Things You'll Need
Instructions
Clean the canvas before waterproofing. Any dirt or grease on the fabric will get trapped under the agent and have a negative effect on the waterproofing. Scrubbing with a household cleaner is acceptable, but for the best results clean in a washing machine.
Dry the canvas outdoors. This will remove all the water from the fibers without damaging the material, which may happen in a machine dryer.
Lay out the canvas on a flat surface. For the best results, choose a warm day with little wind.
Apply the waterproofing agent in lengthwise strips across the canvas. Waterproofing agents come in aerosol form, which is why it is best to choose a windless day.
Repeat the last step, this time applying the agent width-wise across the canvas, ensuring that all the canvas has been waterproofed. Leave to dry for 24 hours.
Add extra protection by repeating the last two steps on the other side of the canvas. This is not strictly necessary, but is advisable.