6″ Vertical Boiler. The final flange on the smoke box.

by John

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This is the smoke box lid.  The chimney comes out of the middle but it requires another flange.

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So this is the cover, with the extra flange.  How did I make it?  Read on…

First a video.  Click on the arrow.  Listen to my dulcet tones.

 

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The setup on the hydraulic press.   The copper cap has been annealed, and a 19mm hole drilled to just admit the steel taper pin.

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After pushing the steel pin with 20 tonnes pressure.  Re-annealing required. 

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After the next 20 tonne push.  Re- annealing again required.

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After the third annealing and a final push with the press.   A bigger press might have done this in one step, but at the risk of the copper splitting. 

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and a 10 minute soak in 10% sulphuric acid…

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—and a tidy up of the edges in the lathe.  The intermediate piece is pushed into place, ready for silver soldering.   A couple of circular flanges to be soldered in place to hold the chimney.

Considering the force exerted on the wooden forms, I would not have been surprised if the wood had split on the hydraulic press.  But it held up.  Even so, another time I would be tempted to make the forms in steel.