Silicon around shower tray not bonding

[goooba769]

Recently fitted a shower tray and I have sealed all the way round with silicon for use in bathrooms but the stuff just does not want to stay bonded to the shower tray in some places!!
Has anyone any ideas?
Was thinking of spending more money on a named brand of silicon but it might just be the shinney/smooth surface its finding difficult to bond to.
Was also thinking of trying to rough the surface up with sand paper but not sure?

Anyone have any ideas as Im getting water down the side which cant be helping the floor under it!

 

[gregers]

i think your going to have to remove the silicone and let it dry out completely silicone has trouble sticking to damp services.

 

[TicklyT]

The tray may still have some remnants of the release agent used to help remove the tray from the mould in the factory. IIRC this can often be cleaned off with a drop of methylated spirits

 

[gcol]

Yep, meths is the answer.

 

[Bilioustrumpstaine]

A good brand of silicone won't hurt either.

http://www.choiceful.com/choiceful-id-81-Dow-Corning-785-White-Sanitary-Silicone-Sealant-310ml.html