Which blowtorch for soldering copper pipe?

Soldering a capillary joint is a heat-control problem, not a raw-power problem. The joint needs controlled heat around the fitting: lead-free solder flows at roughly 230–250 °C ⚠, the flux must not burn off, and the pipe must not overheat. A flame that is too small never gets the fitting there; a flame that is too fierce scorches the flux and blisters the paste before the solder moves.

That is why plumbers reach for a torch that holds a steady, aimable flame at the fitting mouth — not the biggest flame in the van.

EN417 cartridge torches are light, one-hand, instant-on with piezo ignition, and the cartridge is bought locally — no cylinder, no hoses, nothing pressurised in the post. For 15 and 22 mm capillary fittings, this is genuinely enough heat: the cartridge torch is the fastest tool to set up and the easiest to control around a joint.

The trade-off is endurance. A small cartridge can run out mid-job on a long run of fittings — keep a spare cartridge in the bag and you never notice.

The nozzle, not the torch body, decides whether the flame suits the job. A soldering nozzle concentrates a steady medium flame on the fitting; a spreader throws a wide, soft flame for heat-shrink; a fine flame is for precise small work. Fit the right nozzle to the cartridge and the torch behaves like a tool twice its price.

On a standard EN417 cartridge, that means the soldering nozzle is the one you want for pipework — see the nozzle-in-kit table on the soldering torch kit page.

Big runs of 28 mm and above, heavy fittings, or copper-to-brass work in cold weather can out-run a small cartridge. That is the moment for an oxy-fuel brazing set-up — and the moment the job stops being soldering and becomes brazing. Brazing runs hotter and needs the dedicated nozzle series, so read the brazing guide before you buy.

The straightforward kit: a soldering torch kit — handle plus fine, soldering and spreader nozzles — on the standard EN417 cartridge. Keep a spare soldering nozzle for refills and a tip cleaner in the bag, because a carboned nozzle is the usual reason a torch suddenly “doesn’t get hot enough”.

Technique in one line: clean the pipe, flux the joint, heat the fitting not the pipe, and feed solder where the pipe meets the cup. When the solder flows at the mouth of the joint, you are done.

Butane cartridges: store cool, never pierce, check the EN417 valve seal before screwing on a nozzle or torch. Air torches involve no gas cylinder at all — and always check local gas-appliance rules before fitting any part (EU GAR / UKCA apply to gas appliances; our parts are spares).