How to Repair Plastic Rainwater Tanks?

Fill it up with plastic rainwater.

If you're dealing with a few cracks, try patching it from the inside. Make the patch from a similar material as the tank, and attach the patch with ordinary machine screws, with nuts and washers. Use lots of gasket sealer between the patch and the tank, and you might also cover the screws with gasket sealer to prevent rust.

If the tank is fiber glass, forget the screws. Just get to the auto parts store and pick up a fiber glass repair kit. Use gloves when working with fiber glass resin.

Now, if the tank has failed because sunlight and pollution have weakened it, will keep on cracking and this is going to be a waste of time and money.

Hello Friends,

1. Drain the water from the plastic rainwater tank so that the water level is 2 to 3 inches below the repair area.

2. Determine the type of plastic your rainwater tank is made from by finding the three-letter identification code stamped on the surface and then referencing the identification code in the plastics identification guide. In the identification guide there will be a welding temperature listed along with the plastic's melting temperature.

3. Set the heat of the plastic welder, turn the plastic welder on and allow the plastic welder to warm up while you prep the repair area.

4. Put on your safety glasses.

5. Create a 1/16-inch groove over the repair area with the carbide beveling tip attached to the die-grinder. Run the groove 1/2 inch past each side of the repair area. This will ensure that the stress is relieved from the repair.

6. Hold the speed tip of the plastic welder on one end of the repair area and feed a length of plastic filler rod into the rod guide of the speed tip.

7. Apply downward pressure on the plastic filler rod and pull the plastic welder toward you. Keep a constant eye on the area where the plastic filler rod meets the surface of the repair area. If you notice the surface of the repair area turning brown, increase the speed you are pulling the plastic welder. Slow down your pulling speed if you notice there is no bead of melted plastic flowing in front of the area where the plastic filler rod meets the surface of the repair area.

8. Clip the plastic filler rod with the side-cutting pliers when you reach the end of the repair area. Fuse the end of the plastic filler rod to the surface of the plastic rainwater tank.

9. Allow the welded area to cool to air temperature before allowing any water to enter your rainwater storage tank.

Thanks and Regards
Michael Earl

Hello friends,

Plastic water tanks come in all shapes and sizes and are the sort of thing that see a lot of abuse. They are regularly damaged, and some are not so easily or cheaply replaced. Also, some people just have the old-fashioned, sensible attitude that useful things should be fixed, not thrown away. Patching up a plastic water tank is a simple process that can be done inside of 10 or 15 minutes.

Thanks and Regards
Michael Ellgren

Hello Community,

Plastic rainwater storage tanks can become damaged with age. When a plastic rainwater tank cracks, you need to repair the crack to conserve the rainwater and to keep the crack from growing to a point that you need to replace the tank. To create a permanent repair to your plastic rainwater tank, you need to fuse the crack with heat. A hot air plastic welder will fuse the crack, creating a strong repair. Here are some instructions for repairing a plastic rainwater tanks.

1. Drain the water from the plastic rainwater tank so that the water level is two to three inches below the repair area.
2. Determine the type of plastic your rainwater tank is made from by finding the three-letter identification code stamped on the surface and then referencing the identification code in the plastic identification guide. In the identification guide there will be a welding temperature listed along with the plastic melting temperature.
3. Set the heat of the plastic welder, turn the plastic welder on and allow the plastic welder to warm up while you prep the repair area.
4. Put on your safety glasses.
5. Create a 1/16-inch groove over the repair area with the carbide beveling tip attached to the die-grinder. Run the groove 1/2 inch past each side of the repair area. This will ensure that the stress is relieved from the repair.
6. Hold the speed tip of the plastic welder on one end of the repair area and feed a length of plastic filler rod into the rod guide of the speed tip.
7. Apply downward pressure on the plastic filler rod and pull the plastic welder toward you. Keep a constant eye on the area where the plastic filler rod meets the surface of the repair area. If you notice the surface of the repair area turning brown, increase the speed you are pulling the plastic welder. Slow down your pulling speed if you notice there is no bead of melted plastic flowing in front of the area where the plastic filler rod meets the surface of the repair area.
8. Clip the plastic filler rod with the side-cutting pliers when you reach the end of the repair area. Fuse the end of the plastic filler rod to the surface of the plastic rainwater tank.
9. Allow the welded area to cool to air temperature before allowing any water to enter your rainwater storage tank.


Best Regards,
John Marrison

Why, how odd. You've give exactly, and I mean exactly the same advice as Michael Earl about two posts above. You must be feeling pretty satisfied with yourself right about now.

There are lots of shapes and sizes available in water tanks. And sometimes it is vary difficult to replaced it. But I want to suggest you a process to solve this problem is Patch up.