polythene water tank leak

[brightspark]

any sugestions on a repair patch on a cold water tank that has a small split in it .it can only be got at from in the tank as theres bracing ribs on the outside

 

[cumbriasteve]

Have done a repair on a large polythene float by running a hot soldering iron along the split, worked well and as far as I know still in place 10 years later.

 

[Paul.]

P/e can be welded with a hot air welding tool, for a one of job though you may be better off finding a local plastics fabricator to do it for you,

 

[brightspark]

Have done a repair on a large polythene float by running a hot soldering iron along the split, worked well and as far as I know still in place 10 years later.

its a big tank in a roof and a new one cant be fitted without cutting a beam awayand part of the ceiling for access and the ceilings high wouldnt dare risk melting it with heat

 

[Jim_gsxr1000]

Where is the crack, is it in the corner or the middle, if its in the middle of a section you could cut a 50mm hole removing the crack and then fir a flanged plug and nut with some silicone on the plug for security, of course this is presuming the crack is under 50mm and where it can be drilled with a hole saw

 

[PTvor]

Have a look on the tank and there's probably an imprint saying what sort of plastic it is. I'd guess it's HDPE, high density polyethylene. Then do a search on the WWW for HDPE glues (or for whatever kind of plastic it's made of). I don't think there are any which work very well bonding HDPE to HDPE, I don't know about bonding HDPE to other plastics, as in a patch.

The recommended way is plastic welding for HDPE.

If it has split, I'd wonder about the general state of it.

If it's a big tank in a roof and you can't get a replacement up there, what about two or three smaller ones and plumb them together?

 

[mike os]

is it yours or a job?...personally I would want it out

 

[brightspark]

is it yours or a job?...personally I would want it out

its at a hairdressers shop i was just asked to go look where the water was coming from through the ceiling. its only a small hatch and everyone was 2 fat to get up and look its a verry small split but on a ridge with aluminium rails on the outer edge to keep it rigid il pass on trying to fix it as the tank will have to be drained . thanks for the advice though

 

[mike os]

needs replacing imo... not worth the risk

 

[PTvor]

il pass on trying to fix it as the tank will have to be drained .

Definitely a job to dodge if you haven't absolutely got to do it yourself.

 

[gordon stephenson]

How about a temporary repair with the good old denso tape!!

 

[brightspark]

How about a temporary repair with the good old denso tape!!

well worth a try it sticks like sh ,../t to a blanket

 

[mike 109444]

Not sure what "Denso" tape is but you could try some ally foil tape from the in side, that way the water pressing against it will help it seal. I find it works well at work even in watery areas. Double up to increase thickness.

 

[Rudi McAnichal]

What about a tank liner? A flexible bag, made from butyl rubber or various plastics, that you can easily take up into the roof space. Well known technology, various suppliers, one that comes to mind is Butyl Products Ltd. I’ve no personal experience, and no idea of prices, but somebody on the forum will probably know.

 

[the snooper]

its a big tank in a roof and a new one cant be fitted without cutting a beam away and part of the ceiling for access and the ceilings high wouldnt dare risk melting it with heat

fit a new smaller tank or if more capacity needed 2 or 3

 

[wyn]

Would you also need to be careful on what is used for repairs if it's potable water.

 

[CompoSimmonite]

Haridressing salon = business premises so do it right , do it once - fit new tank. You can always fit two or more smaller tanks linked together. Screwfix list a coffin tank that will fit through loft hatches -
http://www.screwfix.com/c/heating-plumbing/cold-water-tanks/cat830964

Paul h

 

[DuffyBB]

I would have though another consideration would be is does it supply drinking water, or is it maybe just for hairwashing stations etc? Might limit what sort of adhesives/material that can be used.

 

[KemppiFrog]

My first thought after the replacement problem, would be to line it with GRP. A quick layer of glass mat/polyester resin would add strength and seal it for good.

 

[J_K]

All PE's are what they call Low surface energy plastics.
And are a complete bitch to glue.
3m do a product called DP8005. I pay £18+vat a tube for it and you need a £40 gun to use it. BUT. It does work for glueing PE's and other low surface energy plastics.
I specifically use it for glueing ABS rings on the bottom of PE drums.
And it is a structural adhesive.
In destruction testing, the PE actually fractured under the glue and the ABS ring came away with random bits of PE stuck to it.