Gave oxalic acid a shot for flushing rust particles out of my cooling system.
OK I used 3 TB spoons of oxalic acid mixed in with distilled water after flushing the coolant out of my cooling system. Things looked great until i flushed and added the soda ash. A green/blue "film" formed on the block drain plug and a spotted film of the same color is present when looking through the radiator cap. Haven't taken the hoses off yet. Looks like a very thin layer of paint . Not a sludge or "growth".
I drained the base and right now theres fresh distilled water in the system. Any suggestions on how to proceed? I'm not a chemist and dont pretend to be. Will adding a small amount of acid back in remove the varnish created?
Goggle has revoked my IP address from over use. (kidding) It appears i created a copper something... caused by the acid+base reaction.. Not a lot on removing it though.. or if its harmful to the cooling system.