Intrepid outdoor adventurers who brave rain or snow frequently quickly learn the value of waterproof fabrics. If you have a favourite cotton bag or other clothing that isn't waterproof, you may be faced with a dilemma about whether to keep it and risk damaging the contents or replacing it with something more expensive but waterproof. Fortunately, waterproofing cotton fabric is neither expensive nor difficult.
Make the wax
Place all of the wax inside the small pan and the small pan inside the larger pan on the hob.
Add water to the larger pan until it rises 5 cm (2 inches) along the side of the smaller pan.
Turn on the heat until the water begins to boil and then reduce to a simmer.
Add water to the larger pot every time there is less than 2.5 cm (1 inch) of water remaining.
Turn off the heat when both waxes are melted and mixed together.
Pour the melted wax into a plastic mould and allow to solidify overnight.
Wax the fabric
Lay the cotton fabric to be waterproofed flat on a large, stable surface like a table.
Rub the waterproofing wax hard against the fabric until you cannot add anymore.
Turn the hairdryer on high and sweep it over the waxed cotton fabric until the wax melts into the fibres.
Repeat three times for a total of four coats on each side of the fabric. The fabric will initially be darker and stiffer with the added wax, but this will ease in time.