We tested 10 of the best canvas cleaners, plus two budget options to find the best product to restore your sprinklers and sail covers to their best condition

Canvas cleaner tested by the Yacht Monthly team. Credit: Graham Snook

With the appearance of winter with algae green sail covers and spray covers, the Yacht Monthly team began to look for the best canvas cleaner.

The beginning of the season is here. If your boat is neglected in the wet and cold winter, it may already show a hint of green.

Nothing can see the blight of mold and algae more than on her spray hood and sail hood, which grow in large numbers on wet and dirty surfaces. It's time for spring cleaning.

When we started cleaning Sadler 32's seemingly neglected canvas, we found a dizzying array of canvas cleaners.

There are more than six canvas cleaners on Chandler’s shelves, as well as some daily household items that are rumored to be useful.

Before you start cleaning, prepare everything you need to do the job properly. Credit: Graham Snook

When testing canvas cleaners, we are always looking for cleaning power, ease of use, and the ability to prevent future growth.

When we are playing with chemicals, safety in use and its impact on the environment are very important.

Worryingly, some are marked as "extremely dangerous to skin, eyes and marine life."

Some canvas cleaners were clearly winners and completed their claimed work in a short period of time.

Others are more difficult to judge, and the end of the new season may reveal more of their true performance.

Currently, our test is based on the results obtained that day.

Want to clean canvas seats? Check out YBW's guide to the best boat seat cleaners.

For convenience, the 10-foot sail cover was removed from the boom.

Algae grows abundantly on the outer underside of the sail cover and less on the drier upper side.

We marked 13 equal stripes on the width of the sail cover and marked them, assigning a product to each stripe.

In view of the dangers of some of these chemicals, we wear waterproof shoes, rain boots and gloves, and spread plastic sheeting under the sail cover to prevent leakage into the sea.

Then, we strictly follow the instructions on the packaging as much as possible, taking care to avoid contaminating adjacent parts.

In the place where scrubbing was prescribed, this took two minutes.

Then we hung the cover to dry and compared the before and after photos to determine which produced the best results.

Among these 13 spaces, 3 are controlled areas where ordinary household items are used: non-biological washing powder, washing liquid and plain water.

Make sure you always read the instructions. Credit: Graham Snook

Before I started cleaning, I asked some experts for advice.

Tecsew in Gosport focuses on boat canvas, from cushions to cockpit tents.

Try to turn your boat occasionally, the north-facing side will suffer worse growth

Director John Brand shared his advice on canvas maintenance:

The translated Muffa Net description is vague.

In spite of the warning that it is "a great danger to eyes, skin and marine life," the solution was sprayed directly from the bottle, soaked the fabric, and then allowed to soak, and then rinsed.

We don't like the idea of ​​bleach-based solutions spreading through the air and into the lungs and eyes, so proceed with caution.

It removes quite a lot of dirt, but some scrubbing is required to remove the dirt from the canvas.

This is the strongest bleach solution we have tested.

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Size: 750ml Active Ingredients: Sodium Hypochlorite, Active CI. <5% Use: Spray based on reviews Price: £9.95

After quickly brushing off, moisten the fabric with water, and then use a brush to "apply" the neat Renovo Boat Canvas Cleaner to the fabric.

We leave the solution for 45 minutes, then scrub and rinse it.

Compared with some other cleaners, this is a slightly more complicated process and requires more stages.

The result is reasonable, but it seems to be more dependent on the scrubbing we do, because the grooves on the float prevent the fabric from being scrubbed properly, so the dirt is still visible.

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Size: 500ml Active Ingredient: Non-ionic Surfactant Usage: Brush on Comment Price: £13.25

A simple and easy-to-use cleaner, we spray it, scrub and rinse it off.

It advertises that it is safe on marine fabrics and does not come with any major environmental warnings.

It is not based on bleach, and it seems to have a much smaller effect on the color of the canvas compared to other products.

It produces impressive results, even in areas where the fabric is not easy to scrub.

It also contains PTEF or Teflon, which is designed to reduce UV damage and repel dirt, although we cannot test this claim.

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Size: 1 liter Active ingredients: non-ionic surfactant, EDTA, d-limonene, PTEF Use: spray Comment price: 20.95 pounds

The product is designed for any outdoor fabric, including tents and garden furniture, and it is fast and convenient to use.

It also claims to maintain water resistance, but we cannot accurately test it.

Wet the canvas first, then gently scrub with the solution before rinsing.

Obviously, the green mold has been treated to a large extent, and the canvas has returned to its original blue color.

This is the easiest to use and most effective of all products.

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Size: 300 ml Active ingredient: <5% non-ionic surfactant, benzisothiazole Purpose: Dilute 100 ml in 5 liters of water Review price: 8.95 GBP

Before applying the solution, the cloth must be dampened, then gently scrubbed, and then rinsed.

It works well, supplemented with a little elbow grease.

Except for the most heavily dyed part on the cover, it gives the fabric a beautiful bright blue, so it definitely played a role.

Adding natural cleaners such as limonene seems to be very effective, but it is not too irritating, although I cannot guarantee how effective it will be on the fabric.

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Size: 300ml Active ingredients: <5% non-ionic and cationic surfactants, EDTA, d-limonene Uses: 1:4 dilution with water Review price: 14.95 pounds

Iosso is a chlorine-free cleaner that claims to be able to treat stains as well as mold and mildew.

