GRP Cleaning and Polishing

General In Season Cleaning

Cleaning and polishing form an essential part of the maintenance regime for your boat. Neglecting this duty will not only affect it cosmetically but can cause various degrees of damage as growth of algae may compromise seals around hatches and windows, misshape and deteriorate canopies, leave nasty stains and cause persistent unpleasant odours.

Fiberglass boats, although being generally low maintenance, do require regular cleaning to prevent the growth of microorganisms and if kept on top of this is a relatively stress free procedure. The best place to start is a general wash down with a pressure washer and an environmentally friendly marine shampoo along the decks and hull; this can be done with the boat in or out of the water. To do this spray your boat with fresh water through the pressure washer (being careful around windows and hatches not to damage the seals and force water inside the boat), loosening any dirt and algae. Follow this by applying an environmentally friendly marine cleaner to all hard surfaces; in our yard we have been using the International range of cleaners and get good results from ‘Boat Shampoo’ which we dilute with warm water and apply with a soft brush.

Take a moment to think about how your decks drain, in most cases this will be from bow to stern, and work from the highest point (roofs, windscreens etc) down onto the deck making sure dirty water won’t run over and soil areas you have already cleaned. Rinse off the suds, repeat the process on the hull, and you’ll be left with a satisfying gleam. You can also use this technique to go over your canopy to remove loose stains such as bird mess and generally improve its appearance, however if your canopy is badly stained it is best to remove and clean with specific canopy cleaners (described later).

Heavy Cleaning and Stain Removal

For heavily soiled fiberglass boats, in cases which require more than just a marine shampoo, International have a ‘Super Cleaner’ in the same range. This is a stronger product, though it is applied in the same way as the ‘Boat Shampoo’, designed to cut through heavy dirt and scum. The major difference between the two products is that the ‘Boat Shampoo’ is designed not to wash off any wax coating or polish but to restore the shine, whereas the ‘Super Cleaner’ will require you to reapply wax or polish after it has been used, it is therefore best to use at the end of the season before you plan to reapply a finish.

A problem we see frequently with fiberglass boats is yellowing and rust stains, which ordinary marine cleaners just can’t tackle. If the fiberglass on your boat is affected by these you will need to use a specific stain removing gel. The ‘Stain Remover’ within the range is good quality and does not require any elbow grease. Make sure the area is clean and apply the stain remover, which is a thick gel, with a paint brush to specific areas or blemishes. Leave this for 10 minutes, rinse off with fresh water and admire the results. When using these harsher chemicals it’s a good idea to wear gloves as they can be irritating to skin and always be mindful of the environment.

Compound and Polishing

Compounding and polishing are an essential process in order protect the gelcoat and restore its appearance. Although some areas of your boat may be accessible for polishing whilst in the water, to fully compound and polish the hull will require the boat to be on dry land.

The first step in this process is to use an abrasive rubbing compound to remove any minor oxidation to the gelcoat as well as scratches and imperfections. Remember that compounding is an abrasive process and is used to remove imperfections and not to simply achieve a gleam, it is therefore important not to use this process too regularly but as the hull requires. Staying in the same range, the International ‘Liquid Rubbing’ is a typical rubbing compound which works by using an abrasive formula to remove a thin layer of gelcoat leaving a blemish free surface which can then be polished and sealed. The product requires a clean surface and it is very important to remove any traces of wax before you begin; the ‘Super Cleaner’ product will do this. Make sure the surface is dry and apply the compound much in the same way you would apply T-Cut to a car; using a clean cloth and circular motions. The ‘Liquid Rubbing’ can also be applied using an electric buffer (800-1000RPM) which can speed up the process. However take caution when applying compound with a machine as too much pressure can cause the formula to dry out and go lumpy as well as creating heat through friction that can damage the gelcoat. Once the compound is dry buff it off using a clean cloth or the electric buffer.

This process will leave a fresh layer of gelcoat that is smooth and shiny, however this gelcoat is exposed and it is important to apply a polish swiftly after compounding the hull. At this point you are faced with a couple of options as to how to finish the hull and you can base your decision on the quality of finish you would like, how much time you have to commit and also your budget. The ultimate finish will be achieved by using the International ‘Marine Polish’ followed by the ‘UV Wax Sealer’. The polish is an ultra-fine grade which gives a high gloss and lasting protection, whilst the wax sealer provides a hard shell finish which is UV, water and dirt resistant.

