Steve,
Converting a Roundhouse boiler to alcohol firing is OK.
I did it with my Lady Anne exactly as described, making a sheetmetal box
underneath leading around the back and sealing to the boiler shell and
backplate with silicone rubber caulk.
There is nothing destructive about doing it this way, and the added bit can
easily be removed if wanted.
You will need a steam blower nozzle in the smokebox for draught, but that
is straightforward too.
As to efficiency, this is what current Asters do, gluing thin ceramic
insulating sheet inside the metal box, using silicone as glue.
Peter Trounce.
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> From: Shyvers, Steve <[EMAIL PROTECTED]>
> To: Multiple recipients of sslivesteam <[EMAIL PROTECTED]>
> Subject: Re: Roundhouse Boiler
> Date: Thursday, October 05, 2000 4:11 PM
>
> Vance,
>
> You suggested the idea of "fitting a firebox to the rear of the RH
boiler
> and installing a vaporizing alcohol or ceramic butane burner."
>
> I would think that the efficiency of an add-on firebox would be low
because
> most of its radiating surface area would not be exposed to water.
Prototype
> locomotive fireboxes had water on multiple sides of the firebox.
>
> If one were to try a vaporizing alcohol burner, then an add-on firebox
might
> shield the wicks and stabilize the burner temperature to help maintain
the
> vaporization process. Most of the fire would be in the central flue and
not
> in the firebox. This would be a relatively easy modification to a
> Roundhouse boiler, and it could be removed if necessary. The add-on
firebox
> could attach to the existing threaded holes on either side of the flue.
>
> At one time I considered converting a Roundhouse boiler to a C-type by
> adding an enclosure around the back flue entrance. An alcohol burner
(wicks)
> would be positioned below the boiler surrounded by the firebox. I
abandoned
> the idea because I thought that the small clearance between the flue and
the
> bottom of the boiler might cause problems. (Is there a rule that governs
> this clearance?) Also I did not see an easy way to achieve a good seal
> between the firebox and the bottom of the boiler without soldering.
> Finally, I did not want to mess up the only Roundhouse boiler I had, so I
> decided that it would be easier, and cheaper, to build an experimental
> C-type from copper pipe.
>
