't understand the concept of thin paint…

[jason udallParticipant @jasonudall57142]

Love the scale pallet

[Tony MartyrParticipant @tonymartyr14488]

Thanks to all – I'm going the fibreglass string (from wood-burning stove seal) plus the paster of Paris. Since this is going to be a working model I wanted to avoid heat discolouration of the insulation on the feed to the stop-valve and the IP to LP leg. The LP to Condenser pipe can remain unlagged since it should run cool if I can pull a part vacuum.

I remember how much easier and dangerous it was to find a steam pressure leak than a vacuum leak – nowadays I presume its done with a cleaver microphone device

Tony

[ChrisHParticipant @chrish]

If it was a superheated steam leak it was very dangerous indeed – you cannot see the leak only hear it, and if you touch it it just cuts right through you, so it was hunted down using a bit of rag tied to the longest gas welding rod or similar that you could find and very very careful probing!

Chris

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