How To

    How To Care for Your Boat’s Canvas

    Canvas Care 101

    Marine canvas protects our boats from the sun’s brutality, rain, bird droppings and sundry other evils, as well as shielding us from the elements while we’re embracing the boating lifestyle.

    As with everything else associated with owning a boat, marine canvas requires your attention periodically to allow the canvas to do its job and look good in the process.

    Marine canvas today is made from a variety of materials including cotton, polyester/cotton blend, solution dyed polyester and others.

    Fabrics Primer

    In the early years of sailing the high seas, canvas – a tightly woven fabric made of linen, hemp, or cotton – was pretty much the only option for boat coverings, tents and tarpaulins.

    About four decades ago, technological advances in the textile industry led to the development of synthetic fibers, such as polyesters and acrylics. These materials have proven themselves well suited to the rigors of recreational boating, relegating the canvas of old to more industrial applications. However, we still use the term “canvas” generically to describe the various fabric tops, covers, shades and enclosures one might find on a boat.

    Today’s marine canvas can be made from a variety of materials, including cotton, polyester/cotton blend, solution dyed polyester, pigment coated polyester, acrylic coated polyester, urethane coated polyester, or solution dyed acrylic. Each fabric has its own unique characteristics, allowing you to choose the best material for your particular needs.

    Canvas Killers

    Ironically, one of the biggest enemies of marine canvas is prolonged exposure to sunlight – the sun’s ultra-violet (UV) rays eventually can fade the fabric. Many covers are impregnated with a UV inhibitor to protect the canvas (to some degree), but over the years most boat covers and canvas will be a slightly lighter shade than when the material was new.

    The next is mold, mildew and other nasty stuff that tends to accumulate on canvas, especially those made of cotton or polyester/cotton, because mold and mildew are living organisms, they literally eat the organic cotton fibers in the canvas. What’s more, although the canvas may be completely synthetic, these microscopic villains can attack the stitching – if the thread in the seams is organic, it’s fair game for these gross little creatures.

    Operator error is a common reason for canvas problems. Not installing the canvas properly can damage the fabric from chafing against the boat top’s framework and from being subjected to high-speed wind loads.

    Continuing the theme of operator error, boat owners are notorious for removing wet canvas, wadding it up and tossing it on the dock or in a compartment on the boat – and not thinking about the soggy fabric until it’s time to reinstall the canvas. Chances are that the wet fabric is now a smelly, mildewed mess – bad move, Cap’n.

    David Karpinski, VP of Sales and Marketing for Taylor Made Products®, explains, “We see a lot of canvas ruined because water collects in areas where the fabric isn’t properly supported. The water pools in these low spots, forming an idea environment for dirt, mold and mildew to congregate. In addition, the weight of the water puddles strains the canvas – a situation that can lead to premature canvas failure.

    Karpinski continues, “Your boat’s canvas needs to be supported by adjustable poles or a well-made framework assembly and securely fastened to the boat to make sure the top or cover is taut to allow the water to run off quickly, kind of like a tent”.

    Cleaning the Fabric

    Taking care of canvas isn’t hard; just add this simple task to your boat’s maintenance routine.

    Most canvas experts recommend cleaning the canvas while it’s on the boat, because most of the sections of fabric are rather large and ungainly; however, you can toss smaller pieces of canvas in a washing machine (on the “delicate” cycle), if you like. Don’t put marine canvas in the dryer; hang the canvas on a clothesline or reinstall on the boat to let the fabric air dry.

    The cleaning drill is essentially a matter of using stiff brush to remove loose dirt and debris from the canvas. Hose the canvas with fresh water, then, gently scrub the fabric with a soft brush and a gentle soap (Ivory Snow®, Dreft® or Woolite®). Allow time for the cleaning solution to soak into the fabric, scrub again, and then, rinse with cold (or lukewarm) fresh water until no soap remains on the canvas. Let the canvas air dry.

    Some canvas manufacturers suggest using a bit of chlorine bleach to get rid of stubborn stains; others absolutely forbid using bleach. Your best bet is to refer to the information from the supplier/maker of your boat’s brand of canvas.

    After a thorough cleaning (or every few years), you may need to re-treat the canvas to restore its water-repellent properties. This isn’t difficult; the authorities in this field advocate a spray-on multi-faceted fabric protection formula that is easy to apply by the do-it-yourself boater.

    Because most marine canvas windows are made of clear vinyl or plastic, you should avoid using "window cleaners" to clean them; the ammonia will damage the vinyl/plastic.


    The windows in most marine canvas enclosures are made of clear vinyl or plastic. Take great pains not to use “window cleaners” on vinyl or plastic windows. The ammonia will damage the vinyl/plastic, causing the windows to become cloudy or translucent, and possibly turn a sickly yellow color, rather than remaining transparent.

    Also, the vinyl/plastic cleaning protocols vary by manufacturer; some advise simply rinsing the window and wiping it off with your (clean) hand, some promote using mild soap and a soft cloth, and others advocate aftermarket plastic cleaners. Again, consult your boat enclosure supplier or manufacturer for the best method to clean their specific brands of vinyl/plastic windows.


    Let’s not forget the often-neglected snaps that hold the canvas on your boat. These little fasteners do a lot of work for little recognition.

    Periodically treat both halves of the snaps with a dedicated snap lubricant or a drop of water-displacing oil to prevent rust buildup, a particularly bothersome condition in saltwater environments.


    Stow canvas when it’s 100% dry; don’t put the canvas away wet. Most folks fold the canvas, others prefer to roll the fabric – either way is fine – just don’t fold the windows or they will form permanent creases (and eventually crack).

    Other Items of Interest

    Put the top(s) down if you plan to do some high-speed cruising or are going to trailer your boat.

    If you can see daylight through the canvas seams from inside the boat, or if the fabric develops tears or weak spots, get the canvas repaired immediately, before a small imperfection becomes a big problem.

    Invest in the best canvas you can afford; some say to figure on spending a certain percentage of the cost of your boat on top-shelf canvas – boating isn’t inexpensive and canvas can protect your boating investment, not to mention add to the boat’s resale value when you’re ready to move up.

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