Separating fused lead coins

[nikopolis1]

Lead celtic imitations of Odesos .How to separete them?So far soaking in formic acid for a week did not help.I try to drive a needle in between -I give up ,lead is too soft and I will damaged them.I  think to try electrolysis  .Any sugestions for any other treatment?I suspect eletrolysis will strip the patina

[Ken W2]

Maybe 3 or 4 wood toothpicks used as wedges spaced around the edges, gently pushing them in a little bit at the time ?  Wood is less likely to damage the metal and using multiple leverage points might help too. Good luck.

Ken   

[Ron C2]

have you tried boiling them in water?

The issue with lead is that it both soft and has a low melting point.  Heat would eventually release them, but it would be easy to overdo it and melt the surface.  Boiling and then gentle prying with a wooden wedge is something you can try.

[nikopolis1]

Boiling sounds good to me .I will try .Thanks for the idea .I will leave electrolysis and heating like last resort