Boat Top/Canvas Maintenance Tips

Boat top fabrics are exposed to everything from UV rays to rain, bird poop and beyond. Giving a boat top regular maintenance helps extend its longevity beyond the warranty. 

Boat tops or canvasses such as Bimini tops can last a decade or two, and are not just aesthetic additions to a boat. They help protect boaters from the elements and keep them comfortable during boat rides. As such, they deserve attention just like any other part of a boat. Here are some tips on how to maintain boat tops.

NOTE: Boat tops are commonly referred to as canvas, so we’ll be using “top” and “canvas” and their plural forms interchangeably. 

Cleaning Boat Top Fabrics

Hose your boat top down with clean water after every ride to keep dirt and debris (and especially bird droppings) from setting in. 

Most boat top fabrics are designed to be water-resistant and breathable, keeping water out while still allowing air and moisture to vent through. Still, mold and mildew buildup can occur from moisture buildup when the fabric is left unattended.

For mold removal and prevention, there are several mold and mildew cleaners available that are safe to use on boat tops. 

However, if you prefer a homemade remedy, mix 1 cup of bleach and 1/4th cup of mild soap per gallon of clean water. Apply the soap and water mixture to the fabric with a soft brush or sponge, and leave it on for at least 15 minutes. Blot the stains with a sponge or towel, then rinse the soap residue off with clean water and let the canvas air dry. Don’t let the soap dry. 

NOTE: Never use a machine washer/dryer or detergents to clean boat top fabrics. Detergents are abrasive and will damage the fabric. Follow the manufacturer’s recommendations for cleaning, and be careful with what solutions you use, as damaging your boat top due to negligent care could void the warranty.

Treating Boat Top Fabrics

Many boat top fabrics are treated straight from the factory to ensure their longevity. However, it’s a good idea to re-treat the fabric from time to time after multiple washes. 

Re-treating a boat canvas helps it maintain its color, breathability and strength. When using a waterproofing and/or fabric guard treatment, use the product on clean, dry material at temperatures of at least 70°F. Spray the fabric until it’s wet, then give the treatment 24 hours to cure.

NOTE: Fabric treatments may be flammable, so keep them away from open flames or sparks. As always, follow the manufacturer’s recommendations for what products to treat boat canvasses with, and the directions on the bottle for how to apply it correctly. 

Cleaning and Treating Boat Canvas Windows 

If your boat top has windows, they need to be cleaned not just for preserving visibility, but to prevent deterioration and sagging. 

Inspect the windows for scratches, holes and tears first, and consider replacing them if they’re damaged. Hand-wash the windows with mild soap and water, then rinse the windows with a low-pressure hose and wipe them down with a soft cloth or towel.  

Use a UV blocker treatment to protect the canvas’s windows from fading, cracking and premature aging. A multi-surface cleaner with degreasers and other cleaning agents might be needed for tougher stains on windows and the canvas fabric itself. 

NOTE: Avoid using glass window cleaners, especially those that contain ammonia, which removes natural oils in vinyl and plastic. Also, don’t use bristled brushes, which can damage or scratch the surface of your boat top’s windows.

Additional Boat Top Cleaning Tips

Aside from the canvas fabric itself and its windows, the fasteners should also be protected. Use silicone spray to lubricate metal fasteners such as zippers on boat tops, or have the zippers replaced periodically. Also, keep a dehumidifier on your boat to reduce moisture and mold when an enclosed top is in use.

As long as you keep your boat’s top clean and well-maintained, it should last for years beyond its warranty’s expiration. Boat tops can also help maximize a boat’s resale value, so keep that in mind when putting in the time and effort to preserve the canvas.