Boat cleaning inside and out – how to clean teak, fenders, and the waterline

Boat cleaning inside and out – how to clean teak, fenders, and the waterline

When your boat needs to be prepped and cleaned inside and out, as well as at the more challenging areas on the hull, it can sometimes be difficult to achieve good results. The fenders, waterline, and teak are among the more challenging areas when cleaning a boat since they can be severely affected by wind and weather, making them difficult to clean.

In this article, we focus on these three areas of boat cleaning, and show Biltema’s specialised boat care products that will give you great results when your boat needs to be prepped or cleaned during the season.

Fenders are crucial pieces of equipment

Boat fenders are at the frontline and protect your boat when you dock, as well as from weather and wind.

The fenders have a very visible position on the boat, which contributes to the appearance of the boat. They protect the boat and therefore often end up with wear marks and deposits. This means it’s important to clean the fenders regularly. Here are some great tips for cleaning fenders:

  • Clean the fenders as soon as possible to make sure dirt does not stick.
  • Apply fender cleaner, preferably with a microfibre cloth, and rub off the dirt in a circular motion.
  • Cleaning may need to be repeated in especially hard-to-reach areas.
  • If there are very strong deposits that have worked their way deep into the material, you can try polish them off with Marine Rubbing.
  • After fender cleaning, we recommended protecting the surface with wax to make it difficult for new dirt to stick.

Cleaning and restoring boat teak

Teak is a wood species frequently used on a variety of boat types, and it has been associated with sailing and boating for many years. But your teak planks, teak decking, and teak furniture live a tough life aboard the boat. Therefore, it is necessary to maintain and clean the teak material on board.

Cleaning your teak deck thoroughly and frequently is profitable for you in the long run, since installing a new teak deck is a rather costly project.

In Biltema’s boat care range, you will find teak cleaners and teak restorers, which are two different products that can clean your teak deck or other teak fittings and breathe new life into them.

Teak cleaner is an alkaline cleaning agent that cleans deeply in wood that has been infested, such as by algae coatings. Depending on the extent of the infestation, freshwater solutions from 1:1 to 1:3 can be used. Use a brush to apply teak cleaner to the dry wood surface so that it can be brushed into the surface to loosen the dirt. Allow it to work for 2-3 minutes, then brush in the direction of the grain to get a deep cleaning effect. It is important that you do not leave the teak cleaner on for too long, so you should therefore rinse the cleaned area with fresh water within 10 minutes. It is also important to prevent the undiluted teak cleaner from dripping, as this can cause stains. Teak cleaner is approved for use with the most commonly used sealants on the market, but if you have the slightest doubt, test it on a small area first, before treating larger areas of the boat.

The cleaned area should then be treated with teak restorer, which will help restore your teak to its original light appearance. Apply the teak restorer using a sponge, brush, or swab. Allow the product to work for about five minutes and then rinse with water.

To get the best protection for your teak, you should finish the work by applying a suitable wood oil or varnish as a final coat.


Teak Cleaner and Teak Brightener - Teak Cleaner and Teak Brightener are two effective products that help keep your teak clean and looking fresh on board.

Waterline cleaning – clean the waterline on your boat

The waterline on a boat is a difficult place to clean, and it is an area of the hull that often gets dirty and is more exposed to dirt than the rest of the boat.

Waterline Cleaner from Biltema is a specially designed product to clean the area at the waterline. The product contains oxalic acid, which is very effective against discoloration.

Apply Waterline Cleaner to gelcoat and painted surfaces, then allow to work for about five minutes. Then rinse with clean water. For severely infested areas, the treatment can be repeated until you are satisfied.

If the area requires extra polishing, an option is to use Marine Rubbing and then polish the area clean. Keep in mind that regardless of whether you use Waterline Cleaner or Marine Rubbing, the surface must subsequently be protected with boat wax.

Bonus info: We also have boat canopy/sprayhood cleaner for washing stronger textiles such as the boat's canopy. This is also a part of the boat that is very exposed to wind and weather. Do you want to protect your sprayhood a little extra by impregnating the canopy on the boat? Then you should choose a boat tarpaulin impregnation off the shelf.

Can’t find the product you’re looking for in our article?
Explore our full hull care range in the link.

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