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​How to Waterproof a Boat Canvas


It’s easy to hitch a boat to a dock and forget that the top of the boat needs to be waterproof as well. If you want to be ready for when it rains, you should do more than just acquire a boat canvas. You’ll want to ensure that this canvas is waterproof enough to protect the top of your boat from the elements without letting issues like mildew linger. Here’s how to waterproof a boat canvas.

Why Waterproof?

Waterproofing a boat canvas can feel like redundant work. After all, if a boat canvas keeps water from the rest of the boat, it’s doing its job, right? But a canvas can keep out the water naturally without doing a great job.

Here’s the problem: some fabrics aren’t naturally waterproof in the traditional sense. They might block out water, but they might absorb plenty of water, too—leaving plenty of room for mildew and other problems.

Making sure that your boat canvas is waterproof will help you block out issues like rain, while keeping the boat dry enough to reduce issues with scent, mildew, and a host of other problems that creep up with poor water management.

Different Boat Canvas Fabrics

One common canvas fabric is cotton. Although cotton tends to swell and seal up when exposed to enough water—helping block out much of the water that’s causing the issue—there’s the obvious problem of lingering water in the canvas itself. That’s why many boat canvases have now been replaced with a woven acrylic or vinyl-coated polyester.

In the case of woven acrylic fabrics, the same principles are at work as with cotton: the tight-weave fabric will indeed lock out water. It’s also waterproof enough to stand up to stains and a host of other issues, such as UV damage.

Tips for Waterproofing Your Canvas

There are a few things you need to be aware before you start waterproofing your canvas:

  • Don’t use a silicone-based treatment on acrylic canvas, as this will be largely incompatible with the treatment already on the canvas. Instead, look for a fluoropolymer-based treatment that’s also compatible with the original finish on the canvas itself. Generally speaking, petroleum-based treatments for acrylic will work better.
  • Clean the fabric first. Cleaning the fabric will ensure that you’re not treating a bunch of debris, but getting into the canvas and its treatment itself. This will give you a more thorough layer of protection that lasts longer. Use a proper cleaning solution with plenty of water, and let it dry thoroughly before you begin the treatment.

For the application of the boat canvas treatment, make sure you follow the instructions on the label of your individual product. You should be working with a healthy, dry bit of canvas. And make sure that the new treatment dries completely before you put the canvas on the boat again.

Keep browsing BoatLIFE for more boat cleaning and sealing products to help ensure your boat is always in the best condition possible.

Life Industries Corporation
4060 Bridge View Drive
N. Charleston, SC 29405
United States of America

toll free: (800) 382-9706
local: (843) 566-1225
fax: (843) 566-1275


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