Removing black stain from leather

[Noydini]

Hi there,

I’m trying to recondition a bag that has some black stains on the leather that have been caused by some sort of reaction to the corrosion of the press studs. 
 

Is it possible to remove this? Saddle soap isn’t shifting it…

[fredk]

Iron poisoning. It is indeed a reaction of iron parts on the leather

I think only oxalic acid will lessen it, but it might not remove it completely. You can usually get oxalic acid in powder form in hardware stores and some chemist will sell it to you. Sometimes its sold as 'Barkeepers Friend' (in B&Q afaik)

When replacing any iron or steel parts, replace with pure brass ones

[TonyV]

Oxalic acid is also sold as 'wood bleach'.  Used to lighten similar stains on wood.

[Handstitched]

In some cases, if oxalic acid doesn't work , its best to dye the whole  bag the same colour as the stains, if thats an option . 

HS