Fresh water tank leak fixing

[UFO]

On our way back from nearly five weeks in Spain and Portugal. The fresh water tank in our 2009 Adria Twin is leaking. I won't know where the leak is from until I get home and take it out. Adria have quoted £210 for a new tank.

The tank is made of the white plastic which feels slightly greasy - don't know the proper name for this material.

The leak is slow so the crack will be small. Would appreciate advice on how this type of material can be sealed. I thought about fibre glass but I don't think it would stick. Another thought is something like Sikaflex possibly sticking an aluminium plate to the area where the crack is.

Thanks

 

[n brown]

get a tube of Stixall and see if it sticks to the plastic before you attempt the repair. Araldite can often be the answer as well, sticking a bit of ally to reinforce is a good idea once you know which glue works. if the crack is on a flat area , electrician's tape or Gorilla tape could do the job, there's very little pressure involved

 

[Deleted member 5816]

Until you look you wont know if its just a loose fitting for the drain off wait until you examin the tank to make your plans

Alf

On our way back from nearly five weeks in Spain and Portugal. The fresh water tank in our 2009 Adria Twin is leaking. I won't know where the leak is from until I get home and take it out. Adria have quoted £210 for a new tank.

The tank is made of the white plastic which feels slightly greasy - don't know the proper name for this material.

The leak is slow so the crack will be small. Would appreciate advice on how this type of material can be sealed. I thought about fibre glass but I don't think it would stick. Another thought is something like Sikaflex possibly sticking an aluminium plate to the area where the crack is.

Thanks

 

[WildThingsKev]

I had a leaking tank in my Rapido, you can read about it in the last few posts on this motorhomefacts thread: http://forums.motorhomefacts.com/63-rapido-motorhomes/112238-water-tank-leak-7090-a-2.html

The tank material will probably be polyethylene which is easily repairable, if you know how, though £210 for a new replacement doesn't sound too bad. It may well be that it's just one of the connections leaking, stress cracking from the poorly designed feet was the cause on rapidos but polyethylene is very tough and is unlikely to suffer from it.

If it is cracked, then sealing the outside with mastic/tape won't be effective, polyethylene is difficult to bond to. It will probably be quite a job to remove the tank and it would need to be welded/replaced or else you could be doing it again pretty soon.

If you find a crack it is likely to be hairline and only noticeable with close inspection using a bright light. If determined to try a sealant get Soudal Fix-All from Screwfix, we use it in the (polyethylene) canoe trade to bond in foam bulkheads. Best to lightly flame the surface first in order to oxidise it and get a better bond - if you're brave enough! (Ask for more tips first).

Kev

ps We were on our way back from France at the time and showered using 2 litre bottles of hot water (from kettle) with 6 holes drilled in the cap.

 

[spigot]

If you say the tank feels slightly greasy, the material is probably polythene, most adhesives ain't gonna stick.

I have sealed cracks before in polythene by running a soldering iron along the split.

Worth a try before buying a new tank.

 

[UFO]

Thank you for the ideas - much appreciated.

Got the tank out easily. There is crack around the drain pipe. Outside diameter of drain pipe = 28mm, internal diameter = 18mm, crack length = 35mm.

Nick from Cambridge (don't know if he is also on this forum) has done a number of Adria Twin modifications including this one Water Tank Drain http://www.motorhomefacts.com/forum-printtopic-1-136917-0-0-asc-viewresult-1.html so I will investigate doing something similar, possibly in combination with the soldering iron repair idea.


Crack from outside
Crack from inside

 

[Canalsman]

Being able to get at the crack from the inside of the tank is a bonus.

If you place a flexible patch of some kind over the crack, then the water pressure will force it into the crack. This will also help hold the patch in place.

That's the avenue I'd explore.

 

[hextal]

I don't generally like silicone sealant, but if it's fresh water is it worth gobbing it up with food-grade silicone sealant rather than the more heavy duty PU type sealants?

Any obvious clues as to why it cracked? Pipe connection pulling it etc?

 

[WildThingsKev]

Silicone will just peel off.

That is quite a big crack and needs a deep weld, ie filleting out a vee the same as welding steel plate. If I was doing it I would also weld thick "tacks" across the repair to stiffen the area. Toying around with a soldering iron won't provide a lasting repair.

It looks like the tank must be able move a bit and the long lever arm of the drain pipe has stressed the area around the crack. That movement needs to be stopped.

I think you need a professional repair or a new tank.

 

[ian81]

Silicone will just peel off.

It looks like the tank must be able move a bit and the long lever arm of the drain pipe has stressed the area around the crack. That movement needs to be stopped.
.

That movement needs fixing or it is likely to happen again. The hole in the van floor that the pipe fits into may need enlarging to allow the pipe to flex with variation in temperature and amount of water.

Never used CAK tanks but they may have a cheaper option.

If the various suggestions above fail you could try cutting the tube off and making a sandwich of two pieces of plastic on the problem area, then drill a hole for a new drain fitting.
Best wishes

 

[oldish hippy]

well cut a 2 larger circles of plastic then drill out size of drain in center the drill hole around thedge then do same in tank fit rubber gasket then bolt together through tank ok drastic measure if all else fail s



easy description large polo mints with holes drill around the thick bit bit neoprene gasketsandwich