Bells, pistons and all conical and cylindrical tubing on the instrument should be made from a single offcut with a lengthwise seam and hard soldered.
 

I bring the individual straight parts into the shape required for an instrument by bending them.
 

To do so I use lead that has been heated to approx. 330°C and then, for example, fill the bell with it.

As soon as the lead has cooled off in the bell, I can start the bending work.

To do so I use a wooden bending block.

I bend it only until small creases appear in the sheet metal.

I then rest the bell on a rubber support and hammer out the creases with a forming hammer. This process is repeat as often as required to achieve the desired shape.

I hammer the still uneven surface with further forming hammers to make it as smooth as possible.

To achieve a very smooth surface, I use stamping tools in the next work step.

This means of bending allows me to produce very thin sheets (down to 0.30 mm unfinished sheet). But even with material thicknesses of, for example, 0.45 mm this craftman's method can have a decisive effect on the response of the future instrument:
The material is slowly stretched (outside) and compressed (inside)


By working the material with forming hammers made of polished steel and stamping tools made of polished cast iron, the material (wall) is densified.
 

When the lead has been melted out of the individual parts, the parts have been buffed and polished, I am left with very light instrument components made of thin-walled sheet metal that has been densified.

When after assembly the wind player blows into the instrument, he sets the air column in the instrument vibrating. These propogate by hitting and rebounding off the tube walls. When the vibrations encounter a thin, hard material, they are propogated faster and more easily; the instrument has a better response.