OZONE ATTACKS RUBBER- AN EXPENSIVE LESSON

I had an expensive lesson on the destructive effects of ozone on rubber recently.
Ozone occurs naturally in the air, commonly after electrical storms, of which we’ve had a few lately.

But in this case, the destruction originated from an electric motor, immediately under the rubber seal that was supposed to keep the water in my pool’s heating system. What’s that got to do with tyres? Well, when tyres are stored, like on your caravan or on a seasonal piece of farming equipment, care should be taken to protect them from sunlight, and electric motors.

Otherwise, ozone from electric motors will attack the rubber, BUT ONLY WHERE IT IS STRETCHED!
Wide lacy cracks appear, and grow very quickly, as shown in the photo. The victim is shown in the front of the first photo, a new seal in the background. This appearance is typical.

So the temperature sensor was ejected, a geyser of salty water covered everything for 3 metres around, the pumps eventually ran dry, and an expensive repair bill resulted. All this for a 50 cent rubber grommet in the wrong place.

When removed from the pipe, the side of the seal inside the pipe was in A1 condition. This is shown in the second photo- it’s been turned over. There’s no ozone in the water, then- only chlorine.

Another place where this type of cracking occurs is in the bent rubber hoses in your washing machine. That can do a lot of damage too, replacing tiles, carpet, timber, coreboard cupboards, and maybe carpets too.