wrong type of silicon?

Yes, the one with an e at the end ;-)

MBQ

Are you sure it WAS silicone ( and not some sort of decorators caulk) as silicone goes off and becomes fairly hard /flexible state. You get silicone designed for sanitary work .Not sure what any difference may be but probably has mould preventing specs. Stuart

And smells strongly of vinegar.

Regards

Mark

Are you sure it's not silicone grease that you've got? That's waterproof, so good for assembling taps, waterpumps etc. but obviously it doesn't go solid.

They are both formulated with a fungicide. The only one that isn't is aquarium grade because fish are very sucseptible to biocides. Heaven help you if the Environment Agency and DEFRA catch you after letting biocide get into a waterway. Quite a few years ago my then company was pilloried for about 100 litres of PVA into a canal. PVA is not toxic to fish, but it created a bloody great white slick leading to our wharf. HDQ.

John Schmitt

I'd use Plumber's Mait for this, not silicone. Stickier and non-setting.

Use Plumbers Mait (sp?) rather than silicone. It's like the putty that you use in windows - simply roll out a sausage of it in your hands, place round the waste hole, put the waste back in and Bob's your uncle.

Mogweed.

I know this may sound obvious, but did you wait for the silcone to go off before throwing water into the shower tray?

Sounds like heatsink compound !

Sanitary grade stuff, I suppose; and it will state that it's suitable for bathrooms etc on the packaging. It certainly isn't water-soluble, which sounds like it's the case with whatever you've used I'm afraid!

David

This sounds like it might have been acrylic bath sealant rather than silicone - absolutely dreadful stuff IME. Use plumbers "mait" round the waste and silicone around the outside of the tray.

Dave

I'm sure I've read, on the side of a tube of silicone, that lightly spraying the wet silicone with water will decrease the setting time.

How long did you leave it to cure for? It skins over fairly quickly, but takes some days to fully cure if applied in thickness, or where the air can't get at it freely.

Acetoxy cure (vinegar smell) silicone cures by the replacement of acetic acid molecules in the silicone with water. If you want it to set instantly, mix in some slightly damp cement powder. Less instant the less aggressive the alkali is - I've used bicarbonate of soda to create lightly foamed silicone set in about 5 mins.

This is correct. The silicone sealant is water-catalysed. Once the reaction is initiated each coupling of acetoxysilicone releases one molecule of acetic acid and one of water, so the reaction is self-sustaining. There is a scavenging agent in small quantities to take out the odd molecule of water to maintain stability in the tube. In the gulf one of our customers was having problems with the near zero humidity. Once we told him the trick he went away a happy man and proceeded to buy several more container loads of our products.

John Schmitt