hi In UK plumbers mainly use soft soldering up to 3″ sizes,the bigger joints just need heating longer thats all, we add solder until it shows all round the pipe and fitting.We only use brazing for high pressure lines mainly gas oxygen nitrogen etc.I know in Oz brazing is the norm Id better start practicing before I get there.Colin.
As stated above, you just fill up the joint as for a smaller pipe joint…except it obviously takes more solder…
On pipes larger than 3/4″, it is important to have a good heat source. This is where plumbing amateurs tend to go wrong. Those DIY propane torches are not up to the job. You need to use a good old acetylene torch.