How to Repair a Leak in Your Small Pond

I built a very small water feature in my back garden several years ago. It is essentially a pond in a black plastic bucket. Retailers would call the bucket a “hard sided pond liner.”

At some point this spring my pond liner sprung a leak. I didn’t know exactly where the leak was but almost all of the water disappeared. I cleared all of the rocks and the pump out of the pond, and carefully searched the bottom to find the hole.

I dried the bottom of the pond liner off with a rag and slowly shone a light back and forth, looking for a glimpse of a crack or tear.

I took my gloves off and ran my bare fingertips over every inch of the bottom, trying to feel the gap that was letting water out.

I couldn’t find a leak anywhere.

Finally, I dismantled all of the decorative rocks surrounding the pond and pulled the liner out. I used a hose to spray the mud off the outside and, within seconds, I could see the hole:


The gash that had somehow been invisible on the inside was clearly protruding on the outside.

I’ve repaired leaks in my rain barrels previously so I knew that I could easily fix this hole with a product called JB WaterWeld*. This product is a two toned putty–a core of dark grey putty surrounded by lighter grey putty. When the two substances are mixed together a reaction occurs and the product bonds to most surfaces, forming a water tight seal.


Using WaterWeld to Repair a Leak in a Hard Sided Pond Liner

I cleaned the worst of the mud off of the pond liner and dried it off a bit. WaterWeld will work on wet surfaces but dirt impedes its ability to stick.


The supplies I used for this project were a pair of disposable gloves, a putty knife, and a tube of WaterWeld.


You can watch this video to see how I patched the hole in my pond liner, or scroll down to see the written instructions.

To use:

  • Put on a pair of disposable gloves.
  • Take the WaterWeld out of the tube and open the clear plastic film wrapping the putty.
  • Use the knife to slice off a piece of WaterWeld big enough to fill whatever hole needs patching.
  • Wrap the remaining putty back up and put it back in the tube so that it doesn’t dry out.
  • Knead the piece of WaterWeld until the dark and light grey materials are fully mixed. When sufficiently mixed it will start to emit a chemical odour and give off heat.
  • Smush the WaterWeld into the hole that needs patching.

Since this product can even be used underwater (not something I’ve tried yet) there is no need to wait for it to dry or cure. I filled my pond up within 15 minutes of patching it and the repair held beautifully.


There are likely other products available that work in a similar manner but WaterWeld is the one I stumbled upon and have found to be quite handy. The most difficult part of using it is getting the putty to stick to the surface you want to patch and not to your gloves!


*Note: this is not a sponsored post-I have not been paid or compensated in any way by the makers or marketers of JB WaterWeld. However, as with many of my posts, some of the links on this page are affiliate links, meaning, at no additional cost to you, I will earn a commission from Amazon if you click through and make a purchase.

1 Comment

  1. Pond Sealer on June 12, 2024 at 6:13 am

    Good pond leak repair blog. I’m repairing my pond too, but the only difference with your plan is I’m going with Pond Pro 2000,it’smy go-to. After being applied, it can go below-freezing temperatures at night. It’s UV-resistant, puncture-resistant, and non-toxic, so it’s 100% safe for fish, plants, and other aquatic life within the pond.

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