Can I just add a note of caution to Tony's note that concentrated caustic soda is really nasty stuff as well as the sulphuric acid. If you get a splash of conc caustic soda in your eye, don't bother to rush to the tap - by the time you get there it will have already gone !!!!!!!
Have fun but BE CAREFUL and wear appropriate protective gloves AND GOGGLES Mike [EMAIL PROTECTED] 53.37N 3.02W Chester, UK
