I got in one of these tiny torches the other day to experiment with brazing aluminum in tight spots and one of the techs walked in and asked “what type of torch is that” to which I answered “It’s oxy/acetylene”, he picked it up and looked at it a bit then asked “Does that get hot enough to braze copper?”
It’s actually a tough question to answer simply
When we say does something get “hot enough” we often mean that the TEMPERATURE is high enough to melt solder or brazing rod, but heat is both an intensity (temperature) and a quantity (BTUs), so while this tiny torch is certainly high enough temperature to melt a rod, it may or may not be enough BTUs to heat up the base metal being joined.
The temperature of the flame is primarily dictated by the fuel or fuels being burned as well as the oxygen mixture. The BTUs depending on the pressure being used and the size/type of the tip.
Most torch manufacturers will list the size of the (copper) pipe that the tip is rated for as well as the proper oxygen and acetylene pressures for the task.
So, heat is both a quantity (BTU) and an intensity (Temperature) and when we say how hot or how cold it really depends on what you mean. But to answer the question… Yes ,you can braze copper with the tiny torch, so long as it is small tubing.