Canvas hoods and mildew

[Caliban]

Just been to the boat after a fairly long period. I was expecting things to be much worse than they were.

As I expected the entire boat is covered in that green mildew stuff. It washes off the hull, deck and upperworks easily enough but I have a canopy made from that very thick canvas. It is tan in colour normally but is currently a khaki tone from the aforementioned mildew.

Any ideas how I can remove this stuff? I found scrubbing furiously will get rid of it only partly.

Bearing in mind the boat is in a marina (non tidal) I will need a solution that will keep the enviro-types happy. I can just imagine the reaction and the resultant lynch mob should I use something that leaves a slick, or deep detergent bubbles floating about. Would steam cleaning do the job?

Anyone have any experience of this? All suggestions welcome.

Thanks

 

[Stork_III]

Paint it with 4:1 solution of Patio Magic, when dry. Go home and let the rain do the rest.

 

[Caliban]

Paint it with 4:1 solution of Patio Magic, when dry. Go home and let the rain do the rest.

I had never heard of this stuff before, its a possible solution I think. Does the mildew/algae wash off without trace?

I see it is biodegradable to keep the enviros happy, but it says for use on hard surfaces. Any experience on 'flexible' surfaces?

Thanks

 

[PEJ]

If it is green then it is algae. You can jet wash it off and it does quite a good job. I took mine home and hung it over a fence because spraying it on the ground just makes the water gather in puddles.

Any chemical treatment you are advised to use will be to kill the algae. I have seen advice given to use patio cleaning chemicals and car canvas cleaners also. Each advisor says they worked for them. All that matters is that the chemical used kills the algae without damaging the canvas so you have to strike a balance between deadly to algae and gentle to canvas.

 

[Marley's_Slave]

I had never heard of this stuff before, its a possible solution I think. Does the mildew/algae wash off without trace?

I see it is biodegradable to keep the enviros happy, but it says for use on hard surfaces. Any experience on 'flexible' surfaces?

Thanks

When I used Patio Magic (applied when dry with a brush) on my boat's spray hood, the greeness had gone within a couple of hours - no need for washing off. The green just disappeared and that was several months ago and it hasn't returned.

 

[Caliban]

When I used Patio Magic (applied when dry with a brush) on my boat's spray hood, the greeness had gone within a couple of hours - no need for washing off. The green just disappeared and that was several months ago and it hasn't returned.

I'm warming to this idea with each post.

Canvas or plastic spray hood, may I ask?

 

[stranded]

When I used Patio Magic (applied when dry with a brush) on my boat's spray hood, the greeness had gone within a couple of hours - no need for washing off. The green just disappeared and that was several months ago and it hasn't returned.

Ditto - did oursbwith a garden sprayer thing. Teak decks too. It really is like magic!

 

[Bat21]

I would be careful of some patio cleaners or mould killers because they contain bleaching agents which will eventually rot your canvas.

What you are looking for a surface biocide which will kill the spores and prevent their regrowth for a period such as Borocol 10RH. A diluted version of the chemicals used in Borocol is marketed by Polycel as Polycel mould killer, readily available in diy stores. Spray or paint on, leave for a few days then simply wash with soapy water.

 

[Bandit]

Don't pressure wash.

I use Boracol on the canopies of my boat, soaks in and lasts 6 months, also on my wifes soft top car and of course the teak deck

 

[PEJ]

Borocol 10RH contains Disodium octaborate tetrahydrate and Alkyl Dimethyl Benzyl Ammonium Chloride. Both are algicides, well a fungicide and an algicide strictly speaking.

http://www.biokilcrown.co.uk/csi/1540096/f/pdf/boracol_10rh_msds1.pdf

Bleach is Sodium Hypochlorite so be careful if the ingredients include that. (Borocol 10RH doesn't.)

I have seen someone recommending this product: http://www.algonorganics.co.uk/

But as far as I can tell it is 18% Ethanoic Acid to be diluted to 4.5%. That would probably zap your algae though!

