how to seal a hot water tank

[billi]

I have 2 180 l integrated  solar-panel water heater  (18 tubes 47 mm  1500 mm long)

The tubes are not filled with water , the standard tube that  passes on the heat 

One is fine , but the other i had to disconnect   cause leaking 

The "fins" are pushed into the tank through a silicon seal

I am feed up with trying to  find or repair the leak


So is there a liquid  that seals, that i can poor in the 180l tank and seals and health friendly    ?

Billi

[knighty]

would something like radweld work ?

normally, when your car has a water leak, you pour it into the radiator (when cold) and then let the car idol for 20 min so it warms up slow

the rad weld mixes with the water... and leaks out of the leak.... but when it's hot... and mixes with air (at the leak) it sets hard... and seals up the leak


it sounds rubbish.... but it works surprisingly well !

[billi]

hey knighty   a good thought ,  and one of my ideas as well .... but do not expect it is the right material for my son having a bath with , but do not know 

[guydewdney]

Try "jet blue" - which isn't blue.... Its safe for 'potable' (ie drinking) water. Its a paste - about £10 per tub. It seals anything (hydraulic, water, air etc)

Alternativly, try an araldite / epoxy resin - but this fails at 70 degrees C

[matt_w]

Sounds a tricky thing to fix as I would expect these additives may not adhere to silicone very well especially as the silicone can move, you could try some heating system sealant
http://www.screwfix.com/prods/45902/Plumbing/Central-Heating-Treatment/Fernox-Heating-Leak-Sealer-Concentrate-500ml

I don't know how your system works exactly but sounds like heat pipes go through a silicone seal, how about decommisioning and cleaning up the silicone seals, ideally replace them if possible but if not, use a high quality silicone adhesive around any parts that overlap to try to form a seal.  It could be a bit of a one way journey though and you may never seperate them again!

[billi]

I will have a look at these products ....

To get these silicon o - rings in and out , will be  some job     

I assume the whole panel leaks more now cause was not filled with water  and too much heat generated at the seals ( i guess)

Billi

[matt_w]

In those photos it looks like the heat pipe bits have got corroded - that could perhaps lead to an imperfect seal - probably just my eyes though!  I'm surprised Silicone would suffer from heat, we use silicone oven gloves, baking trays, oh and as exhaust pipe sealer!  Silicone should be good for over 200 degrees centrigrade.  I'd definately attempt seal replacement if it is humanly possible though - are they available as spares?

[billi]

 they are available and my supplier would post ....

I thought as well silicon will easy handle temps to a bid or more over 200°

You are right our water is corrosive   (iron /manganese ) and i am still working on a plan to solve this ....
Like said the other (same) panel is fine

I guess (rude Billi  ) my plan is to angle the leaking panel for a while in such angle that the tubes are at the bottom ( now they  are sticking into the tank about 100 mm  higher then the bottom of the store

And then fill A material through the half inch water inlet in   

or save the tubes and built a manifold for them to add extra heat for the remaining 180l tank panel

Billi

[guydewdney]

there is silicone, and there is silicone. Cheap bathroom silicone sealant is NOT the same as the sealant for heat....