how do you get minor mildew stains out of sails?

[iSailor]

I brought the main sail home for the winter and it has minor mildew stains on maybe 1% of the sail (had the sail professionally cleaned last winter). I tried using dish soap and a brush but that did not work.

Any advice on what to use that will not harm the sail? Factory Catalina 310 sail.

thanks,
Matt

 

[Chris Patterson]

Oxyclean. Rinse well.

 

[RichH]

If the sail is WOVEN dacron, not 'laminate' , not NYLON (spinnakers, etc.) ....

Spritz on a diluted 'caustic' detergent and let soak, soaking time is important. This will DISSOLVE the mildew/fungal cells (typically 'artillery fungus' common in the deciduous forests and woodlansd of the east coast). You may have to repeat / soak to fully dissolve the cells.
Examples of 'caustic' detergents: Tuff-eNuff (boat chandleries on the Ches Bay usually have it), TriSodiumPhosphate - TSP (paint store stuff), Lye Soap (Farm supply, etc.), etc.

Then, THOROUGHLY rinse to remove ALL the 'detergent'; followed by bleaching with an 'oxidizing agent' to remove the remaining 'shadows' and any tannins that have accumulated on the sail material. The 'choice' bleaching agent for woven dacron is oxalic acid ... either found in crystal form in paint stores ('wood bleach') or in many 'cleansers' such as Zud, Barkeepers Friend, FSO, etc.

The Ches. Bay water is 'loaded' with tannins due to the extensive drainage area that is 'forested' in PA and NY 'headwaters' of the bay. Oxalic will also remove the 'brown moustache' and 'waterline brown' ... and it bleaches 'almost instantaneously' when applied.

 

[Winkfish]

I've used X-14 on mildew before, and it works great. Spray it on, let it sit for a couple of minutes, rinse it off. As for using it on sails, I'll defer to Rich H on that.