What sealant to use?

[davylock]

Hi, what sealant does everyone use to seal between the aluminium floor/panels and the chassis rails?. I'm sure someone's said that acrylic sealer damages the panels over time, so do I need to use polyurethane based sealant?.
I see fabby mentioned Sikaflex, I can get EBT for £7.14 locally from S/Fix if that does the trick. Anybody else recommend this make, thanks Dave.