Making clothing water-resistant using spray products available at hobby shops, fabric stores and some big box stores, is easier than you think. People who work outdoors or are planning a camping, backpacking or bicycling trip often waterproof their clothing if wet weather is in the forecast. Wearing water-resistant clothing is a sure way to stay dry and warm, especially in cold weather when body heat can melt that snow that gathers on jackets and sweaters.
Choose a water repellent that has been manufactured for the type of fabric you are spraying. Some suppliers have different products for synthetic fabrics and natural fabrics. If the clothing you want to waterproof is a blend, choose a spray that works with synthetic fabrics.
Launder or dry clean the garments before applying the spray. Make sure that the garments are completely dry, especially if you are applying the product to heavy fabrics like denim or corduroy.
Hang the clothes so that you have access to all parts of the garment. Although the products are safe to put on clothing, it's a good idea to work with the spray outdoors or in a well-ventilated space.
Apply a small amount of the spray to a seam inside the garment. Check it once it dries to verify that the fabric does not fade. If fading occurs, you'll have to decide whether you would rather have a water-resistant garment or one that retains its current appearance.
Spray all parts of the clothing according to the directions on the can. Some sprays require that you heat the item after spraying by either placing in a hot dryer, ironing the fabric at the highest heat setting recommended for the fabric or by blowing a hot hair dryer over all parts of the garment.
Once the spray dries, sprinkle a few drops of water on the fabric to test it for water resistance. Reapply if the material absorbs the water.