I am trying to find a bonding agent instead of silver solder? the application is control rods for model aircraft. Answered

You really have a lot of choices depending on why your using solder.

Music or piano wire normally used for control rods comes in meter lengths in the Uk plenty long enough for most RC aircraft.

Mechanical joints - Strip the plastic off a connector block intended for electrical wire - Use the brass connector inside to connect the control rods.

Crimp a bit of brass tube over both rods.

Use epoxy glue

I have joined control rods with little more that electricians tape - there isn't a lot of stress on them. Although this can slip over time.

Use standard electrical solder and a soldering iron.

Try JB Weld steel epoxy putty.

Are you flying too close to the sun like Icarus of the Grecian story ?

Depends on the type of connection, for slide in rods super glue is good enough.

For other connection either resin or this metal putty to make quick repairs on your car, Knet-It is one brand.

But with small brass parts on models I actually prefer normal solder, either the acid filled type or standard electronic solder (requires the light sanding of brass brass parts before soldering).

Gives the best finnish and is much easier than brazing with a blow torch.