Repairing Leaky Water Tanks

The article below outlines some simple DIY methods of repairing cracks in water tanks. For cracks on polyethylene water tanks (or ‘plastic’ tanks) we recommend that a plumber be called to repair the crack using the plastic welding technique which involves melting a strip of polymer into the crack thereby forming a durable, neat repair.

crack in water tank
Have you noticed an increase in your water bill? Or perhaps the ground around your water tank is constantly damp? This could potentially mean you have a leak in your water tank. It is important to fix leaks as soon as you find them, before the problem worsens. If the leak is minor, there are many ways you can repair it yourself. The following tips will guide you through some of the things you can do to repair water-tank leaks. These tips are not applicable for large leaks, or when the damage is caused by hardware failure. Seek out professional advice for such damage.

Check For Cracks Around The Piping

Often, leaks can occur as a result of old piping that has worn out due to too much sun or weather exposure. This in turn can cause the area around where the pipe connects with the tank to blister and crack. If this is the case, it is easy to repair yourself.

Clean The Area Around The Damaged Surface

You need to ensure the area around the cracks is free from dirt and grit before you can go ahead with repairs. This does not mean using water and a sponge. You will need to use sandpaper to lightly scratch the surfaces. This will roughen the surface and make it easier for the adhesive to stick.

Get Rid Of Any Residue Before Applying Repair Products

Sanding the affected area will often leave dust or tank particles around the affected area. It is important you re-clean the surface using a wet substance before beginning your repairs. Using a cloth and spirits (or alcohol), wipe the area and ensure all residue is gone.

Use Gloves When Making Repairs

Avoid touching the area you are working on with your bare skin. Not only can the cracks or tears be sharp and dangerous, but your body oils are more potent than you realize. The oil from your skin can mark the tank. This substance can affect the sticking properties of the various adhesives. Use gloves to avoid this, and to protect your skin from sharp surfaces and toxic substances.

Repair Using Fiberglass and Fiberglass Resin

One way you can repair minimal damage in water tanks such as cracks or tears, is by using fibre glass sheets and resin. Apply the fiberglass sheets in single layers on or around the crack. In between each layer, apply the resin. Use plenty of resin per layer. Let each layer dry a little before applying the next one. Ensure you are using those gloves as the resin can be sticky and toxic.

Repair Using Putty

Another way you can repair a small tank-leak, is by using putty. You will need strong putty, preferably one with steel. These are generally labelled steel putty. Simply apply a generous amount of putty to the crack or tear and let it dry for the recommended time.

Use Both Methods for Slightly Larger Tears

For bigger cracks, don’t hesitate to use a combination of the Fiberglass, resin, and putty. This will add extra strength and ensure the crack is securely covered.

Keep an Eye Out For Further Leaks

Once you have applied the above methods, keep an eye out for further leaks. If water continues to leak out, you may have to replace faulty hardware. You will need a professional to do this. Checking regularly for further leaks will also allow you to see if the resin and/or putty has worked, and to catch any other tears before they become irreparable.

Water tanks are often subjected to all kinds of weather conditions. Naturally, this can result in general wear and tear, and eventually water leaks. By checking for damage regularly, you can repair small cracks or tears yourself and avoid further damage. The above tips will guide you through how to do this, and the things to look out for to ensure your water tank is kept in the best possible condition.


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