water storage tank problem

[johnbisset]

hello all - my first visit to this forum - i hope someone can help
I have a cold water tank in the loft. It has two pipes coming from the base. One feeds the toilets and bath cold tap, the other, I believe, feeds the hot water cistern and boiler.
The gate (stopcock) on this hot water distribution pipe turned off, but wouldn't turn on again, so I have replaced it with a new one.
BUT there is now a tiny leak at the washer at the point where the pipe joins the base of the water tank. And I cannot get the nut loose. It seems to have been put on with some red stuff all around it...
Should I:
1. patch it up with epoxy resin? (milliput)
2. use WD40 and elbow grease to get nut off and replace washer?
3. Replace whole tank?

much appreciated any suggestions - and what is the red stuff anyway?
john

 

[oldplumber]

red stuff = a type of sealant. I presume the tank is galvanised steel ? better off replacing it if it is, with a new storage vessel that has bylaw 30 ( me thinks) kit and all the covers and insulation to give you nice clean water to your cold tap.

 

[foley]

I'd just drain down the system replace the washer and put some boss white round the new washer, Then fill the system back up and make sure there's no more leaks, Be carefull with old gate valves as the thread very easily, If it is a galvanised tank then just replace it like oldplumber said,

 

[johnbisset]

I'd just drain down the system replace the washer and put some boss white round the new washer

thanks - my worry is that the nut seems stuck fast and that i might damage the tank (which is plastic by the way) in the process - it looks weak and a bit bulgy round the coupler...

 

[WHPES]

Undo the nut, washer and tank coupling (you will need a pair of grips inside the tank or a wide flat screwdriver) and an adjustable on the outside. Clean everything off. Get a new nylon washer and reassemble. You shouldn't use Boss White as this can support bacterial growth (use Boss Green instead). BTW the red stuff will be Stag jointing paste (used for heating fittings and oil lines).

 

[foley]

I'd just drain down the system replace the washer and put some boss white round the new washer

thanks - my worry is that the nut seems stuck fast and that i might damage the tank (which is plastic by the way) in the process - it looks weak and a bit bulgy round the coupler...

Can you get the old coupling off? Then just repalce the coupling (the part that connects the pipe to the tank)

These old couplings need a bit of patience to get off without damage to the tank,

 

[WHPES]

No need to replace the coupling - just give it a clean up, fit a new washer and put back on.

 

[johnbisset]

you are all fantastically helpful!
yes i will try to get the nut off the coupling and replace the washer.
Is it possible that the 'red stuff' has damaged he tank - like i said it's not like the rest of the tank - it looks ... well ... irregular

 

[WHPES]

I assume the red stuff is just jointing paste - if so, no, if it's stuck on, you can get it off with meths or white spirit (can't remember which).

The washer should be a nylon washer and there should be two - one at either side of the tank.

The tank coupling will either have lugs on the inside to hold with grips, or will have slots inside for you to stick the tail of a footprint wrench into.

 

[REDSAW]

these chemicals can eat away the plastic/pvc tank as the tank is made of oil by products. what you need to determine is that the tank is reacting to something or just a bad mould pressing?.
either way, drain down to take of the m.i this way no floods should the tank fail and if it needs changing your half way there.

 

[fuzzy]

I'd just drain down the system replace the washer and put some boss white round the new washer, Then fill the system back up and make sure there's no more leaks, Be carefull with old gate valves as the thread very easily, If it is a galvanised tank then just replace it like oldplumber said,

you cannot use boss white on a cold water cistern

 

[WHPES]

Should be Boss Green / Water Hawk / Plumbers Blue etc

 

[stevetheplumber]

i find the neoprene washers that come with new tankcons work fine with no paste at all one neoprene washer inside and jobs a good un

 

[oldplumber]

isnt neoprene what divers and fetish folk wear? Nylon washers and no sealants works for me,

 

[fuzzy]

i find the neoprene washers that come with new tankcons work fine with no paste at all one neoprene washer inside and jobs a good un

true, shouldnt need any additional sealent, the washer alone should be fine. i do use ssealent if replacing as you cannot always trust old fittings and tanks etc. i used to use fernox sealer, comes in a small tube and worked very well

 

[WHPES]

Was at a job a couple of weeks ago and everything in sight had silicone on it, including all the compression fittings and tank fittings.

snt neoprene what divers and fetish folk wear

I guess you could always cut up your diving suit or gimp suit to make washers when you have worn it out.

 

[johnbisset]

yes the tank needs changing - replaced washer but still leak - so took whole tank out and finally i can see the hole is raggedly cut and when you push from behind all around it is cracked...
so maybe i'll start new thread - as the loft entrance is tiny.........
thanks for all your help

 

[johnbisset]

ah well so i'm changing the water tank for new now - and it says on the instructions that i have to cut hole with 27mm hole saw, and another with 29 mm hole saw. but in my set there is only 28mm or 32mm.. I can order the exact ones but will the 1mm either way really make a difference?
many thanks
john

 

[Puddle]

ah well so i'm changing the water tank for new now - and it says on the instructions that i have to cut hole with 27mm hole saw, and another with 29 mm hole saw. but in my set there is only 28mm or 32mm.. I can order the exact ones but will the 1mm either way really make a difference?
many thanks
john

Well it looks like you are going to have a 27mm on 29mm hole saws to add to your set

Do not know what tolerances they have allowed from hole to fitting ,would think 1 mm not a problem the 3mm should be ok buy you will depend on fittings,you are up sizing which is better than down sizing which could cause a strain on the tank from fitting,would imagine fitting flanges would take up this minimal slack,just make sure fitting centralised when fitted


imho

 

[stevetheplumber]

use the smaller cutter and rasp it out when you go to big go for next size up tank con and reducer
not that its ever happened to me

 

[kirkgas]

use the smaller cutter and rasp it out when you go to big go for next size up tank con and reducer
not that its ever happened to me

correct Steve, things like that NEVER happen to top plumbers like us, but we do know someone who has done such utterly stupid things and i hate it when i(i mean they) have to travel to the merchants for a new connector