Rain got you down? No need to worry! I recently tested out several methods to waterproof fabric. What follows is a tutorial for several easy methods to waterproof fabric in a eco-friendly manner.
Learning how to waterproof fabric is incredibly useful for a number of DIY projects, including:
- DIY food wraps
- Reusable grocery bags
- Canvas patio covers
- Rain ponchos
What You’ll Need to Waterproof Fabric:
- Plant-based fabric (such as cotton/canvas/linen, etc)
- Wax (in this tutorial I use Beeswax and Paraffin)
- Drying oil (such as Walnut, Tung, or Linseed oil; See this link for the science behind Drying Oils)
- Pine Resin (for food-safe projects)
- Pine Tar (for non-food, outdoor projects)
- Mineral Spirits (for non-food, outdoor projects)
Method 1: Waterproof Fabric with Beeswax and Drying Oil
I used this method to waterproof my new DIY forager’s bag, because I needed the bag to be waterproof and more pliable than a pure wax waterproof fabric method.
First, melt beeswax in a double boiler. I used an old coffee can for this, so that I could store the leftovers for later. used about 4 oz beeswax for my harvester’s bag, which is the size of a reusable grocery bag.
Next, remove the melted was from the heat and stir in the drying oil. I used walnut oil for this project, because it is a food safe option. In general, use a ratio of 2:1 wax to drying oil.
Once the mixture begins to harden, use a spatula or popsicle stick to spread the mixture on the fabric you want to waterproof. Use a fabric made of natural fibers; natural fibers such as cotton are hollow, which allows them to absorb the waterproofing mixture. Be sure to add extra to the seams of your fabric. At this point, it will look like a mess–that’s ok!
Finally, preheat your oven to 300 F, line a baking sheet with foil and place your fabric in the oven. It’s ok if you need to fold the fabric to get it to fit on the baking sheet. The heat will help the fabric to absorb the waterproofing material.
Once the waterproofing mixture is totally absorbed into the fabric, remove it from the oven and lay flat to cool.
Method 2: Waterproof Fabric with Paraffin Wax
I used this method to waterproof a reusable canvas grocery bag, which I will also use to harvest vegetables from my garden this year.
Paraffin wax is very inexpensive and easy to obtain online or at a grocery store. If your wax comes in a large block, the first step is to grate it into fine pieces. Or, obtain paraffin in pellet form.
Preheat your oven to 300. Lay your fabric on a large baking sheet lined with foil, and cover it with a layer of wax pellets. Place the tray in the oven, and allow the pellets to melt completely.
You might need to repeat this step several times to fully cover your fabric, depending on how much you are attempting to waterproof and how heavy the fabric is.
Once the fabric is completely coated, lay it flat to cool. Be sure to cool the fabric unfolded; otherwise, it will dry stuck together and you will need to warm it again to
Method 3: Waterproof Fabric with Boiled Linseed Oil and Mineral Spirits
I used this method for the canvas tarp that acts as a rain splash guard over the wood pile on my porch. This is an incredibly easy method for waterproofing fabric; however, because the materials used can be harsh, this method should be performed only outdoors in a well-ventilated area.
First, mix equal parts mineral spirits and boiled linseed oil. Next, soak the fabric in the mixture until fully coated. Finally, hang the fabric to dry outside in a well-ventilated area for several days. The smell will dissipate after 1-2 weeks.
Important safety consideration: Do not fold the fabric until it is fully dry, and do not fold cloths or other materials that are soaked in mineral spirits or boiled linseed oil. These substances generate heat as they dry, and can be flammable if not disposed of properly. Boiled linseed oil is also not food-safe.
This is a great option if you want to create your own waterproof patio covers, DIY an old-school canvas tent, or waterproof clothing for bushcraft or other outdoor use.
How to Care for Waterproof Fabric
Clean your waterproof fabric in cool water, with a gentle sponge and mild soap at the most. Warm water or abrasive brushes will strip the waterproofing away from the fabric.
These methods to waterproof fabric utilize waxes and oils to coat and fill the fibers of natural fabrics. This means that over time, with wear and tear, the waterproofing will weather away. You may need to re-waterproof your fabric occasionally, depending on how much you use it and under what conditions.
For beeswax or paraffin food wraps, follow the instructions for waterproofing with a food-safe drying oil, and add a small quantity of pine resin. Pine resin will help the food wraps stick together and keep them pliable. Read here for tips to sustainably harvest pine resin.
For outdoor, non-food applications, consider adding pine tar to increase pliability, durability, and an added layer of waterproofing to your fabric.