An Illinois man has spent up to 10 hours every day for 11 years cleaning and fixing 1,500 paintings for 300 museums nationwide.

He's done an estimated $5 million worth of work. And he didn't get paid once.

He previously worked for The Art Institute of Chicago before starting his own conservation business in Chicago. By 2003, he had 23 employees and the company was starting to run him. So, he sold it and thought about doing conservation work for museums at a reduced price.

His wife suggested he do it for nothing and he agreed.

He says his motivation comes from his deep love of artists and their talents. And he says it's rewarding because "conservators come and go but paintings with proper preservation can live hundreds of years."

Matt Cardy, Getty Images