RTV Silicone Sealant

[alan_fincher]

I've had many recommendations to use RTV (Room Temperature Vulcanising) Silicone Sealant.

 

But ringing miltiple DIY Suppliers / Hardware Supplies / Builders Merchants has drawn a total blank. "Yes, they stock silicone sealants", "No, They have never heard of RTV".

 

Best I found was somewhere that could order it in, but minimum order to them avout £750 worth (!)

 

I can't even seem to find a mail order supplier.

 

Any ideas, please ?

 

Does anyone have brand names, which maybe, just maybe, might mean more to someone than RTV ?

 

How much less good is it to use just any Silicone Sealant? It was suggested to me that it must be "Neutral Cure", because "Acetic cure", (I think) could damage the window frames. Does that make sense, please, and how do I know what I've bought ?

[Moley]

Well correct me if I've ballsed-up, but I've used regular exterior grade silicone sealants from B&Q, around 3 to 4 quid a tube.

 

If it says it's for exterior use, wood, metal or plastics, and has some flexibility, then what's the difference?

 

It's not like I'm ever going to take our boat into a marine environment.

 

Ade.

[ChrisPy]

I think we've got an RHT here. Red Herring Thread. If silicone goes off at room temperature then presumably that classifies it as RTV. And all the silicones you buy at the DIY store will be like that.

[Richard Bustens]

What are you trying to stick with it Alan

[alan_fincher]

What are you trying to stick with it Alan

I'm about to rebed a leaking window. So anodised aluminium bedding on to steel, (hopefully painted steel, if I can actually get any to dry at current temperatures!...). Window held by screws passing through holes in cabin side into wood battens behind.

 

Maybe it is a Red Herring, but both John and Daniel have suggested that RTV is best. I can see it's made, find places that will sell me £750 worth (!), but nobody seems to want to sell me a couple of tubes.

 

I can by a normal Silicone sealant that is "one part neutral curing low modulus" from a local window suppliers (at only £2 per cartridge). I've used some of that on a temporary job today. It was quite runny, and showed little sign of going off some trime after I had applied it. Not really convinced its going to be what I need under the window, but it might be OK.

 

An alternative, at my chandlery would be something called Sikaflex 291 - it's not a silicone - it's polyurethane based. It would seem OK although it doesn't mention windows, but says it should not be applied under 10 degrees C, and it's never that warm here, at the moment....

[DHutch]

It may well be a redherring, all i know is that in our local DIY shop they stock sealent which calls itself RTV silicon, which advertises itself external use.

- And is 50p more than the std "contains silicon" bathroom and frame sealents they stock.

- And was recomend by the guy at the till and being better than the others (which basical arnt silicon at all)

 

So maybe most silicon sealents are the same, and equally good?

- Obvouly the whole "contains Silicon" is a bit omunous!!

 

They also stock a polyurethene sealent (not sikaflex), which can be painted over.

 

 

Daniel

[Amicus]

Not sure this helps

http://www.techsil.co.uk/GE-C-5-Pro-si-gen.html

[DHutch]

Not sure this helps

http://www.techsil.co.uk/GE-C-5-Pro-si-gen.html

So basicaly its all RTV, if its silicon at all.

[Richard Bustens]

Well i used the stuff from B&Q 6 tubes in a pack for £15 i have used it for sticking in windows sealing roof vents and putting on tiles and im'e pretty sure they wont be coming off.

 

Also when i seal windows i put a bead on the surface and let it go off to make a flexable gasket so when you fit the frame it compreses the bead to make a good tight seal, then just a tiny bit on top when fitting just to make a sticky seal.