gonna be upgrading my van soon, and want to go with a 650 litre tank, anyone got some good ideas about securing this in the back, my current 350 ltre tank has been secured by battens screwed into van floor with a ratchet strap but have never been entirely happy with this, hopefully this next van will last me around 10 years, so want to get it right,I have a customer who is a welder who would help with this cheers for any replies john.