Black oily stain on door that was sent of for paint stripping

[iwilson16]

I sent some old Victorian doors off to be stripped. One came back with a black stain that seems to be oozing some sort of oily substance.

anyone know what this is? How do I get rid of it? I ultimately want to paint the door, but can’t see how in this state.

photos here ….

Doors

• iwilson16
• 21 Jul 2023
• 3

Renovating old Victorian 4 panel doors

thanks,
ian