Copper Pipe and Silicon Sealant

[1st ade]

Got chatting to a boat owner near Wolverton (not that the locations affects the question) and helped him fix a minor electrical problem with his CH circulation pump. Job Done - maybe.

 

The pipes for the rad's run under the floor, I assume they are well lagged or there is serious over-provision of energy as the radiators definitely get very hot. However, the holes for the pipes are oversize and a perishing cold draft comes up through them.

 

The owners response was to apply Silicon Sealant around the pipes. To me this feels wrong; silicon sealant gives off a strong smell of vinegar which is acidic. Putting an acidic gel in permanent contact with a hot copper pipe seems to be asking for the radiators to be found one day severed from the heat source and a very wet floor!

 

Any thoughts?

[NMEA]

If you mean where the tube comes through the floor then split colors are available from plumbers merchants, designed for the job. If you are going to use a sealant then a Polysulphide one is probably better.

[DHutch]

I must say i expect it would be fine. Else use an acrylic or polyurethane sealant, decorators calke even?

 

 

Daniel

[nicknorman]

Yes ordinary silicone sealant does give off acetic acid when it cures. For this reason it is absolutely banned on metal aircraft. Instead they use a different type of sealant that is ph neutral when curing. But of course it is a lot more expensive. However in the context of a copper pipe I imagine that the quantity of corrosive aside vs thickness of copper means it probably wouldn't be an issue. I think the acetic acid evaporates after a time.

[bizzard]

You could wrap some insulting tape around the pipe first.

[Guest]

You could wrap some insulting tape around the pipe first.

Good idea I would think.

[MtB]

In the world of domestic plumbing silicone is not regarded as a risky material to have in contact with copper pipes.

 

I suspect it is only acidic whilst curing, but even if not, there is no widespread experience of it damaging pipes. I've never heard of it happening having been in the business since silicone sealant was first invented and marketed!

[ditchcrawler]

What does LS-X joint sealer contain?

[alan_fincher]

What does LS-X joint sealer contain?

 

Fernox say "LS-X is a silicone paste", (Google it), which is precisely why I think a normal silicone sealant is hardly likely to be a risk to domestic or boat plumbing.

[MtB]

What does LS-X joint sealer contain?

 

It looks, smells and behaves like ordinary silicone sealant, so I suspect it is.

 

I'm sure the manufacturers would claim otherwise though!

[alan_fincher]

 

It looks, smells and behaves like ordinary silicone sealant, so I suspect it is.

 

I'm sure the manufacturers would claim otherwise though!

 

Quite a marketing coup if it is just the bog standard stuff.

 

I'm not brave enough to find out though, so even in the last week or so have again gone and paid over £1 per teaspoonful at Screwfix, in the hope it contains some additional plumbing specific magic!

[MtB]

 

Quite a marketing coup if it is just the bog standard stuff.

 

I'm not brave enough to find out though, so even in the last week or so have again gone and paid over £1 per teaspoonful at Screwfix, in the hope it contains some additional plumbing specific magic!

 

 

You must have pretty big teaspoons, given the tube contains 50ml and costs about three quid!

[alan_fincher]

 

 

You must have pretty big teaspoons, given the tube contains 50ml and costs about three quid!

 

I wish - not from Screwfix it doesn't. Current price £5.29!

Edited March 25, 2016 by alan_fincher

[MtB]

That's still only 52.9p a teaspoon....

[ditchcrawler]

That's still only 52.9p a teaspoon....

But then you only use 1 teaspoon of it and the next time you want it the rest has gone off.

[MtB]

But then you only use 1 teaspoon of it

 

 

How much are you putting on??!!!! I use it all the time and a tube lasts me about six months...

 

 

 

But then you only use 1 teaspoon of it and the next time you want it the rest has gone off.

 

 

Put the cap back on then....

[ditchcrawler]

But I may only use it once every 3-4 years or even less more, one of the two.

Edited March 25, 2016 by ditchcrawler

[1st ade]

Thanks to all who replied - by the time I walked past the chap's boat again he'd gone ahead and done it!

 

At least I'm armed ready for the "I told you so" moment.

[Joe the plumber]

Over the years I've seen no end of copper pipes that had silicon sealant on them, for example where the mains cold feed to an electric shower comes out of a tiled wall. I've never noticed any damage to the pipes when I've cleaned it off and have never given it a thought if re-sealing around the pipe.

[DHutch]

Over the years I've seen no end of copper pipes that had silicon sealant on them, for example where the mains cold feed to an electric shower comes out of a tiled wall. I've never noticed any damage to the pipes when I've cleaned it off and have never given it a thought if re-sealing around the pipe.

Same.

 

Daniel

[1st ade]

Thanks both. Seems to be me worrying about nothing.

[Ex Brummie]

While in Screwfix buying Fernox LS-x, check out the 'No Nonsense' equivalent. I use it all the time for fixing Aga lid seals. It is hard to see any difference in the two products. As Mike says, it is basically a silicone sealant, but comes temperature rated to a higher level.

[Neil Smith]

We always use silicone around copper pipes to seal up all air escape gaps before the air test on new build houses.

 

Neil

[smileypete]

While in Screwfix buying Fernox LS-x, check out the 'No Nonsense' equivalent. I use it all the time for fixing Aga lid seals. It is hard to see any difference in the two products. As Mike says, it is basically a silicone sealant, but comes temperature rated to a higher level.

Can't see a direct equivalent.

 

Wickes do one with very poor reviews, so I suspect there is more to LS-X than meets the eye...

 

http://www.wickes.co.uk/Wickes-Jointing-Compound+External-Leak-Sealer/p/116975

 

Dow/Geocel do one but it's about the same price as LS-X

[Ex Brummie]

For some reason, the product does not come up on a web search, but part no 35632 comes in at £1.50 + vat a tube at trade terms.