Another convenient fixture of an experienced welder to simplify the work can be made independently. For crafts, you need a pair of thick strips of metal, neodymium magnets, two thick washers and rings of the same diameter.
Magnets must be placed in one of the strips, for this a hole of such a diameter is made so that they fit tightly into them. So that the magnets do not fall out the edge of the metal is better to tilt in a circle. The second strip after completion becomes a clamp.
The strips are connected by welding with metal rings, which in turn are pulled together by a bolt. On one of the washers, notches can be made from the outside to indicate the angles for welding.