soldering a hwc ; is it practical?

[gmartine]

Instead of pushing the nut up against the tank and trying to seal around that I'm thinking you have to do the opposite...

As I suggested in my first reply pull and keep the nut away from the cylinder skin and pack the gap with whatever sealant, tape or epoxy you're going to try, I'd leave trying an epoxy till last as it'll be impossible to remove.

How big is the gap, the thickness of the perished rubber washer so 2-3 mm or so?

 

[Ben-gee]

I’m with gmartine, you’re going about it the wrong way.
There will be a sealing washer on the inside, you need to pull this against the cylinder. I would try pulling the thing out as far as you can and knock a couple of wedged shims between the nut and the cylinder wall.
This should in fact be all you need to do, however you could then fill the gap etc with JB if it proved insufficient.

 

[gmartine]

@ Ben-gee, the sealing washer on the other side has probably perished too.

 

[hgee1205]

Thanks for suggestions

Been reading all this ; fitted at least 20 years ago so am I right that on the inside you fit a split copper washer followed by a fibre washer?
Gmartine may be right ; when I cleared out the perished outer washer I could see a light yellow white deposit around the hole on the inside?
I could not turn the nut at all with a decent spanner so frightened to do damage
I bet modern Essex flange uses decent rubber washers! Bugger

Just wonder if I'm back to the soldering plan after cleaning the gap out again , tightening the joint against the tank with maybe a wrap round ratchet strap
Could I use a mini flame torch and practice on some pipe beforehand?
solder will run into the gap and find its way into the joint I guess

Would a plumber come round to do it for me if I'm not comfortable to do it myself?

 

[gmartine]

I don't think you're grasping our suggestion.

Pull the seized nut back away from the cylinder and fill the gap with sealant and or tape behind it and the cylinder wall.

 

[hgee1205]

I don't think you're grasping our suggestion.

Pull the seized nut back away from the cylinder and fill the gap with sealant and or tape behind it and the cylinder wall.

View attachment 75636

Hi Gmartine
Yes I can promise you I get it!
It is what I have been doing from the start ; first using ptfe tape in the 2mm gap with the old washer removed and winding tight in the gap a thousand times which resulted in a slow constant leak which got worse over time.
I tried smearing LS-X around the outside which helped a bit but eventually the water burst through the silicone bigtime
Second time I have used Loktite 55 instead with Aqua Epoxy Putty on the outside as shown.This has given the best result with about 2 eggcups a day so far which I wick away but I wonder if it will get worse or better over time?
I can tell you that when I was cleaning the joint I found that I could pull out the big nut out quite a lot from the tank , maybe a cm! So I wonder if trying to pack such a large gap is not possible and so I pushed it back in to 2mm when wound the tape around followed by putty to try to lock it in place
I wish I had thought to use a strap to push the nut tighter so that the putty might seal it better (too late now)

 

[Chuck]

I suspect that whoever originally installed the flanges used some oil-based grease (e.g. vaseline) and the rubber seals have perished as a result. You're lucky you haven't had a flood!

Whatever, I suggest that you get a professional plumber to sort it out for you properly. They might be able to replace Essex flange (by removing the immersion heater for access) but it depends a bit on why the seal failed and how much damage subsequent attempts to bodge it have done. Also, cleaning off vaseline (or whatever) from the inside so the same thing doesn't happen again will be a bit of a game. If I'm right it's possible that all the flanges need attention. I'd be recommending a new cylinder myself.

While they're at it the cable needs replacing and installing properly with the strain relief and insulation done properly.

When you try to sell the flat any competent surveyor will spot evidence of leaking and an amateur attempt at a fix. If so, they'll reduce their valuation by far more than it'll cost you to get the cylinder replaced at this point.

 

[gmartine]

Chuck is almost always a sensible voice of reason, I'd just like you to get it done by almost any means so often I'm not. Perhaps as a final throw try an all weather sealant that'll work in the wet (I'd still drain down past the flange) and get an insulation jacket to cover up your workings.

Edit: Actually I like Puraflex 40 when I want to stick and waterproof anything to anything, fairly confident it'll work for you but it's tough to work with when cold so warm it up in a bucket of very hot water.

Puraflex 40 PU Sealant & Adhesive

Noticing cracks or expansion in concrete? Purafelex 40 PU sealant will help you fix it quickly. It's a useful tool to have in any construction site or home, as it bonds to most materials. This product will work on concrete, wood, metal, aluminium, polyester, glass, uPVC, stone and ceramic.Thanks...

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[hgee1205]

Chuck is almost always a sensible voice of reason, I'd just like you to get it done by almost any means so often I'm not. Perhaps as a final throw try an all weather sealant that'll work in the wet (I'd still drain down past the flange) and get an insulation jacket to cover up your workings.

Edit: Actually I like Puraflex 40 when I want to stick and waterproof anything to anything, fairly confident it'll work for you but it's tough to work with when cold so warm it up in a bucket of very hot water.

Puraflex 40 PU Sealant & Adhesive

Noticing cracks or expansion in concrete? Purafelex 40 PU sealant will help you fix it quickly. It's a useful tool to have in any construction site or home, as it bonds to most materials. This product will work on concrete, wood, metal, aluminium, polyester, glass, uPVC, stone and ceramic.Thanks...

www.toolstation.com

Hi Gmartine
thanks for the idea ; there is only an eggcup a day leaking and just oozing out so your product may do the trick.I will give it a go
cheers