Haven't been able to make much difference. I did read that acid chemicals shouldn't be used.
First off:
I used 'Blue Bullet' a car headlight cleaner - not much difference
Then I used toothpaste, hardly noticeable
Brasso cleaner, hardly noticeable
Bar Keepers friend made into a paste, maybe I could see a difference
Anti Cal bathroom spray - meahhh ?
Somewhere in the 'process' I used WD40 several times.
The stains do feel rough, like there's calcium.
The other side of the boat is fine. Though this side is where the chimney is, so maybe there's been an acid reaction, possibly when the chimney was smoking and it was raining.
Wondering if anyone has more ideas I could try? Thanks.
Before.....
After.....