sunbrella mildew stains

[thirsty boy]

Its that time of year, in the northeast, to get your boat ready. My canvas is desert tan and stains won't go away. I clean my canvas two times a year and have tried many products that don't really work. Some are, mild laundry soap with Clorox 2, 303 fabric cleaner, lasso, on and on. I am now seeing, 303 mold & mildew cleaner & preventer, also starbrite mildew stain remover. Has anyone had success with these or any other product.

 

[wpc691]

Wet N Forget works well for me. I apply every 2-3 months.

 

[Alaskan Sea-Duction]

So I have been battling mold all winter long. In the past I tried the method that Sunbrella suggests. However, taking the Bimini top down onto the dock for cleaning is a pain. AND I don't care what folks say, but the top shrinks about 2 inches when you take it down and try to reinstall it. I have ripped zippers.

I started to use this stuff a few years ago. I get it from Tractor Supply. I spray it on a sponge mop and apply it to the inside of the canvas. After it sits for a few hours the canopy is nice and pretty.

BUT, it only last a few weeks and also leaves a white film in places where I applied it too heavy.

Experiment: So about a month ago, I cleaned the canopy with the above mentioned product, then plugged in a fan pointed toward the Bimini top. I leave it running 24/7. So far no more mold. So it appears that I have found the secret. Now I need to figure out how to get the white film off my black canopy.

So how do you remove the green moss that grows on top of your canopy or side curtains? I have tries bleach, white vinegar and nothing seems to work very well. And I don't want to get it on my Strata Glass.......

 

[Alaskan Sea-Duction]

Wet N Forget works well for me. I apply every 2-3 months.

Picture?

 

[caltexflanc]

I found their recommendation of 1/4th cup dishwashing liquid and 1 cup bleach to work quite well for removing mildew type stains from Sunbrella. Then protect with 303. We had a lot of Sunbrella fabric on our boat, both exterior cushions and interior furniture upholstery.

https://www.sunbrella.com/en-us/how-to-clean

 

[rslifkin]

Any time I've had mildew on the underside of my Sunbrella bimini, I've physically scrubbed it off with a stiff bristle brush (dry). Then if needed, clean further. Keeping the covers well treated with 303 dramatically reduced the start of growth. And it's much easier to remove if you do it right when it starts.

 

[Alaskan Sea-Duction]

I found their recommendation of 1/4th cup dishwashing liquid and 1 cup bleach to work quite well for removing mildew type stains from Sunbrella. Then protect with 303. We had a lot of Sunbrella fabric on our boat, both exterior cushions and interior furniture upholstery.

https://www.sunbrella.com/en-us/how-to-clean

The problem with me is that this solution can not be used on the "inside" of my canopy as I have carpet and Strata glass.

 

[thirsty boy]

I do know the canvas was stitched with Tenara thread and should hold up to some bleach.

 

[kchace]

Its that time of year, in the northeast, to get your boat ready. My canvas is desert tan and stains won't go away. I clean my canvas two times a year and have tried many products that don't really work. Some are, mild laundry soap with Clorox 2, 303 fabric cleaner, lasso, on and on. I am now seeing, 303 mold & mildew cleaner & preventer, also starbrite mildew stain remover. Has anyone had success with these or any other product.

Once a year, I soak any Sunbrella that needs it in a plastic washtub almost full of water (Say 3-4 gallons) with a cup of bleach and a dash of ordinary laundry detergent. (This is per Sunbrella's suggestion) Leave the Sunbrella in this solution for at least an hour - check if its clean and if not, swish it around and leave it longer. This *completely* cleans the Sunbrella (including tough bird stains). After this soak, rinse in clear water, then saturate in a mixture of (Scale up as required) 1 quart hot water, 1 tablespoon baking soda (sodium bicarbonate), 2 tablespoons Washing Soda (sodium carbonate), 2 tablespoons trisodium phosphate (TSP). Allow to dry but do not rinse this mixture off. This mixture comes from a test done by Practical Sailor and works very well to keep the mildew at bay. After thoroughly dry, liberally coat with 303 protectant. Of course this requires that the Sunbrella be taken down.

Ken

 

[Bacchus]

As Ken says soaking in bleach mild soap solution is best but requires taking it down.
303 Fabric Guard works best when applied in multi light coats (vs heavy soaking) while the sunbrella is suspended and it fill sun on a hot day. They also recommend leaving the 303 out in the sun and not using directly from a cool storage area. If you get moisture on the inside I have had success with treating both sides.

 

[Comodave]

Glen Raven had a booth at the Annapolis Power Boat Show and had a piece of Sunbrella sitting in a bottle of full strength Clorox and it had not hurt the Sunbrella. I have used Mildew Stain Remover on some fabrics and it worked great, but I have not tried it on Sunbrella.

