Our friend Theo is restoring a Harley Davidson W from 1919, this has a rather rare boxer engine. The engine is already rebuilt but the tank was still missing, so we will be making a new tank from skratch.

PART 4

While working on the last panel of the tank, the planishing hammer seized up. Upon closer inspection it turned out that the piston had broken and the cylinder was badly damaged. As we needed this tool to finish the tank, we now had to fix the planishing hammer first.

Aad decided to make some extra parts so he ended up making 3 new pistons and 3 new cylindes. The pistons were hardened by first heating them to 810 degrees C, then quickly cooling them off in oil. This gave us a hardness of 64 Rc which was a bit too much, so the parts went into another oven at 250 degrees C and were then allowed to cool slowly. This resulted in a hardness of 54 Rc, perfect!
The new cylinders were honed to the correct diameter and the planishing hammer was reassembled and back in business.