 

[Marley's_Slave]

I'm warming to this idea with each post.

Canvas or plastic spray hood, may I ask?

Canvas mate, heavy duty stuff with plastic windows which incidentally must be kept away from the Patio Magic.

 

[Caliban]

. . . . which incidentally must be kept away from the Patio Magic.

Thanks for that added info, although I would probably have done that anyways, just to be on the side of caution.

Thanks also for all the other suggestions, I'm giving them all consideration.

Keep em coming

 

[Marley's_Slave]

Perhaps followed with a coating of Fabsil to protect from the rain, sea etc.

 

[tinkicker0]

Just been to the boat after a fairly long period. I was expecting things to be much worse than they were.

As I expected the entire boat is covered in that green mildew stuff. It washes off the hull, deck and upperworks easily enough but I have a canopy made from that very thick canvas. It is tan in colour normally but is currently a khaki tone from the aforementioned mildew.

Any ideas how I can remove this stuff? I found scrubbing furiously will get rid of it only partly.

Bearing in mind the boat is in a marina (non tidal) I will need a solution that will keep the enviro-types happy. I can just imagine the reaction and the resultant lynch mob should I use something that leaves a slick, or deep detergent bubbles floating about. Would steam cleaning do the job?

Anyone have any experience of this? All suggestions welcome.

Thanks

The Goole curse. The algae is caused by the dust from the fertiliser company down the road, the dust gets blown in the wind.
I have used starbrite cover cleaner in the past with so so results.

The main problem at Goole seems to be the stitching that gets attacked by the chemicals in the fertiliser. My stitching is certainly starting to fail after 2 years in Goole and my covers are only 6 years old and were perfect before the move.
During winter I have a large tarp over the boat to keep the covers dry and algae free, but the downside is the wear caused by it flapping in the wind. Sunbrella is not that abrasion resistant.
When I get my new covers made, I will specify heavy duty vinyl coated, acrylic composite. It doesn't look as good as sunbrella but you can give it a good scrub or even pressure wash it apparently. Far more abrasion resistant too.

Will have to try the patio magic. Do you just paint it on and leave it?

Edit: also used 303 hi tech fabric guard to reproof the covers a couple of times. Keep this away from plastic windows too as it melts them.

 

[PEJ]

Are you going to take the canvas off when you clean it?

If not always keep in mind that a chemical you use for one thing may be detrimental to something else. When you wash the acid off it may run over your nice wax coat on the hull and wash it away, for example.

 

[Caliban]

Are you going to take the canvas off when you clean it?

If not always keep in mind that a chemical you use for one thing may be detrimental to something else. When you wash the acid off it may run over your nice wax coat on the hull and wash it away, for example.

My plan is to do it in-situ.

I'm ashamed to say I have no nice wax coat to spoil. Even so, I will take as many precautions as I can to avoid area damage.

At the moment I am leaning toward hand painting with a brush, meaning I can apply sparingly and with greater precision.

 

[KINGFISHER 8]

I've painted Patio Magic on to beige coloured canvas covers .... I don't remember diluting it and it worked very well. Just left it without washing it off. Got rid of all the green.

 

[Bandit]

With Boracol

Paint it on , a dry day leave to dry job done, it will die off in the next 2 to 3 weeks after a month clean and free of slime for 6 months.

I would not put bleach on to my canvas.

 

[TSB240]

I had bad algae growth on UV strip , dodgers , spray hood and even in a laminated sail. All were treated liberally with neat patio magic and left to be rinsed off by the next rain storm.
There is no sign of degredation of stitching or materials and I am reassured that Patio Magic has a algacide as an active ingredient (NO BLEACH )which has prevented recurring discolouring for nearly 12 months now.
It is also very effective in eliminating algae build up under toe rails and in the nooks and crevices that a brush cant reach.

It will do nothing for Black Spotted Mildew.

 

[Caliban]

Thanks everyone for the input.

I am glad I asked. I had never heard of Patio Magic before yesterday.