A non-waterproof fabric cannot be made fully waterproof.
Although there are waterproofing sprays available to use on most types of fabrics, they are never able to make something fully waterproof.
You can, however, make a fabric repel water or other forms of liquids.
There are numerous products available on the market that are effective in making items and fabric more waterproof.
Although these products mostly come in the form of a spray, some waterproofing products can be washed into clothing items and fabrics.
There are three main ways you can make your jacket more water-resistant.
The first way is by simply spraying it with a waterproofing spray.
The second method is by waxing the garment. And the third way to make your jacket more resistant to water is by soaking it in a waterproofing solution.
Here is how you do it:
Method One: Coating with A Waterproofing Spray
1. Choose A Durable Water-repellent or Waterproofing Spray
Durable Water-repellent, or DWR, is readily available at most outdoor stores or can be purchased online.
Although most sprays work for a range of materials, it is best to find one that is specific or inclusive to the type of material your jacket is made from.
2. Wash Your Jacket
Run your jacket through a wash cycle with technical fabric wash to get rid of any dirt or residue.
Any residues left on the jacket will result in the water-repellent spray not adhering correctly to the fabric.
Once washed, let your jacket dry.
3. Lay Out Your Jacket
When dry, lay your jacket flat on a piece of cardboard.
Placing cardboard underneath the jacket will not only protect the floor from being sprayed but will also protect the fabric from anything on the ground.
Ensure to lay the jacket out straight and without any creases.
Creases in the fabric will result in the water-repellent spray not going on evenly.
4. Apply the Waterproofing Spray
Hold the spray bottle about 6 inches above your jacket and begin to spray.
Move the bottle back and forth over the jacket to ensure the spray goes on evenly.
When you have applied a thin and even layer on one side, flip the jacket over and repeat steps 3 and 4.
5. Wipe Away Excess Liquid
Using a clean cloth, wipe away any of the excess liquid on your jacket.
Once any excess liquid is removed and there is an even but thin layer of water-repellent spray on your jacket, hang it up to dry.
Do not wear the jacket until it has dried out completely.
Method Two: Waxing the Jacket
1. Choose a Wax
For this method, you will need to use a wax that is made to waterproof canvas or natural fiber fabrics.
Your jacket should be made from natural fibers too, for this method to work.
Synthetic fibers do not absorb wax as well as natural fibers and may not form a proper waterproof coating.
2. Melt the Wax
Melt the wax in a double boiler.
Depending on the size of your jacket, you will need about 4 oz of paraffin wax or beeswax.
3. Apply the Wax to the Jacket
Once the wax has melted, use a paintbrush to apply a thick layer of wax over the jacket.
Make sure to use even strokes and work in sections to fully cover all areas of the jacket in an even coating.
4. Melt the Wax into the Fabric
After you have applied the wax over the jacket, melt it into the fabric using a hairdryer.
Use the hairdryer on high heat and continuously move it over the jacket.
This should be done for about 5 to 10 minutes, or until the wax liquifies and infuses with the fabric.
Allow the wax some time to cool then reapply to areas that you may have missed.
5. Let Cool and Reapply
Add wax to the jacket to fill or even out areas that need it.
Repeat step 4 if necessary.
6. Allow to Cure
Hang your jacket in a well-ventilated area to cure for at least 24 hours.
If the wax still feels damp and sticky, leave the jacket to cure for a further 12 hours.
Method Three: Soaking the Jacket in a Waterproofing Solution
1. Prepare the Ingredients
For this method, you will need laundry detergent and alum, or aluminum potassium sulfate.
The water-soluble soap along with the alum causes a reaction that results in forming a waterproof layer over the top of the fabric.
It is best to use a detergent that does not have any extra chemicals or scents.
2. Wash and Dry the Jacket
Prepare the jacket by running it through a wash and dry cycle.
This will remove any residues or dirt left on it.
3. Create the Detergent Solution
To create the detergent solution, combine 8 liters of hot water with 2 cups of detergent.
4. Submerge the Jacket in the Detergent Solution
Add your jacket to the container with the detergent solution and submerge it.
Ensure the whole jacket is saturated in the solution.
Once saturated, remove the jacket and ring out the excess water.
Then, hang it up to air dry.
Step 5: Create the Alum Solution
While the jacket is airdrying, prepare the alum solution.
Combine 8 liters of hot water with 1 cup of alum.
Stir the solution to combine it properly.
6. Soak the Jacket in the Alum Solution
When the jacket has air dried completely, soak it in the alum solution.
Be sure to submerge the jacket in the solution and allow it to soak for at least 2 and a half hours.
Make sure the entire jacket stays submerged while soaking.
After it has soaked, hang the jacket up to air dry once again.
Once it has dried completely, it is ready to wear!
Although durable water-repellents work, they are not permanent solutions.
Durable water-repellents also do not make a jacket waterproof, it simply adds a water-resistant layer to the garment.
After time, durable water-repellent will need to be reapplied.