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i recently dug out an old pond in the garden that had been filled in as a flower bed by previous owners. Its a plastic liner but has had 4 or 5 holes punctured in the bottom that look repairable. (they are about 3-4cm diameter).
Problem is i cant get the liner completely dry as water is entering the liner through these holes (water table must be above the pond bottom). If i can seal these holes temporarily then i can dry the liner and put a proper repair over the base.
Is there any cement or filler that can be used underwater? Does expanding foam set underwater??
how big are the holes?
3-4cm diameter
theres about 10cm depth of water in the pond that i need to work under
and how deep does the water fill to if you let it seep in? And how fast? are you sloshing around or is it a slow dampening..?
Just put a new liner over the old one?
a new liner wouldn;t be that expensive as you coudl run somethign fairly thin over the existing liner and not worry about punctures from sharp stones etc?
fills reasonably fast, definatley not just a slow dampening.
I did think of a new liner, but the pond is fed from a stream, and the outflow back into the stream is 2 plastic drainpipes set into the existing plastic liner about 5cm from the top, so if i put a new liner in i'd have to somehow seal it around the top edge and around the drain pipes or water will get between the new liner and the old one which might cause the new liner to bulge / fold inwards?
the existing pond is a preformed rigid plastic job.
ERK stuff here?
http://www.koicarp.net/pond_construction/sealants_adhesives.html
some polyurethane type adhesives are encouraged to set by moisture. Those cans of expanding foam for instance, and gorilla glue (or cheaper own brand alternatives). Best though is probably "Sticks Like Shit" similar to No More Nails, but a different formulation. I've used it for water proofing sound sculptures on a scottish mountain side.
Erm........you want a pond and you've got a hole in the ground that keeps filling up?
or water will get between the new liner and the old one which might cause the new liner to bulge / fold inwards?
As you've got water coming in through holes in the old liner I can't see what the problem is? Won't the water that's [obviously] there cause the existing liner to bulge/fold?
Edit: Actually could you just glue a much smaller liner on top of the existing one. This way you could cover the holes but still is the existing outflow pipes.
TooTall - yeah but if i fill the pond to the top, it then drains out the holes until the level is same as the current water table level!
Underwater concrete is available, but it ain't cheap and it's bloody hard work to mix (very sticky, glue like, consistency).You'd probably have to buy a 10kg bag minimum. Shovelling it underwater ain't much fun either 😀 .
+1 for expanding foam. I used it on my garage roof where there were several large holes. I applied it during a heavy rain shower ( I was literally pushing the nozzle into 3" of water) and it set like stone.
You might want to wait a while if you're hoping to introduce fish to the pond as I understand it's pretty toxic.
Re fibreglass it,buy the sheets and the resin and redo the bottom and sides, this seems like OTT but the only way you know it is sealed properly, paint with aqua friendly paint job done
Here's a linky to a much bigger pond Lined with the stuff I'm on about
http://www.koicymru.co.uk/fibreglass.htm
Cheers Matt
-1 for expanding foam. Its normally open cell so is not water tight, and its not UV stable unless painted. Plus, it could taint the water and kill the fish.
You could try expanding foam and then slice it off until its below the level of the liner (leaving a plug) and then concrete over.
I love these posts!! Shovelling under water concrete 😆
Sika do varying products that will produce very fast setting mortar. Two versions, pre mixed 10?kg bags which you add water to or 5 litre tubs which you add to cement. Personally I prefer the liquid. Small amount of liquid in tub pour in cement mix like **** slap it on with gloved hand. Seemples!!
That shovelling was bloody hard! Bloody stuff sticks like glue to the shovel, then peels off in strands as you're tying to get in into the anchor block or whatever. Beats working for a living...
😀
Is there any cement or filler that can be used underwater? Does expanding foam set underwater??
Cement sets under water you just have to add 10% more to cope with seperation(ex-army diver/commercial diver).
Expanding foam floats so not really good in any depth but you may get away with it if you squirt it into the hole.
There's loads of rapidly curing fillers that are available from yaught suppliers but these are pretty expensive (sika flex).
Shovelling under water concrete
You may laugh.
thanks for the replys,
Found some underwater cement from polycell -
http://www.polycell.co.uk/products/polycell_quick_set_cement_polyfilla.jsp
and its only £5 ish, so i'm going to get some pea gravel, pour that into the hole to fill any larger voids then cement over the top.
If that doesnt work i think i'll try the ERK silicone stuff that stoner recommends. Once hole is sealed and i can dry the pond i'll fibreglass over the cement plug like matzzz said.
Ed make sure you have everything in place and ready because it really does cure that quickly! Also can you not leave a little puddle pump running in the bottom of the liner just to keep the volume of water down??
If you are just looking to plug the holes as a temporary fix to allow the water to drain out could you not use something like a balloons?
If there is some space on the outside of the liner that it could be inflated into as long as it stays larger than the hole the water pressure from the rising water table should keep it in place.