# Aristocraft Mikado Repair



## Charles (Jan 2, 2008)

Just a note that recently we had a AC Mike in the shop because it was not performing. We found the superheater tube was the problem: clogged with an rust blob and weak point at the nut (smokebox end) that broke once disconnected. So, if anyone founds there engine having performance issues this might be the cause.


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## David Leech (Dec 9, 2008)

RUST BLOB!!! 
Is someone NOT using stainless steel, or copper somewhere? 
All the best, 
David Leech, Delta, Canada


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## Charles (Jan 2, 2008)

David 
The new one installed by TRS is stainless steel.


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## Jerry Barnes (Jan 2, 2008)

Oh boy, something else to look forward to!


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## rbednarik (Jan 2, 2008)

The superheater on the Aristo mikado in question was made of copper pipe and was an OEM part to the engine. It developed carbonization (yes, it is not a myth!) as the copper began to break down from the direct heating cycles that the burner gave. Interestingly the plugged end was in the smoke box, right as the pipe curves to meet the steam chest tee. 

Once the problem was found, a new superheater was fabbed up with a grade 304 heavy wall (actually just the right thickness for steam service) hypodermic grade stainless steel pipe. This superheater is a hybrid type, that is the areas that saw the most heat (ie the fire tube/smokebox) were replaced with stainless, while the connection from the throttle to the end of the backhead was made with copper pipe. This was done to allow the new s.h. to fit properly without having to try and rebend the stainless tubing. This is used to take up any discrepancies between the superheater and locomotive lengths by allowing an easement for final fitting. All joints were silver brazed with ez-flo (#2 alloy if I recall). 

All in all, a good project and the new superheater should outlast the working life of the engine. Experience tells me that there is a good chance that the heavily used Aristo mikados will probably suffer from superheater failure, either through the disintegration of the copper or through plugging. Luckily the fix is straightforward and can be done in about an hour.


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## Jerry Barnes (Jan 2, 2008)

Ryan, can one get the part from you all soldered up and then just bolt it in, or does the whole engine have to be sent in?


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## N1CW (Jan 3, 2008)

Posted By rbednarik on 02 Dec 2010 09:31 PM 
The superheater on the Aristo mikado in question was made of copper pipe and was an OEM part to the engine. It developed carbonization ....SNIP..... Experience tells me that there is a good chance that the heavily used Aristo mikados will probably suffer from superheater failure, either through the disintegration of the copper....SNIP....
.
EXACTLY Gilbert's finding > 1 year ago with the SIMILAR fix applied and working FINE since.[/b]
.


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## rbednarik (Jan 2, 2008)

Jerry, 

If you can remove the old superheater yourself, I will gladly make you a new one that will be a direct fit. You have to take the inner smokebox off to disconnect the front of the SH from the cylinders, take out the burner and then disconnect the SH from the throttle body. 

Shoot me an email: tr3services{atsign}gmail.com


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## YN (Sep 24, 2008)

I experienced exactly same trouble. It can be easily understood because no steam to the cylinders ,20psi or more pressure in the boiler.I replaced super heater.


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