We bought a
boat in the
Pacific Northwest (read "lots of rain") that hadn't been cleaned in over 5 years (read "lots of mildew"). It seems I worked on it constantly over the course of 3 years with no results. Last year I developed a new strategy that WORKS and after 11 months, we have 0 mildew.
I have to give credit to a
member "Zeehag" for guiding me on this - her famous quote is "Vinegar kills mildew, bleach just gives you white mildew".
1: take a brush while it's dry and vigorously brush the dried mildew off both top and bottom. (wear a mask, the mildew dust is disgusting)
2: take a spray bottle of vinegar and thoroughly spray both top and bottom with the vinegar (if you can find double strength vinegar in a
cleaning supply place, that's what I used). Walk away and let it do it's magic for an hour.
3: after an hour, respray with a combo of the vinegar and a cleaning solution (I used Simple Green) and brush into the fibers.
4. Rinse and let dry. I tried to time all this for a period with no rain in the near future.
As I say there's no mildew, no mildew stains and no return of the mildew.
(fingers are crossed for the future, believe me..)
Good luck!