Flexible Water Tank - Leaky Connection

[Slipperman]

I have a Plastimo flexible water tank which has just started leaking for the first time in 6 years. I suspect, but have not yet totally proved, that the leak is coming from the outlet connection on the underside of the tank which was not particularly tight. The connection has a fairly shallow plastic thread - can I use PTFE type on this to improve the seal, or would it be better to use some form of marine sealant? (Am a bit worried about anything which might attack the plastic). Any advice appreciated.

 

[Spyro]

I have a Plastimo flexible water tank which has just started leaking for the first time in 6 years. I suspect, but have not yet totally proved, that the leak is coming from the outlet connection on the underside of the tank which was not particularly tight. The connection has a fairly shallow plastic thread - can I use PTFE type on this to improve the seal, or would it be better to use some form of marine sealant? (Am a bit worried about anything which might attack the plastic). Any advice appreciated.

I don't think ptfe on the thread will help as the sealing is done by a rubber O ring between tw mating surfaces. Mine started leaking a few years ago after a very cold winter I suspect there was some water left in it. The two mating faces that are sealed by the o-ring became slightly distorted. I solved the problem by fitting a thicker o-ring.

 

[millbeach]

The thread to the bag should not get any water in it.
The o ring does the sealing, maybe you have a damaged o ring?.
Yes change the ring, but make sure you tighten it up hard, and do not crimp the ring..

 

[maby]

... and, given the reports that Plastimo are about to go belly up - do it quickly!

 

[davidpbo]

I have had problems with these bags.

If the bags and are sound as others have said it is likely to be the O rings. I got new ones from an engineering suppliers but they do hydraulic hoses etc.

You may be able to from a plumbers merchant.

Make sure they are seated right when you fit them.

 

[wiggy]

I always used self amalgamating tape to add a layer of protection against leaks. Really expensive from swindlery but cheap as chips from here http://www.qvsdirect.com/

 

[chasroberts]

I always used self amalgamating tape to add a layer of protection against leaks. Really expensive from swindlery but cheap as chips from here http://www.qvsdirect.com/

Great link Wiggy. That really is very cheap considering I was forced to pay 12€ for 5mts of 'emergency tape' at a local swindlery. Might get a couple of rolls just in case....

Chas

 

[Paragon]

Force 4 I think were doing a special recently on the inner bags for these, they also do new fittings kit which includes both ends. I bought one of each so that I'm covered for some years to come and it was substantially cheaper than a complete bag.

Hope this may prove useful.

 

[Slipperman]

Many thanks for all replies - very helpful. I will certainly look for the fittings kit.

 

[Spyro]

Every size of o-rings available here
http://simplybearings.co.uk/shop/o_rings.php

 

[VicS]

Many thanks for all replies - very helpful. I will certainly look for the fittings kit.

Just a thought.
Are you supporting the tank so that there is no strain or pressure on the outlet fitting, or is it scrunched up underneath with the weight of the tank on top of it.

Mine is a triangular pillow tank, purpose made, not a Plastimo one,. Both the inlet and outlet are on the top.
I forget when I bought it .. but at least 30 years ago and still going with no leakage problems

 

[Slipperman]

The tank is a bit squashed up, with the take off on the underside - the tank is rectangular but the compartment is wedge shaped with a triangular cross section and a couple of ribs intruding! So not ideal, on the other hand it has worked well for the last 6 years! There is actually a more suitable locker further aft under a double bunk, but this will mean re-routing the various hoses, which in turn means more holes in bulkheads etc. Might think about it I get further problems however - maybe next winter!