Multicore solder is used for soldering electronic boards and components and Brass Etched Kits.

This is a solder with very similar makeup to white metal kits with a similar melting point you will melt white metal product, so would if used give a welded joint (melt the kit and product together) Very strong and resistant to higher temps but difficult to use on white metal.

We use multicore to solder together Brass Etched kits (advantage you cannot melt brass with soldering iron).

It is fairly easy to solder brass together, 'dry' run joint and check for fit and position. Paint on a little low melt flux onto joint.  Using a clean solder tip put a small onto tip place on tip and draw down the joint. The solder will flow into joints. For long joints I tack up small bits with solder down joint and then place iron and solder to joint and draw down lenght flowing in more solder as required. The solder will fill joint as well as fixing. NOTE it is easier to add more solder than to try and remove too much solder.  Repeat for all joints required then simply wash is warm soapy water to remove flux residue. Undercoat and paint as required.

Trick....if you haven't done this before try soldering the scrap parts of brass from the kit (the frame holding parts in place. Practice makes perfect.