​How to make a Cotton Canvas Tent Water Proof

Posted by Douglas Gray on 14th Nov 2014

Cotton Jacket

How to make a Cotton Canvas Tent Water Proof is possible if you know how to approach this and know what to expect from it when the job is completed. The water proofing of the exterior of a canvas tent is required periodically since the UV rays of the sun will break down this protection.

One of the most common mistakes in the water proofing process for cotton or canvas tents is the painting of them with a material that contains plastic as the final coating when the paint dries. This does stop rain from penetrating the canvas, but also prevents it from breathing. When a canvas tenet is occupied, moisture is accumulated on the inside. This has to be expelled. If the tent is covered with a plastic, this does not occur. In addition it is not easy for fresh air to enter the tent. Because of this condensation will form on the interior of the tent causes items to become wet.

The requirement of waterproofing a canvas tent, while not sealing up the holes between the fibers is a trick that is not easily accomplished unless you know what you are doing. To do this would require the canvas to be protected with a water repellant. This can be done mainly in two fashions. Oil repels water and so do waxes and soaps. The choice you use will determine how long it lasts and just how waterproof your cotton tent will be. 

The term oilskin is slightly misleading. This is a waterproofing technique that uses paraffin to make the cotton material waterproof by repelling the moisture so the cotton fibers will not absorb it. Because paraffin wax and cotton are natural materials, this process will have to be reapplied over time, generally annually, to provide the type of protection you need from the rain. This was the waterproofing processes used for many centuries before the invention of synthetic application in modern times.

There are also canvas preservatives that can be used. These are a solvent based waterproofing process that requires the finish to be completely dry after it is applied for the full waterproofing effect to come into effect. You will know when it is dry because the sections this liquid were applied to will no longer be sticky to the touch. 

The seams of a tent are the places where the most water can penetrate even the best waterproofed tent. These seams can be made waterproof with a silicon sealant. The best type of this sealant should be the flexible type so the tent can be folded up and not damage the sealant in the seams.

Other words of advice includes that a canvas tent should always be dried before it is packed away. This will prevent the molds and mildew from growing and damaging the integrity of the canvas. Finally never wash your canvas tent in a machine. This will remove any of the waterproofing material it has and will cause your tent to leak unless it has the waterproofing material reapplied for it is used on your next excursion to the woods.