Algae on sails

[C08]

My foresail having been left on the boat is bright green with algae but no mould. Strangely my inner foresail is pristine white despite being on the boat for the same period of time. What is the best way I can clean this algae off before storing it over winter?

 

[SimonKNZ]

My foresail having been left on the boat is bright green with algae but no mould. Strangely my inner foresail is pristine white despite being on the boat for the same period of time. What is the best way I can clean this algae off before storing it over winter?

I spread mine out on the driveway then applied water and laundry stain remover. Leave to soak for a while then scrub with a broom. Didn't get rid of 100% but a whole lot better than it was

 

[RobWard]

My foresail having been left on the boat is bright green with algae but no mould. Strangely my inner foresail is pristine white despite being on the boat for the same period of time. What is the best way I can clean this algae off before storing it over winter?

Wet and Forget seems to be the wonder algae killer of choice.

 

[MoodySabre]

Wet and Forget seems to be the wonder algae killer of choice.

Or Patio Magic

 

[Gwylan]

Another one for Patio Magic.

 

[Bobc]

Give it a good soaking in patio magic with a pump sprayer.

 

[C08]

Thanks - Patio Magic on order. I will do the sheets which are black, mould I think at the same time.

 

[C08]

I have mixed the PM @ 4:1 as on the directions and given the sail a light scrubbing all over with it. I note that the product info says that it can take up to 4 days to kill off algae? I have left the sail drying in the garden to see how it goes and then probably another scrubbing tomorrow. I am unsure when I have finished whether to wash off or just leave - any ideas?
Also what can I do to prevent the green creeping back?
Thanks for advice.

 

[MoodySabre]

If the green has gone then just leave it. It will continue to be effective for some time.

 

[C08]

Now the algae is thinning I can see black which presumably is mould so tomorrow i think some diluted bleach followed by a PM wash off. Poor sail, it has only been out half a dozen times and looks 20 years old!

 

[Easticks28]

I have a similar issue with my awning. After the use of PM, is re proofing required ?

 

[MoodySabre]

I have a similar issue with my awning. After the use of PM, is re proofing required ?

I have often treated my sprayhood with PM but never reproofed it.

 

[Easticks28]

I have often treated my sprayhood with PM but never reproofed it.

Thank you.

 

[VicS]

Now the algae is thinning I can see black which presumably is mould so tomorrow i think some diluted bleach followed by a PM wash off. Poor sail, it has only been out half a dozen times and looks 20 years old!

Be careful with hypochlorite bleach on polyester sail cloth. It can turn the cloth irreversibly yellow. Try a small patch or try an oxy- action bleach such as Vanish

 

[C08]

Be careful with hypochlorite bleach on polyester sail cloth. It can turn the cloth irreversibly yellow. Try a small patch or try an oxy- action bleach such as Vanish

Thanks for the warning - a hard choice between yellow or black!

 

[SteveIOW]

Have recently tried using Patio Magic to clean green algae from leach and foot of furling genoa (the UV strip is white). Mixed it at 4 to 1 and applied liberally with brush. Have left it for four days but there has been little or no effect and the green remains. Any ideas please on why it's not working.
Have done the treatment with sail spread out in garage so that it's not diluted by rain or blown away by wind. Garage has window in wall and back door but not as much daylight as outdoors. Don't know if this or temperature is relevant.

 

[RJJ]

Thanks for the warning - a hard choice between yellow or black!

oxygen bleach - you can buy the powder on eBay for pennies. It's Vanish but cheaper.

I think it's what the sailmaker uses if you ask him to wash your sails. It definitely kills the spores...it might not entirely shift the black stains, but it won't actually harm the sail.

 

[Iliade]

Have recently tried using Patio Magic to clean green algae from leach and foot of furling genoa (the UV strip is white). Mixed it at 4 to 1 and applied liberally with brush. Have left it for four days but there has been little or no effect and the green remains. Any ideas please on why it's not working.
Have done the treatment with sail spread out in garage so that it's not diluted by rain or blown away by wind. Garage has window in wall and back door but not as much daylight as outdoors. Don't know if this or temperature is relevant.

Not sure if sunlight and temperature have an effect but I'm pretty sure I read somewhere that rain does help once the pm has dried.
Also check the concentration of the active ingredient (BAC) in your pm. It is used as a sanitiser and because of CV-19 became almost impossible to get and then very expensive when it did reappear on the market.

It was as per here. I'm unaware of it changing, but...

 

[jonic]

Have used wet and forget to great effect on my Bimini and Sprayhood.

 

[jwilson]

I have always understood that bleach definitely damages nylon and makes it go yellow, but does not affect polyester/terylene/dacron other than helping get rid of algae green and black mildew staining. The ingredients in Patio Magic also reduce algae staining but rather slower than bleach.