I have concrete window sills and lintels front and rear of my property which are in dire need of repainting, the current paint is peeling and looks shabby. Last year I had a go myself at stripping them back to the concrete but just gave up and over the years they have been painted and painted etc. i think it is time they were taken back to concrete and started again, i understand there is an acid on the market specifically for this purpose, could someone in the know please tell me where i might get it and would you also be so kind as to tell me by what method i should re-paint them, bearing in mind that i live relatively close to the sea, thank you