Is their a cleaning solution available containing hydrochloric acid for getting rust off paving slabs?
If you go to a DIY shed you’ll probably find their “patio cleaner” contains hydrochloric acid; however, before you go over the top it would be worth trying to soak the stains in white vinegar and setting to with a scrubbing brush. Worked for us, anyway, in removing rust from where a cast iron bench sat for years.
Try household vinegar first. It’s non-toxic and won’t harm the environment. If that won’t work you can buy muriatic acid at pool supply and hardware stores (garden dept.). That is hydrochloric. Be very careful with the acid. It’s mean stuff! Unless you want white spots where you place the acid you’ll have to water it down some. ALWAYS pour acid into water, not water into acid. Use eye protection, a mask that protects against vapors, and rubber or vinyl gloves. Flush the area thoroughly with water when you are through…lots of water.
