I have a Weller 260/200Watt soldering gun I use for my silver soldering. Brazing is a higher temperature affair than soldering, but I think flux is flux. It is an acid that allows the solder to bond better. It comes in paste or liquid. I use the liquid, but it is sold as "soldering flux"

Be sure to clear it off afterwards. I buff my joins up with a stainless brush or the wire wheel from my Dremel.

A friend charred the cockpit of his Tiger Moth using a torch to solder the cabanes. Be sure you protect the wood for the first foot or more of the torches' path.