Cladding material

It’s time to clad my small 7 1/4 loco boiler. The barrel is 12” long and dia. 6”

insulation will be a thin sheet of suitable material (1-3mm]

question is, do I use steel or brass. I have some 24 g brass in stock but it seems a but flimsy although it is about the size recommended by Martin Evans in his loco construction book.

Brass can be difficult to paint, in the long term while steel is a lot easier, but there is the possible problem of rusting due to weeping clacks or dribbling safety valves

in steel I would use 22, or 24g and in brass I think 20 or 22 would be better. Cost is not an issue.

Is there anybody with any experience of using steel, or do people think it’s a no no?

Steel would be protoypical, but prone to rusting. Might be better if you could blue it. Presumably the blue oxide film gives better protection from rusting.

(c/f "Russuian iron" for cladding of boilers on full scale locos in the early days of the 20th century. )

Can you get black steel in sheet form?

Brass would be less likely to corrode, but be more expensive.

Howard

I have used steel, of a type known as zintec which is zinc plated on both sides. It is easy and cheap to obtain and is used for the casings in refridgerators and washing machines etc. and takes paint very well.

I cannot advise on longevity as I only kept the engine for 5 or 6 years.

Brian

I’ve clad my previous two boilers with thin stainless steel having bought a couple of cheap pedal bins for the purpose.
Just need to be careful you can get a big enough piece out of them whilst avoiding any holes, there is also the benefit that you get a nice rolled edge at one end. From memory the 4.5” dia boiler was done using an 8” round bin which cost about a fiver.

D builder, Interesting, I hadn’t considered stainless.
Brian I thought galvanised steel was difficult to paint, all to do with atomic bonding You see a lot of painted galvanised railings with sheets of paint falling off

Has anyone tried Farm Oxide paints on their models? Available in many colours if one shops around - albeit in larger cans. Straight to metal, silk finish and obviously pretty robust and easy to brush.

pgk

If you make it from steel sheet why not get it zinc plated after you have cut and fitted it, that way the edges are plated as well?

Galvanising (and electroplated zinc?) is not very receptive to ordinary primer, but appropriate primers are readily available.

This all seems a lot harder than just using Brass. It's really not that expensive when you consider its the finishing touch and will be one of the most visible parts of the locomotive.

I used Acid #8 (I think its called) etch primer and have had no problem with flaking or similar; I then painted used an automotive enamel which went on like glass on the boiler barrel. The only places I had issues was the side tank where my son painted over our decals with a varnish which subsequently reacted with the enamel and wrinkled.

I think the paint not adhering to galvanised steel is because of a poor process. Cars all use zinc coated material and peeling paint is not a problem. Brand new galvanised steel often feels a bit greasy and I think it needs a good clean and suitable primer.

Mike

Galvanised iron usually takes paint better if left out to weather for a while - although that probably wouldn't be a practical solution for a loco.

Rob