 

[caltexflanc]

Boats have different designs, but I used to wash my stamoid biminis by taking a ladder up to the flying bridge and using a very soft brush mounted to a long handle.

 

[Alaskan Sea-Duction]

So have you all had any issues with it shrinking when you take it off?

 

[kchace]

Glen Raven had a booth at the Annapolis Power Boat Show and had a piece of Sunbrella sitting in a bottle of full strength Clorox and it had not hurt the Sunbrella. I have used Mildew Stain Remover on some fabrics and it worked great, but I have not tried it on Sunbrella.

I've used some pretty concentrated mixes of bleach on Sunbrella many times - no ill effects, too. I think the typical Mildew Stain remover like X14 is mostly bleach. If so, it should be ok for spot treating.

Ken

 

[kchace]

So have you all had any issues with it shrinking when you take it off?

Yes.

 

[Comodave]

I don’t usually take mine down. On our current boat we have 2 hardtops instead of biminis. On previous boats when we did take the canvas down to wash it we would put it back up while it was still wet. So it didn’t really seem to shrink.

 

[wpc691]

Picture?

Sorry about the rotated picture - they just come out that way. My bimini is Captain Blue and I keep after it with 303, so no (visible) mildew issues. However, we have a big pool cabana that’s white Sunbrella. Keeping up with the mildew in the summer was a nightmare until I tried this stuff. I also use it on our showers in the house - using this every couple of months, they only need a light scrub every couple of years. Not cheap, but well worth it. I think I got it at Lowe’s. As always, YMMV.

 

[Alaskan Sea-Duction]

I have found a fan running 24/7 helps.

 

[Comodave]

I have found a fan running 24/7 helps.

Or move somewhere drier...

 

[thirsty boy]

As soon as I get a chance I will try some of your suggestions. I think my biggest problem is moisture from inside. This is my second enclosure and I have two extra vents installed on the side curtains to help, maybe a small fan pointed straight up will help.

 

[Alaskan Sea-Duction]

Or move somewhere drier...

Well yes, but give up the best cruising grounds in the world?

 

[Comodave]

Well yes, but give up the best cruising grounds in the world?

I guess you have to decide what non mildewed tops are worth??? Just kidding.

 

[C lectric]

Once a year, I soak any Sunbrella that needs it in a plastic washtub almost full of water (Say 3-4 gallons) with a cup of bleach and a dash of ordinary laundry detergent. (This is per Sunbrella's suggestion) Leave the Sunbrella in this solution for at least an hour - check if its clean and if not, swish it around and leave it longer. This *completely* cleans the Sunbrella (including tough bird stains). After this soak, rinse in clear water, then saturate in a mixture of (Scale up as required) 1 quart hot water, 1 tablespoon baking soda (sodium bicarbonate), 2 tablespoons Washing Soda (sodium carbonate), 2 tablespoons trisodium phosphate (TSP). Allow to dry but do not rinse this mixture off. This mixture comes from a test done by Practical Sailor and works very well to keep the mildew at bay. After thoroughly dry, liberally coat with 303 protectant. Of course this requires that the Sunbrella be taken down.

Ken

I have uses the Practical Sailor mix now a couple times. Not on the Sunbrella but in my truck. Humidity built up over a winter in storage and made a mess.
Mixed that stuff up, sprayed the upholstery and no more problem.

I did go back later and wipe the ever so slight whitish cast off but the seat fabric has shown no hint of more mildew since, 3 yrs.

 

[Taras]

Buy a black canvas top and you’ll never actually see any mildew��.

 

[Alaskan Sea-Duction]

Buy a black canvas top and you’ll never actually see any mildew��.

LOL I have a black top and I have mold.

 

[Comodave]

LOL I have a black top and I have mold.

I’m telling you that when we lived in Arizona we never had mildew on our canvas... It may take a really big trailer for your boat though.

 

[Alaskan Sea-Duction]

I’m telling you that when we lived in Arizona we never had mildew on our canvas... It may take a really big trailer for your boat though.

Yeah, but they have big snakes in Arizona. I will stay with the bears..

 

[HypnoBob]

X14 Mildew and Stain. Use lightly. Start at one end and back away as you spray. Take care if it drips on your clothes, it will bleach them. You can watch the mildew disappear within seconds. Get it at the grocery store.

 

[MichaelE]

My boat Detailer tells me to leave it in the pool overnight. I have not tried this yet but will report back I have talked with friends that say this works.

 

[Alaskan Sea-Duction]

My boat Detailer tells me to leave it in the pool overnight. I have not tried this yet but will report back I have talked with friends that say this works.

Well I just haven't filled the onboard pool yet!!!