Sealing two types of pond liner

 I have a waterfall, which flows into a small stream constructed with
rubber liner, that then flows into a small pond.

The pond liner is (I think) some kind of cheaper plastic looking liner.

I believe water is leaking where the stream liner overlaps the pond
liner, ie water is creeping back up between the two liners.

I was wondering what is the best way to make a seal. I know you can
cement rubber to rubber, but I'm not sure about rubber to plastic, I was
considering using silicone (normal bathroom silicone) as it seems to be
very sticky on both types of surfacea and I already have a coiuple of
tubes, but I wonder if this could have harmful chemicals for the fish.

Any other things I could use?

(While writing this, I just realised that aquarium sealer must be safe,
but would it be flexible enough?)

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Best regards,
Ms Fish

 On Sun, 24 Jul 2011 11:03:38 +0100, Amanda


Assuming that the "rubber" liner overlaps the pond liner and that the
pond liner is higher than the level of the pond, water should not flow
upwards back under the stream liner and you may have a leak somewhere
else - check around the pond at the level the water in it settles. I
would guess that the "rubber" liner is actually butyl (the best form
of liner as it can last up to 50 years if treated right). If the pond
liner is "cheaper" then it might be either PVC (10-15 year lifespan)
or polyethylene (3 years at most). If it's polyethylene then it would
be as well to drain the pond and replace the liner with PVC or butyl
as a first step.

I suggest that you buy a pond repair kit (or just the adhesive if sold
separately) from your local garden centre. The adhesive is made to
stick liner together.. You will need to drain the pond to below the
level of the join, and allow the area to dry. Then fold back the upper
liner and clean both faces thoroughly. Finally wipe with mentholated
spirits. Apply the waterproof adhesive to both surfaces and as soon as
it feels dry to the touch press the surfaces together and smooth
carefully to remove any air bubbles. Apply a weight to the join and
leave to fry for the amount of time specified on the tube/kit before
refilling the pond.

If, OTOH, you find another leak, it's a patch job (patch material will
be in the kit) but make sure that the patch extends at least 2 inches
all round the tear.

Cheers
Jake
==============================================
Gardening at the dry end (east) of Swansea Bay
in between reading anything by JRR Tolkien.

www.rivendell.org.uk

 On 24/07/2011 12:07, Jake wrote:

I have checked for other leaks and there are none in the pond or
waterfall, what seems to happen is that even if the rubber liner of the
stream is higher than the water level, water still wicks back up underneath.

I think it's bit like an external window sill, if it doesn't have a
groove underneath the same thing can happen, most of the water falls
straight off but quite a lot still goes back up underneath. IA house I
lived in once had huge patches of damp wall because this groove was blocked.

The problem is you can't do anything like that with rubber. It needs to
have a vertical end rather than horizontal.

Anyway I'll try the pond liner repair kit, I hadn't realised it would
work with anything other than rubber. I think it's PVC, sooner or later
I know it should be replaced but that's a big job for now as the pond
has paving round the edge.



--
Best regards,
Ms Fish

 On Sun, 24 Jul 2011 13:11:02 +0100, Amanda wrote:


<snip>

Well loop the waterfall liner back up around something so it forms an
edge for the water that flows around the end and back along the
horizontal underside can drip from.

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Cheers
Dave.

 On 24/07/2011 22:45, Dave Liquorice wrote:

That's definitely worth looking into, but will mean getting a whole new
liner for the stream as it's too short to do that at the moment.

I was hoping not to have to rebuild the stream, but it could be a very
good solution.

--
Best regards,
Ms Fish