Practical tips for welding: 3 reasons for not using water as a coolant for welding

Posted by Florian Görlitz on Nov 3, 2020 2:32:04 AM

What do you actually use to cool your welding torch? Is water from the regular piping system running through the cooling system of your power source or have you filled in coolant? And do you often have to cope with torch failures? If this is the case, the choice of your coolant could provide information about the reason for the frequent torch failures. In fact, water is often used as a coolant during welding. Why this is not a good idea at all, and why it can even cause torch failures, is explained in this blog.

3 reasons why water should not be used as a coolant during welding:

1. Water speeds up decomposition process

Like any substance, water has a conductivity for the transmission of electricity. Colloquially, the term conductance is also often used in this context. The electrical conductivity is indicated in Siemens per meter (S/m) or micro-Siemens per centimetre (µS/cm). Another form of conductivity is electrical resistance in the unit Ohm. At the same time, both values are dependent on each other: the higher the resistance, the lower the conductance – the same applies vice versa, of course. Water has different conductivities depending on its source:

Ultra-pure water ≤ 1.1 µS/cm at 20 °C – it has virtually no conductivity because it contains almost no foreign substances. Only these substances dissolved in the water, such as chlorides, sulphates and carbonates, make the water conductive.

Tap water = 250 to 1,000 µS/cm – depending on the hardness level of the tap water pre-cleaned by the waterworks.

Generally speaking, the higher the conductance in micro-Siemens, the more saturated the water is with particles and the more conductive the water is.

Returning to the coolant ... Let us assume that we use ordinary tap water as coolant in the cooling system. When electricity flows through water – as is the case when a liquid-cooled welding torch is used – a chemical reaction occurs. Since materials with different electrochemical potentials are used in the cooling circuit, a dissolution process takes place: so-called »base« materials such as brass are dissolved and transported towards the »noble« materials such as copper.

If, for example, a liquid-cooled MIG/MAG welding torch is cooled with water, and thus it flows past a current-carrying cable, connections, cooling pipes, etc., this causes the decomposition process. As a result, particles are released which can clog the torch and lead to its failure. This is also referred to as electrochemical corrosion. To put it in a nutshell: Cooling a welding torch with water destroys the torch – but also as a consequence the power source and other components of the torch system involved. Therefore: Water as a coolant is definitely not recommended!

2. Frozen water causes bursting

The second point, which also should not be disregarded, is the fact that liquid-cooled welding torches are also used outdoors and are also transported in winter. If there is water in the cooling circuit, this inevitably leads to the bursting of the torch and cooling system components at temperatures below zero. Perhaps you have wanted to put a drink in the freezer for a short time and then forgotten about it. After such a mess, which leaves a burst bottle behind, this usually doesn't happen a second time.

Some torch manufacturers also rely on distilled water to cool their torches or offer coolants mixed with distilled water. The problem is that distilled water does not contain antifreeze and is therefore not optimal either.

3. The torch periphery is also destroyed

Not only the welding torch itself, but also all equipment and parts connected to the cooling circuit or cooling system are exposed to electrolysis and can be destroyed over time when using water as a coolant. Water in such a system can cause malfunctions and loss of efficiency up to total failure. Typical signs of such a decomposition process are brown coloured water, suspended solids or sediments in the cooling liquid or even a clogged pump.

If you love your torch

... never use water as coolant. A technically suitable coolant must be used to cool a liquid-cooled welding torch. For this purpose we recommend the BTC series (BINZEL Torch Cooling) from ABICOR BINZEL in the form of BTC-15, BTC-20 NF and BTC-50 NF.


Depending on the type, these can be used from minus 12 to minus 45 degrees Celsius and, with the exception of the BTC-15, meet the NF standard, i.e. they are non-flammable. All three coolants have an extremely low conductance value of maximum 4 µS and thus reduce the electro-corrosion of all metal parts of the cooling and torch system. This protective effect means that all system components have a long service life. So please do not experiment with distilled water from the DIY store.

By the way, this is also the reason why we do not use the term water-cooled torches, but liquid-cooled welding torches. So that no wrong conclusions can be drawn.

Why should the coolant be changed regularly?

The recommendation to replace coolant once a year is very often given. Depending on the frequency of use and the duty cycle of the welding torch, however, this can be much too late. Because: Coolants age. To avoid reaching the point where the recommended conductivity is exceeded, it must be checked regularly. For this purpose there are measuring devices such as the Primo 5 from Hanna Instruments, which ABICOR BINZEL also offers. Simply dip the meter into the filler neck for the coolant at the cooling unit or power source and read the measured value on the display. Please remember to calibrate the measuring device regularly.

How often should the conductivity of coolant be tested?

You should check the conductivity of your coolant between once a month and once a quarter depending on the duty cycle and frequency of use. At which values an exchange of the coolant is recommended is shown as follows:

Therefore, if you regularly check the conductivity of your coolant, you are on the safe side. Do you have further questions about coolant? Please feel free to contact us!

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