Guarding against moisture is something that boat owners need to do in order to keep their vessel in top condition. If moisture gets under the boat cover, mould and mildew can begin to form on various parts of the boat such as the seating, railings, appliances and boating instruments. In order to combat this problem, many boat owners use canvas covers over various parts of their boat. However, the covers must be waterproofed in order to work effectively.
Remove the canvas covers from your boat. Though they can be quite large, it is best to perform the waterproofing process when the covers are not on the boat itself.
Clean the boat covers by applying warm water and a non-detergent soap. Use the brush to remove any dirt or debris which has built up on the canvas cover.
Allow the boat covers to dry thoroughly. Try to store the boat covers in a dry place with low humidity to expedite the drying process. Hanging the canvas covers, if you can find a large enough space, will also help the drying process go faster.
Apply the canvas waterproofing spray onto the boat cover. You want to purchase a waterproofing agent that has a fluoropolymer or petroleum waterproofing base if you are trying to seal a woven acrylic or vinyl coated polyester. Silicone agents will not work on canvas boat covers made of these materials. While spraying the boat cover spray in a horizontal direction. Remember that the canvas does not need to be "dripping wet" in order for the waterproofing to be effective.
Allow the canvas to dry completely. Many of the sprays on the market suggest two coats, with the first coat being allowed to completely dry in between.
Spray the canvas in a vertical direction. By spraying the second coat in a perpendicular direction, you will help seal the waterproofing onto the material.
Allow the second coat to dry completely before use.
Traditional canvas made of cotton does not need a waterproofing agent. While some boat owners still use this type of canvas cover, many have shied away from it because mildew forms easily on the exterior of the fabric.