Raw canvas has water-resisting properties, however, if the canvas is not waterproofed, water will seep through it, resulting in mildew build up. Cotton canvas has been the popular waterproof canvas fabric for a long time. The cotton fibers in the cotton canvas swell, when they get wet, thereby sealing the weave. However, cotton canvas has a special affinity to mildew, thus it has been replaced by either woven acrylic or vinyl-coated polyester. The vinyl-coated fabric, unlike the traditional cotton canvas does not breathe, and needs to be ventilated. Condensation causes the fabric to become wet, eventually leading to mildew. On the other hand, the acrylic canvas is a tight-weave fabric, which breathes; stands up to ultraviolet radiation, snubs mildew and resists staining. The only negative factor is its high cost.
How to Waterproof Canvas
For acrylic canvas, silicone treatment is not recommended as silicone is incompatible to it. A fluoropolymer-based product is the best for acrylic canvas. The canvas needs to be cleaned thoroughly and then evenly sprayed with the fluoropolymer-based product. Once the canvas is dry, it can be checked by tossing it in a bucket of water. If the water seeps into the canvas, then the coat was not enough and needs to be sprayed again. Brushing petroleum sealant onto the canvas is also another way of waterproofing. One should ensure that the waterproofing procedure is carried out in a well-ventilated place, preferably outdoors, as the treatment involves fumes, which are not appropriate to be inhaled. The waterproofing treatment does not affect the fabric's other qualities.
Canvas Tent Waterproofing Steps
People who camp in canvas tents, need to waterproof their tents. No matter how durable the tents are, they will eventually leak during the rains. Several methods of canvas tent waterproofing are available, which will keep the tent free from leaks for some period of time. One will need a canvas preservative, paint brush and a ladder to accomplish the task of waterproofing. The canvas preservative can be found in the paint section of any home improvement store. It is advisable to choose a sunny day to waterproof the tent, as it will guarantee the complete drying of the waterproofing material. The ladder is required to reach every nook and corner of the tent. Waterproofing the tent is easier when it's set up, rather than when it's lying flat on the ground. Use the paint brush to apply a thin coat of canvas preservative all over the canvas. When the canvas preservative is no longer sticky to touch, then one knows it has dried.
How to Waterproof Canvas Shoes
Waterproofing will ensure that the canvas shoes remain durable and clean during the time they are worn. A spray-on, containing fluoropolymer, is required to waterproof the shoes. The ones with a silicone base will break down the acrylic fibers within the canvas, causing it to become even more susceptible to moisture. Since the shoelaces do not need to be waterproofed, one can remove them and then apply a thin and even coat of waterproofing spray, onto the entire canvas surface of the shoe. Once the shoes have dried completely, conduct a small test to ensure the shoes are waterproofed. To test the shoes, one can allow a small amount of water to drip on the canvas surface of the shoes. One will need to apply another coat of waterproofing spray, if the water does not bead up on the canvas.
How to Waterproof Canvas Bags
To waterproof a canvas bag, one should begin by cleaning the bag thoroughly inside out. Special attention is to be given to hidden seams in the bag. Small amount of rubber sealant, like the ones used to fix holes in rubber shafts, is to be applied along the entire seam. Spray a silicone-based waterproofing spray, on the entire surface of the bag, giving special attention to the bottom and seams of the bag. As far as the zippers are concerned, no zipper is 100% waterproof. If water seeps through the zippers of the bag, one can use acid-free packing tape to deal with the leak.
The above steps can serve as a guideline for those planning to waterproof their canvas products. The frequency of reapplication of waterproofing spray, depends on the frequency of use of the canvas product. Even if the canvas product has been used in harsh conditions, the treatment should be effective for at least a year.