Increasing efficiency of water fire extinguishers:
The common 2.5 gallon pressurized water extinguisher is a common tool in our inventory at a fireworks show to deal with burning cakes, or grass fires. This can be a fairly common occurrence. But there is a simple addition to the extinguishers that we can make when recharging them, that will greatly increase their effectiveness.
By adding one cup / 8 fluid ounces / 250 ml of common household dish soap (Joy, Palmolive, budget brand, etc) to the extinguisher after the 2.5 gallons of water, then the air charge, we have changed the surface tension of the water. (HINT: Water first then soap, or the amount of bubbles you create will be unimaginable)
This change in surface tension will improve the ability of the water to penetrate things like grass, wood and cardboard for much more effective fire suppression.
On several fire department web forums, comments suggest this more than doubles the effectiveness of the fire suppression. Google for yourself and see – “2.5 gallon water extinguisher, dish soap”
Try it out next time you are recharging one and see the difference.