This is the smoke box lid. The chimney comes out of the middle but it requires another flange.
First a video. Click on the arrow. Listen to my dulcet tones.
The setup on the hydraulic press. The copper cap has been annealed, and a 19mm hole drilled to just admit the steel taper pin.
After pushing the steel pin with 20 tonnes pressure. Re-annealing required.
After the next 20 tonne push. Re- annealing again required.
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.
and a 10 minute soak in 10% sulphuric acid…
—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.