Making of double walled piece 2

I chose to work on simple shape, to keep the metalworking practise as easy as possible. Still, I wouldn't have believed how hard it can be to solder two walls together, handmade accurately.

It took me four rounds to solder the base on to the two walls. I had to consider, that heating the metal would create hot air, which needs to escape. I drilled a little hole for the air to escape, on to the base sheet, just between the two walls. This way I ensured not damaging the metal. If the hot air would get trapped between the metal walls, it would retract the metal, when the air is cooling down. Serious damage would appear on the surface. Also, if I would re-heat the vessel without an air hole, the vessel would explode, because the hot air would not be able to escape. 

Silver solder pellets placed along the inside and outside seam. Rouge and mineral oil brushed on to the existing solder line. 

The piece after heating. Natural oxidising appearing on the surface. The metal became so hot, that the oxidising has turned into ash that just flakes off.

One can see, that some of the solder pellets hasn't melted inside the vessel.   

Here, I have marked the spots where solder is needed to fill the gaps on the seam. 

Aaargh, not easy! Due to uneven heating, the solder has melted all over the place, not on the seam, where it should have.  Plenty of sanding is now needed...