Laundry trough -water tank

I have been instructed to renovate the laundry.

Gazing at the dreadful task I spied our dual sink stainless steel trough and have been musing ever since about turning it into a nice water tank for the camper trailer.

Idea is to attach a lid made of something, maybe marine ply, maybe sheet plastic, and attach it under the trailer with supports or straps. In and out holes would be constructed before the lid went on. Or for a more cubic design, or double the capacity, buy a matching unit and weld them together using stainless rods in my inverter welder.

Pros
After a good clean and dis infect, it's good stainless so water won't have a plastic taste
It's about 70 litres so a good volume

Cons
Alleged fragility of stainless. Mounting with flex built in might alleviate this
Others are Over to you.

And the best thing is that a week has passed and the laundry is still intact, I have been successfully diverted onto something much more interesting!

Tim