When water soaks into your boat cover instead of beading off it, the water-repellent finish is worn out. That is normal after one or two seasons outdoors. Fortunately you can restore it yourself at home in three steps: cleaning, stain removal and re-proofing. Below you will read exactly how this works and which products to use.
Why does my boat cover no longer repel water?
Boat covers are made of synthetic textile, usually polyester or acrylic. New material repels water because the fibres are treated with a water-repellent finish. Over time that treatment breaks down. Dirt, sunlight and use speed up the process.
You will notice it straight away: water no longer forms droplets but soaks into the fabric. The cover then feels heavy and dries more slowly. This does not mean the material is ruined. It means it is time for maintenance.
How do I make my boat cover water-repellent again?
Always follow this order. Do not skip a step, because a protective product only works well on a clean, dry cover.
Step 1: cleaning
Start by removing surface dirt. Use Sprayhood & Tent Shampoo for this. This cleaner is developed for synthetic boat covers and does not attack the material. Work the shampoo in with a soft brush, rinse thoroughly with water and let the cover dry completely.
Do not use household cleaning products. They can damage the fabric and affect the fibres, which makes a water-repellent product bond less well afterwards.
Step 2: removing stains (only if needed)
Are there still stubborn stains or deeply ingrained dirt after cleaning? Treat those specifically with Fabric Power Cleaner. Apply this product only to the affected areas and let it work in for a maximum of 15 minutes. Then rinse well and let the cover dry again.
Do not use Fabric Power Cleaner over the entire surface. Targeted application gives the best result.
Step 3: protecting
Once the cover is clean and dry, you can impregnate it. For a synthetic boat cover, use Sprayhood & Tent Protector. Spray the product evenly over the entire surface. The protector restores water repellency and helps new dirt stick less easily.
After applying, let the cover dry well, preferably outdoors. Then check whether water beads off again. If it does, the treatment has succeeded.
Which product do I use to impregnate a boat cover?
For most boat covers you use Sprayhood & Tent Protector. This product is intended for synthetic outdoor textile such as polyester and acrylic.
Do you have a cover made of real cotton or canvas? Then use Canvas & Cotton Protector. This product is specially developed for natural fibres and keeps the material breathable.
Not sure what material your cover is made of? Check the manufacturer's documentation or ask the sailmaker who made your cover. When in doubt, and if your cover looks synthetic, choose the Sprayhood & Tent Protector.
All Ultramar maintenance products are PFAS-free.
What should I do if my boat cover absorbs water instead of repelling it?
First check whether the cover is dirty. Impregnating a dirty cover makes little sense, because dirt blocks the bonding of the protective product. Always clean the cover first with Sprayhood & Tent Shampoo, remove any stains with Fabric Power Cleaner and only then apply the Sprayhood & Tent Protector.
Also check how long ago you last treated the cover. With intensive use or a lot of sun exposure it is wise to re-proof every season.
How long does the water-repellent treatment last?
That depends on how often the cover is used, how long it is exposed to sun and rain, and how well it is maintained. In many cases an annual treatment is enough. For heavy seasons or intensive use, you can consider applying an extra layer halfway through the season.
Frequently asked questions
Can I wash my boat cover in the washing machine?
We advise against it. A washing machine can damage the structure of the fabric and affect the waterproofing of the seams. Prefer to use Sprayhood & Tent Shampoo with a brush and water.
Do I have to take the cover off the boat to treat it?
That is not necessary. You can clean and impregnate the cover on the boat. Just make sure you reach all surfaces properly and that the cover can dry well after treatment.
Can I also use the Sprayhood & Tent Protector on the plastic windows in my boat cover?
No. Always treat plastic or transparent windows separately with Plastic Window Cleaner and Plastic Window Protector. Never use a fabric product on plastic windows.
How do I know whether the impregnation has worked properly?
After drying, drip a little water onto the cover. If the water clusters together and beads off, the treatment has succeeded. If the water soaks into the fabric, the cover may not be fully dry yet or the impregnation needs more time to take effect.
