I AM TRYING TO REMOVE PAINT FROM MY EXTERIOR DOOR SURROUND. ITS A 1930'S SEMI THAT HASNT BEEN TOUCHED FOR DECADES AND AROUND THE FRONT DOOR ARE A SERIES OF SANDSTONE SORT OF 'COPING' STONES. IVE USED STANDARD PAINT REMOVER AND IT IS JUST A NIGHTMARE OF ENDLESS LAYERS OF PAINT ! I HAVENT ACTUALLY MAN...