It’s all to easy to forget about looking after the canopy, but it could cost you dear – so here are some of the ways to keep your cover in top condition and get many more years out of it
Our tips to keep canopies in tip-top condition and get many more years out of them
The greatest cause of problems for all types of boat cover is ultra violet from the sun; add to that the effects of wind, rain and extremes of temperature and you realise how robust covers need to be.
The first step in treating a canopy is to ascertain what type of material it is made from. The two most common fabrics are PVC-coated polyester and acrylic canvas. If you’re unsure what type of fabric is on your boat, here are some tips to help you identify them along with the best treatment for each.
This is a fairly heavy fabric that tends to become stiff with age. It’s generally coated with a PVC layer that has a grained texture on the top side and a smooth surface underneath which is often silver/grey in colour. Some PVC has a canvas backing, although this isn’t ideal for boat covers.
PVC covers are, however, the lowest maintenance option; they can easily be cleaned using soapy water, a hosepipe or even a power-wash. They don’t require any special treatment and will never need re-waterproofing. However, the life of a PVC cover can be greatly extended with careful cleaning and use of a good PVC protector which provides a barrier against atmospheric pollutants and UV.
This lighterweight fabric is made from woven solution-dyed acrylic yarn and looks much like a traditional canvas material. It will retain its colour for many years and remain flexible throughout its lifetime, but it does require a little more care and maintenance.
To clean your canvas use a mild soap such as Dri-Pak Liquid Soap Flakes (don’t use detergents, they will damage the waterproof coating on the canvas). Make a soap solution using warm water (less than 100F/38C). Apply the soap solution with a soft brush or sponge paying attention to any persistent soiled areas. If you use a brush, be careful not to use it on the vinyl windows as they will scratch. The most common causes of staining on canvas are black/brown mildew and green algae/ moss.
HEAVY CLEANING FOR STUBBORN STAINS AND MILDEW
Acrylic fabrics do not promote mildew growth, however, mildew can grow on dirt and other foreign substances that are not removed from the fabric.
To clean stubborn stains:
Prepare a solution of 1 cup bleach and 1/4 cup of mild soap per gallon of clean water. Soak affected area in solution for 15 minutes. Blot the stain with a sponge or clean towel. This step should be avoided when cleaning the coated side (back side) of Sunbrella Plus, Supreme,
Rinse thoroughly to remove all soap residue. Air dry.
Note: Use caution when using bleach solution and be careful not to allow it onto other areas which may be adversely affected.
Many marine canvas products, including covers, canopies and cockpit cushions, use ‘Sunbrella’ brand fabrics. The Sunbrella website has detailed instructions on how to care for their canvas products which can be found at
sunbrella.com/cleaning. The same principles may be applied to any marine acrylic canvas.
THE ‘DREADED GREEN’
Another common complaint with canvas is the appearance of green staining, especially along bottom edges or anywhere that water can collect. This is caused by algae or moss growth and can be effectively banished by brushing the affected areas with white vinegar, allowing it to stand for half an hour before thoroughly rinsing.
Once your canvas is clean and dry, you will need to treat it to restore its water and stain repellency. This is simple using an aerosol which is sprayed directly on the clean canvas. As marine acrylic canvas is originally waterproofed using a fluorocarbon agent, it is not advisable to use silicon-based proofers because they will be rejected by the fluorocarbon-treated surface and be ineffective. Always re-proof with a fluorocarbon-based agent such as Holmenkol HiTech Proof or Ultramar.
CARING FOR CLEAR WINDOWS
The clear sections of the canopy are probably the most vulnerable elements. As the windows are made of vinyl, the sun’s UV rays will damage them over time making them discolour and eventually crack. Installing window covers will help greatly by shielding the windows from the sun when the boat isn’t in use. They can, though, become a little cumbersome and unsightly unless they are completely removable. When removing and storing any panels with windows, ensure the plastic is not folded and always try to loosely roll them to avoid permanent creases or cracks in the windows.
OTHER REGULAR MAINTENANCE
The other important components of a canopy are the zips and fastenings. Most marine zips are made from nylon which is easily damaged in the sun’s UV rays, so it’s important to make sure any protective canvas flaps cover the zips properly.
Clean and lubricate the zips and any mechanical fixings such as press studs (snaps), turn buttons and lift-the-dot fasteners. Keeping them lubricated will extend their life significantly and help prevent damage. Use a clear silicone spray such as Zip Lube, but be careful to keep the silicone off of the canvas. You can spray the silicone on a rag and then apply it to the zips and fasteners if necessary. Also, avoid petroleumbased products because both silicone and petroleum products are not compatible with most marine canvas coatings and materials.
In an ideal world, the canopy should be removed for dry storage during the winter months and replaced by a fitted tonneau cover or sheeted over with a cheap tarpaulin. Both options are fine, but whatever you do, avoid covering the canopy with a non-breathable sheet. This will cause moisture to be trapped both inside and on the canopy without any airflow; a guaranteed recipe for mildew and mould growth.
Roll canopies with windows
Clean under edges
Use white vinegar on green stains