Quite by accident, I recently discovered that an acidic super drain cleaner composed mainly of sulfuric acid cleans the FeCl3 stains on hard surfaces almost instantly. The MSDS on these products lists the sulfuric acid content at approximately 90+%. Obviously, they are not to be used on fabrics.
Baxter
--- In Homebrew_PCBs@yahoogroups.com, Leon Heller <leon355@...> wrote:
>
> Oxalic acid is about the only stuff that removes FeCl3 stains from
> clothes etc. I bought some a long time ago, but have never needed it
> until my latest PCB making exploit, when I got a couple of small
> splashes on a pair of cotton trousers.
>