Will I be able to braze a copper pipe (12mm diameter with a wall thickness of 1mm) with my benz-o-matic kid I bought with the blue canister gas, or do I need to purchase the mapp gas canister (yellow one ) for this purpose?

The blue canister will not work with anything but a basic solder joint.

The Mappgas isn't really recommended for brazing either... simply can't get the materials hot enough to guarantee a good job. If you can braze, it will take forever to do! Check out this video on the subject:

http://www.youtube.com/watch?v=wGOQkTlL1OI

For most brazing applications you'll need to rent/purchase an oxy/acetylene or oxy/mappgas set up.

Back to you...

Mark

Brazing can be done quite nicely with acetylene and a Turbohead torch. For 12mm copper use an A-14 tip (1/2")

Possible translation problem here. Do you really mean braze or do you mean what we in US call solder?

What are you connecting? If it is plumbing, 12mm is 1/2+/-", you can solder with pretty much any container gas although I use Mapp. If AC, and 1/2 is not normal size , you need to braze or silver solder and will need Acetylene or Acetylene/O2.! Use lead free solder if this is a water line!