The flux I use for most welding is a 80/20 mix of 20mule borax and roach prufe.The roach powder is boric acid 98% and other stuff two percent.
Works extremely well for me.
Finnr
Those blowers are relatively cheap (excluding fleabay ). Keep an eye open and you may pick one up fairly cheap that is either working or is a good source of assorted parts.
Finnr
Jamie makes some real nice blanks to work from. We smith together at least a couple times a year. Though I am banished to as far from his spot as possible because my hammer bouncing drives him nuts! LOL!!
Finnr!