Alternatively, International offer a ‘Polish And Wax’ all in one formula which will give a shine to the gelcoat and a wax coating in one process. Application for each of these products is similar and they are suitable for use with an electric buffer (800-1000RPM) however once again technique is important when using this apparatus.

Further information on the International Boat Cleaner and Polish range can be seen here.

Polishing with a Machine

Using a machine to apply and buff polish and compound can speed up the process and save a lot of effort, however it is important to be properly equipped and prepared before you attempt to do so. Electric buffers invariably create heat through friction as they apply product to GRP, especially compound, and if the surface becomes too hot this can cause permanent and severe damage to the GRP. There are two types of machine generally used for compounding and polishing, orbital and rotary, and it is essential when choosing a machine that you select one with a range of different speeds.

The type of pad you use is also an important thing to get right and these come in a variety of materials. Most commonly you will find foam and wool pads, the foam pads will vary in their firmness suiting different pads to different processes. Ask your chandler for advice when choosing pads as different products will recommend different firmness or materials to be used, always follow the manufacturer’s guidelines. Technique is also important when using a machine, as mentioned it is essential to avoid excessive heat to build, this is prevented by not using too much pressure as you buff, keeping the machine constantly moving and checking regularly that the pad is not clogged with compound or polish. Be careful not to catch the gelcoat with the hard edge of the pad or machine as this can create a nasty gouge in the GRP. When working around objects such as cleats select a slow speed and be careful to avoid contact. If you catch a cleat or similar it is likely that you will shred your pad or worse cause injury to yourself.

 Canopy Care

An important exterior area that requires routine cleaning and maintenance, as mentioned earlier, is the canopy. To give your canopy a full clean and treatment it is usually necessary to remove it and lay it on a table on which it can be cleaned in sections. For vinyl canopies the process is fairly straight forward, you will require a stiff brush (I have found nail brushes work well) as well as a bucket of warm water and cleaner. There is a choice of specific vinyl cleaners on the market such as Yachticon’s ‘Vinyl Shampoo’ which you dilute in warm water and apply with a brush, however we have found that the environmentally friendly general cleaner ‘EVM’ works very well on vinyl canopies. ‘EVM’ comes in a spray and the method that works well is to get an area of the canopy slightly wet, spray on the ‘EVM’ and agitate with a stiff brush, dipping it into the warm water as you work.

Concentrate on areas where algae growth is prevelant such as zips and seams as well as giving a good brushing to the open areas. Rinse the green suds off with a hose and you are left with a much improved canopy.

Canvas canopies require a two-step process as it is important to renew the waterproofing after cleaning. The cleaning process is almost identical to that of a vinyl canopy, using a stiff brush with an appropriate canvas cleaner in the same manner. It is very important that once this process is finished and the canopy is dry, that you re-waterproof the canvas as the material can lose its water resistant properties over time and this will cause leaks, misshaping, puddling and sagging as well as mould and mildew to form and this really affects the overall appearance of a boat. The product we use for this is Fabsil’s ‘Universal Protector’ which is available in both a spray and liquid form. We prefer to use the liquid variety which is painted on with a brush and can be applied with the canopy on or off the boat. One thing to note is that if a canopy has not been treated in a while it will absorb a lot of the Fabsil and may require a few coats.

Once this has been finished it is essential to let the canopy dry, it mustn’t come into contact with moisture for at least six hours for the protection to properly dry into the material, therefore it is essential to either check the weather or make sure your boat is under cover.

Helpful Hints and Tips

So now that your boat is clean and looking like new here are just a few simple things to think about in order to maintain that satisfying gleam. Think about where your boat is moored, over hanging trees can become a nuisance as birds make a mess and leaves drop from above. Regardless of where your boat is located it is inevitable in the autumn that you boat will become covered in leaves at some point. This is a problem as the leaves become wet, stick to the boat and begin to decompose leaving a nasty brown stain. It is therefore a good idea to blow the leaves off at least once a week during the worst autumn period, alternatively you can use a hose with I high pressure nozzle to blast them off.