Help it leaks: new fiberglass

[paul chubb]

Hi,
tearing my hair out here. I have a small plywood based pond. I have tried all sorts of things to seal it: pondliner is ridiculous because the pond is too small to fold and cube in shape. Waterproofing membranes that claim to work but down and finally fiberglass.

This is a single layer of chopped mat with polyester resin over it. I did two coats of resin waited over a week and then started to fill and it leaked. I dried it out and scuffed the surface with sand paper, cleaned it and painted another coat. Waited a week and filled. Same problem it leaks.

I must be missing something. Am I not putting a thick enough coat when I brush it on or do I need to add more coats or do I need to do some form of top coat?

Any help gratefully received.

Cheers Paul

 

[Usman]

hi welcome , i dont have experience with fiberglass but some times leaks can b stuburn , i had one old type aquarium made of coaltar and i did everything possible but it would leak again , in the end i threw it . i would suggest if u have tried everything , add some kind of liner or plastic inside and glue it to fiberglass . or apply waterproofing rubber paint .

 

[AJ1500]

having some exp working with fiberglass I can tell you unless your doing the entire pond this will most likely not work. when laying glass you have to roll or sqeegee out the air from the glass, just painting the resin on won't seal it as it will be full of tiny air bubbles. also the fiberglass may not be completely bonding to the other material
give some more details or better yet take a couple pictures and someone here can offer a solution that will work
how big is your pond and is it square or round, when you say too small for liner how small, they sell small liners at Lowes and Home Depot

 

[paul chubb]

hi welcome , i dont have experience with fiberglass but some times leaks can b stuburn , i had one old type aquarium made of coaltar and i did everything possible but it would leak again , in the end i threw it . i would suggest if u have tried everything , add some kind of liner or plastic inside and glue it to fiberglass . or apply waterproofing rubber paint .

Thanks Usman. I have tried a couple of different sheet plastic style liners and the pond is too small for them to work well. I have also tried paintable membrane which also didn't work.

 

[paul chubb]

having some exp working with fiberglass I can tell you unless your doing the entire pond this will most likely not work. when laying glass you have to roll or sqeegee out the air from the glass, just painting the resin on won't seal it as it will be full of tiny air bubbles. also the fiberglass may not be completely bonding to the other material
give some more details or better yet take a couple pictures and someone here can offer a solution that will work
how big is your pond and is it square or round, when you say too small for liner how small, they sell small liners at Lowes and Home Depot

Hi AJ1500, This is a new installation and the complete pond was fiberglassed. I thought I knew what I was doing and had reviewed various how tos on the net. To avoid the issue with bonding, the fiberglass was to form a liner supported by the timber surround.

I have attached a picture

While saturating the mat with resin, I used a purpose fibreglass roller after applying the resin with a dabbing motion by brush.

Cheers Paul

 

[Meyer Jordan]

Interesting. What is the black pipe-like thing coming vertically off of the horizontal plumbing. In the photo it appears to also penetrate the bottom. Is this so?

 

[paul chubb]

Hi Meyer,
the horizontal pipe goes to water two pot plants and to also empty the pond outside. The protusion down into the pond is a small electric pump and filter. There is nothing that pierces the pond liner below the top edge. The high water level is below the piercings for the float valve and the fountain outlet. The float valve is the same as from a toilet cistern and is white in the picture. The pond outlet is the black pipe coming through the wall just in front of the float valve.

Thanks for your help

Paul

 

[Meyer Jordan]

You haven't indicated how much water you are losing a day. Could it possibly 'siphoning'?

 

[paul chubb]

Good point Meyer,
it is not siphoning because the water comes out in a different place. I know it is leaking because the water appears on the ground beside the pond. It is not a fast leak and I haven't managed to locate any small holes.

Cheers Paul

 

[AJ1500]

from looking at your pictures there I think your issue is it's bleeding through, ie not thick enough to be watertight
how many layers of glass is that, sounds like you are appying it correctly, here's a hint the entire surface should look as if your looking through a piece of glass, dirty glass maybe but it has to be smooth and shiny. I would say the left floor at the wall is going to be the most likely area of your leak problem,
add one more layer of glass, make sure you grind the area down along the left wall on the bottom first
once the new layer has cured 2 hours, mix your resin and paint a coat on the floor,no glass mat just resin let it cure 2 hours, flip it onto one side repeat steps of painting just resin let cure, flip to next side and continue untill all 4 sides are done,that should seal it up completely


I have to ask, being that small why not just buy a plastic container to fit down inside the box you have there

 

[Usman]

actually its very small , any type of plastic or plastic bag will do the job , there is one transparent table plastic , u can use that , its complicated what ur doing giving ur self headache for very small volume . or u can buy a container of this size easily i agree with AJ1500

 

[paul chubb]

thanks guys. A couple of reasons for not doing the container were one there is a waterfall at the back and i wanted a seamless wall to avoid leaks - hur hur. Second we couldn't find a container the right size.

I will add another layer of glass and see what happens. I will report back - probably a couple of weeks.

Cheers Paul