Water welders are very good for gold , platinum. However for silver
and normal steel and low alloyed stainless steel they are of no good.
The reason is that these welders could not be adjusted to a reducing
flame. overdose of gas). In silver you get than copper oxides, and
steel will burn away and can get a problem with hydrogen brittleness
in the steel. But if you could build a type which can dump some oxygen
or can be used with some additional gas, it will be a nice gear. .