Blue sheet metal.

Hello everyone,

I have a question about the sheet metal covering of steam cylinders.
Stuart engines only offer this black aluminum sheet metal these days. I often use brass sheet metal. But the correct choice would be blued sheet metal. That is, steel sheet metal that is heat-treated. I know the sheet metal needs to be polished and free of grease before the heat comes into play. But how do you do it exactly right?
I'd like to do it this way on my Stuart No. 7.
(Maybe Sanjay on his No. 5 😉 )

Michael

Hello Michael

'Russian Iron' was the traditional material of choice for cylinder and boiler cladding. I don't think it has been manufactured for years due to low demand. Brownells are well known gunsmithing suppliers, they sell a variety of chemical blueing/blacking kits for gun barrels etc. which may help you to produce your own faux 'Russian Iron'.

Cheers

Mike

I agree the blued lagging looks much better, I have 'blacking' chemicals for brass but not seen 'blueing' chemicals. The Stuart lagging these days is Ali painted black isn't, so not sure if you'd have to use copper sheet and then blue that?

There are a number of chemicals available from the gunsmithing market, though they only work on certain metals. There are a lot more available from the jewelry industry, a whole range of colors that can be applied to copper/brass/etc.

Great video! I went and looked at a number of his other videos too, fascinating stuff on making armour, lots is applicable to models too.

tghs, thanks for the video.
It looks like it's possible.
I'll have to try it.

Michael

A standard propane torch will give you a bit more control over the speed of bluing. Take a leaf out of the watchmaker's bible and blue on a bed of small chips of metal (think contents of swarf tray) this will support the metal and prevent a heat sink cold spot like he had in the centre of his piece.

Be aware that spraying oil on a blue hot metal surface will produce some nasty (possibly dangerous) fumes. I dump my pieces in a dish of oil rather than squirting it - this also causes nasty fumes  what ever you do DO NOT try reheating the metal once it is covered with oil.

It is not difficult blueing. I suspect what Stuart supplied in the later years was chemically blued 

Jo

Hello Sanjay, I suspect Stuart uses black anodized aluminum sheet these days.
I have a Stuart 4 with this aluminum sheet, and the 10 V is the same. Only a Stuart 9 uses blue steel sheet.

I also think the sheet has to be bent into the correct shape before blueing it. Because it might look like spring steel afterward?

Michael

Hello Michael

Do you have a heat treatment oven by any chance. That would give near perfect temperature control.

Mike

Quote from: Michael S.Hello Sanjay, I suspect Stuart uses black anodized aluminum sheet these days.
I have a Stuart 4 with this aluminum sheet, and the 10 V is the same. Only a Stuart 9 uses blue steel sheet.

I also think the sheet has to be bent into the correct shape before blueing it. Because it might look like spring steel afterward?

Michael

Yes I think you're right about the anodised aluminium, my Stuart no.9 also came with the black, but it was a modern kit rather than an old kit

Yes, Mike, an electric kiln with firebricks and simple electrical controls. That would be one way to achieve a consistent temperature.

Michael

a simple heating with a small butane torch of a thin steel sheet followed by a quenching in old oil will give the characteristic dark blue color of the cladding of period engines and tinplate toys...

Reeves in the UK used to supply sheets of nicely blued steel for lagging, I used it for my ST No 1 vertical engine.  The colour is attractive, but it is in effect blued spring steel, and needs to be well secured to the cylinder ...

There was some discussion of Russian Iron on this forum a couple of years? back, a few lucky members had a secret hoard ..  Pity that it's not available, as it does look very well on an engine.  My 1967 purchased ST No 10 engine castings came with a small swatch of the Russian :  and the older Stuart Turner castings for the Triple Expansion engine which I am just starting to tinker with, soleplate and columns machined, has got the Russian iron sheets also.  The new price written on the complete two package set of the castings is £57 ... !  ( But I bought them new s/h, forty years ago,  for £35 ). Dave

I’m confused does blueing produce blue or black? I remember my motorcycle exhausts and they were definitely blue!