Re: quattro-digest V3 #1427

[Bewildered@aol.com]

The brownish residue on the inside of the expansion tank is an extraction of
oxidized copper corrosion inhibitor from the ethylene glycol antifreeze. Some
antifreeze solutions contain a relatively easily oxidized copper corrosion
inhibitor which in the presence of WaterWetter prefers to dissolve in the
Waterwetter rather than in the ethylene glycol solution. It isn't a problem
for the cooling system and it is not removing important corrosion inhibitors,
but rather the depleted (oxidized) ones.
I was given this explanation by the head of product development and chief
chemist at Red Line. I had the same problem.

Bill