Canvas Care – Part One

For those who are looking at buying or who already own some sort of a recreational Vehicle, you will come across canvas somewhere, somehow. It’s a material that has been used for many many years, in truck tarps, touring tents, camper trailers and even in some caravans, the list goes on with its applications in the great Australian way of life outdoors.

canvas care
canvas care

To the average person the world of Canvas is something they probably never really have thought about, its there, you use it, you don’t touch the sides in the rain and hopefully you keep it clean, what more is there to know other? Well over the next few issues I will try to enlighten you on the different types of canvas and how to care for it. Treated right, quality canvas should give the owner many years of faithful service. The first thing to know is that Canvas has come a long way in the last 5-7 years. The canvas today is vastly different to the canvas when you were a kid.

There are many different types of canvas on the market, some which are all cotton, some which are all polyester and some a mixture of the both. It’s important to understand the differences in canvas and their different applications. The importance is whether you’re using the right canvas for the right situation, and if you are finding difficulties in use, then this article may help you know why,

100% All Cotton Canvas, is not used much in the RV industry any more, it’s history lies in the times before polyester came on to the market. Cotton canvas has a number of advantages

  • Firstly, it’s a fabric that breathes, this allows the canvas to be used in applications such as tents etc
  • Secondly, cotton canvas helps the water proofing process because the cotton soaks up moisture or water

Unfortunately 100% cotton canvas also has some disadvantages, the main one being that 100% all cotton does not stand up to the harsh elements of the Australian weather and the life expectancy is shortened due to the breakdown of the fabric. You may still see all cotton in swags, where they’re not exposed to the elements for great lengths of time.

100% All Polyester canvas is used in sunblinds & shades and outdoor structures. Polyester gives the fabric its strength and due to its all man made content its not susceptible to staining and mould. However it’s not a breathable fabric like the cotton or poly/cotton blends and using this type of fabric in a camper is like sleeping inside a plastic bag!

The Polyester & cotton canvas used in campers these days are usually a mixture of 50/50 poly/cotton blend or 65/35 poly/cotton blends. The polyester is for the strength and durability and the cotton is for the waterproofing and breathing aspect. The cotton will take up water, swell and sit in place. This combined with the waterproofing; waxing agents etc they place on their canvas makes it an ideal breathable waterproof structure if used correctly in the manufacturing of outdoor mobile RV vehicles, i.e. camper trailers etc.

If you pierce a poly/cotton canvas with a sewing needle, the cotton will move back in to place around the thread once it has been taken up with water, the pure polyester canvas wont.

Much has been made of the weight of canvas with many manufacturers claiming different weights are better for different applications. To the normal person this is again confusing, so I’m going to focus now on the poly/cotton canvas and the 2 main weights of canvas used in the RV Industry – 15oz and 11oz.

15oz canvas is usually 50/50 poly/cotton blend; this weight of canvas has been used in the industry for many years. It is made by one thick single strand of canvas woven one way, one woven the other, then proofed by a substance that may contain rot proofing agents, UV stabilizers, water proofing agents and an acrylic binder. The material is usually placed in a bath of this mixture, the excess squeezed out and placed through a roller so the pigment proofing process penetrates the fibre. Once this occurs it is either dried or cured by rolling it over a hot roller twice or by a gas fired drying process, almost like a convection oven, depending on who the manufacturer is.

As with most things in this fast moving world we live in Technology has now caught up even with canvas…. The new breed of canvas is 10 or 11oz poly/cotton canvas. This starts life as an 8oz base cloth but once the pigment proofing process occurs it then becomes a 10 or 11oz. There are 2 manufacturers in Australia who use the base cloth as a double warp, double weft. That’s is two strands woven one-way, two strands woven the other. This makes the end product being tightly woven, just as strong and durable as the 15oz, just as waterproof as the 15oz but really half the weight. This particular cloth knocks on the head the “ heavier is better” belief, because its not necessarily so!

In the old days the heavier the canvas the better the wearing capabilities but having this knowledge now may prompt some of the old school to accept that its really not necessary to use heavier canvas, even on the roofs, when you have a cloth that has all the same capabilities as the 15oz but you don’t have to break your back lifting or working with it.

Now you need to go back a few steps in this article, the part where I was describing the poly/cotton canvas and how it behaves. If you have an RV with new canvas work, and it is a poly cotton blend, you will need to “weather” it before heading out on your trip. Despite the process the manufacturers put their canvas through with pigment proofing process, water proofing etc, this cloth then comes to us canvas manufacturers to turn in to the end use in various shapes and forms. We cut and sew the canvas, and in this process we will puncture the cloth with needles and join cloth-to-cloth, cloth to zips and cloth to binding etc.

Once this has been done and the final product produced, the canvas needs to be wet down or proofed, once or twice for the cotton component to take up the water swell and sit in to place. This is especially important around the areas that have been penetrated by a needle. Any good canvas manufacturer of outdoor products will also use lock seams in areas of extreme exposure to the elements to minimise the risk of leakage.

All of these outdoor poly/cotton canvas products should have quality poly/cotton threads used as well, this again helps with the water proofing process when you have penetrated the material, even a zip!

In rounding up this article on canvas, there are 3 manufacturers of canvas in Australia, Wax Converters, Bradmill and Defab. Two of these manufacture bring the base cloth in and then do the proofing process as described above, the other weaves proofs the base cloth here. There is some very fine canvas produced here in Australia, suited to our particular climate and temperatures, combined with the strength and durability and waterproofing needed to help us enjoy the great out doors in a very comfortable manner.