I have used these rods a few times takes a bit of practice to get right but when you do it is a very strong joint.
I bought a Mapp gas torch and Stainless steel brush from Bunnings for under $100 Aus and got practicing with a plan to making Bumpers for one of the trucks.
Just make sure your brush is Stainless steel I rushed a test one day and used a brass brush the joint looked good but let go with a bit of pressure
try the link and give it a go.
https://www.youtube.com/watch?v=3SBfP4_i1Go