Remove residue from gold plating

[GoldUser]

Hey together,

I have some gold fingers from old displays. After removing the connector cables they left some glue like residue on the plating (see pictures).
I tried removing it with screwdriver and a knife but it didn't come off.
My process would be to remove the the base metals with HCL/H2O2 but I'm not sure if the acid will go under that glue.
Does someone have any experience with that?

David

 

[nickvc]

My advice try one piece in AP if that doesnt work try using a lye solution with heat but be very careful that’s nasty stuff so use hood gloves and eye protection.