Instructions Use a sponge to apply, soak for 15 minutes, then gently scrub and rinse the canvas.

Most of the green was removed, but the darker stains were not removed.

This cleaner may be more gentle on fabrics than other products, and if soaked, it may be better at removing mold.

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Specification: 340 g Active ingredient: Pentasodium thiophosphate Purpose: Dissolve 1 scoop per liter of water Comment price: 24.95 GBP

Wessex Sail Cleaner can be sprayed and wiped clean without rinsing.

It is a bleach-free product, so it is completely safe for your stitches and it is also biodegradable.

After a lot of spraying, this scented cleaner smells like school corridors all over the world.

After letting it soak for a few minutes, we wiped it, and a lot of dirt disappeared, but it needs a little scrub to remove more stubborn stains and won't make the fabric look particularly clean.

This may be more effective on more waterproof canvas; it solves the most serious dirt, but it is not completely wiped clean.

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Size: 750 ml Active ingredients: tetrasodium ethylenediaminetetraacetic acid, ethanol ethoxylate Usage: spraying Comment price: £11.95

As a cleaning product easily available from DIY stores, sugar soap has been around for a long time as a way to remove almost any type of dirt around the house.

It's not expensive, and the effect is mediocre, as long as you scrub it well.

It is easy to apply using a spray bottle, or it can be dissolved in water and applied with a sponge.

It is easy to rinse off, although it does contain a fungicide, so if it gets into the water, it may not be good for the environment.

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Size: 5o0ml Active ingredients: methyl isothiazoline, benzisothiazole, <5% non-ionic and anionic surfactants Uses: spraying, price review: 3.95 pounds

This is a long-lasting product designed to be sponged on the canvas and soak for up to 12 hours or as long as possible, but it should not dry out.

Then it should be brushed before rinsing.

We were able to test this within a few hours, although not the full 12 hours, but found that the canvas dries faster than expected.

This is a more complicated process than other cleaners and produces moderately good results.

Maybe if you keep soaking for 12 hours, the effect will be better, but we question whether this is a realistic expectation.

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Size: 5o0ml Active ingredient: 5-15% soap, <5% non-ionic surfactant Use: Dilute 50ml in 3.5 liters of water Comment price: £11.95

This is a product that the forum cannot highly recommend.

Not a marine product, it is known for preventing mold and growth on all surfaces.

What has been concerned is the very clear warning that the product is extremely dangerous to marine life, skin and eyes.

Therefore, if you want to apply it, you should bite the bullet and do it.

However, it does not contain bleach, so it is safe at this point.

Brush or spray it on a dry canvas and let it dry for five hours.

In our test, the algae changed from green to white and was obviously killed.

The canvas has not become clean, but it may have become clean in time.

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Size: 2.5 liters Active ingredient: 5-15% benzalkonium chloride Usage: 1:4 dilution with water Evaluation price: 7 pounds

The effect of the washing liquid is not as good as we hoped.

The amount of foam generated during scrubbing is annoying and requires a lot of rinsing.

If your canvas is stained with grease, this may be a good choice, but it will not be effective against more stubborn mold stains.

Size: 433 ml Active ingredients: 15-30% anionic surfactants, 5-15% non-ionic surfactants Uses: mixed with water, reviewed price: 1.31 pounds

Non-biological washing powder is designed to be used at higher temperatures, but on the float, we are limited to cold water.

Biomeal may be more effective.

It foams and quickly removes the first layer of dirt.

Despite a lot of scrubbing, it does not treat the underlying dirt well.

Size: 700 g Active ingredient: 15-30% anionic surfactant, <5% non-ionic surfactant, oxygen bleach, soap Usage: Dissolve a scoop in 5 liters of water, review price: 3.50 pounds

Perhaps unsurprisingly, water is a key element in most cleaning methods we have tried.

A good old-fashioned spraying, scrubbing and rinsing plus a stiff brush does a good job of treating surface mold and algae.

It is good enough for government work, although it does not solve the deeper taint.

It shows that regular rinsing and brushing help keep items in good condition.

There are various canvas cleaners on the market.

Generally speaking, the target products designed for this job performed better than ordinary cleaning products, although we were surprised by the performance of sugar soaps.

At less than £4 per bottle, Everbuild Sugar Soap is our best budget purchase.

Many products contain bleach, which can kill mold and algae spores, but there is a risk of weakening the stitching, so we don’t want to use bleach cleaners on the canvas.

Most products contain some form of surfactants and bactericides.

Obviously, these products need to stay away from water and skin as much as possible, especially more aggressive products such as Patio Magic, although this is effective for a long time.

Fabsil Universal Cleaner can work quickly, easily, and efficiently, and there is almost no fuss, with no noticeable fading or damage to the canvas at all. It is also quite cheap, so it becomes our favorite product.

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Followed by Starbrite's PTEF-containing fabric cleaner and protector. This seems to work better than the company's simpler Sail & Canvas Cleaner.

Using a spray bottle, it is easy to use, does not need to scrub too hard to keep the canvas clean, and has the added benefit of protecting the fabric in one product.

No matter what product you use, it is definitely worth refinishing the fabric.

It will not make it completely waterproof, but it will help your canvas to stay in top condition throughout the season.

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