I checked the HE coils today for the first time since they were immersed in water in the HE bath on the 07/05, 4 days ago.
A few rust spots have shown up, so I've drained the HE vessel and removed the coil. I thought I'd get away with a fine scouring of the surface but it would appear some of the rust marks are due to imperfections in the steel which are impossible to remove with light scouring. I'll try to grind them out with my dremmel when I have time, and I'll take it from there. Pics will follow.
I've also looked at the perspex lid of the old HE vessel, and it has definately warped and clouded, with age and heat.
The life span of the new HE vessel may be short lived.