Bronze welding your spaceframe

[Terrapin]

This is the correct specification for your bronze welding rods. These are by UK manufacturer Sifbronze.

SIFBRONZE No. 2 (9% Ni)
BS: 1845 CZ8, 1453 C5
Nearest Equivalent Standards: DIN L-Ns, AWS RBCuZn-D

A high quality, free flowing rod containing 9% nickel which produces an exceptionally strong joint on cast iron, copper alloys, stainless and alloy steels. It has excellent wearing properties and is recommended for building worn components like gear teeth, bearings and valve seats, since it work hardens. The high strength characteristics make Sifbronze No.2 ideal for tubular structures, brazing cutting tips and as a general maintenance alloy. Use Sibronze or special purpose flux.

48 Cu
10 Ni
0.3 Si
Bal Zn

Cheers
Rob

[twentyover]

Does this require any unique or particular fluxing agent? can you use it with Jet Flux? (you percolate the oxygen through a liquid as the torch is running, and the fluxing agent in entrained in the oxygen.)

Also, anyone ever try brazing with a TIG torch (I'm guessing you'd run carbon dioxide as the shield gas, to emulate the shield gas generated by the combustion of acetelyne an oxygen.) Using the torch as the heat source? Yeah, I've got one, and no gas welding equipment

[Terrapin]

You can use either a suitable (get rod manufacturers recommended flux) powder flux but this leaves you with a residue to clean off afterwards. Alternatively you can use what is termed a Gasfluxer or Autofluxer where the fuel gas (Acetylene) is passed through a liquid flux which usually turns the welding flame green in colour. This is an effective method to use and avoids clean-up afterwards.
You can bronze weld with TIG but I have no personal experience doing this. You can now also get bronze welding wire for the MIG, I believe it is very expensive.
Rob