Working as a trade plater for two and a half years was quite tough too. A 70-hour week was a short one but, with the job only paying around 40% of the National Minimum Wage (as I was technically self-employed), it was necessary to work really long hours in order to make any money.
My longest working day was twenty three and a half hours long, from 0130 to 0100 the next day but, because I'd had to fork out so much in travel expenses to get between jobs, I still didn't make much money from it.
My worst-paid day though was twenty hours long. When I calculated what I'd earned after paying all of my expenses for that day, the figure came to just one pound (before tax!).