OK, so any one out there have additional ideas of what could cause a red stain on a cement bulkhead ? Looks like a red residue was sprinkled over the entire surface. I am thinking Red Lead Oxide or Mercury Oxide as a poison. Can't think off hand of any WW2 era pesticides that have that. Not completely water soluble since some is still remaining in the pores of the cement, but it coats every bit of the outside surface. Not paint.
Hmmmm
Z
