On Saturday, February 15, 2014 2:18:02 PM UTC-8, oldnverygrey. wrote:
Am making flowers. Used aluminum mesh and galvanized screws and nuts and

want to put to a rod of galvanized steel. Can I solder.

Yes, kinda. There are 'aluminum solder' compounds, with aluminum/zinc/tin/lead
and maybe other stuff (cadmium?) that will, if you carefully wire-brush the
alumium etc bright, usually bond. Use a propane torch, not an iron.

There are fluxes that work with aluminum, but (if memory serves) they
use fluorides, and lots of ventilation is recommended.

It may be useful to tin part of the surface with the aluminum solder, then
after assembling use a 'regular' solder (tin/lead or tin/antimony) to
complete the joint. The aluminum solder isn't forgiving of temperature
range, and cannot be held liquid long.