Keeping up Appearances - Part One

Although I have lived on a boat for many years, I still remember living in houses and all the associated work, such as mowing lawns, cleaning gutters, painting... The list seemed to be never-ending. The absolute freedom I was going to have when I moved onboard! No more gardens!

Well, somehow it didn't turn out like that. I exchanged one set of hassles for another - although the chores on a boat are more enjoyable... (That's what I keep telling myself, anyway.) But the result is the same: a boat, like a house, must be kept in order.

With this in mind, let's examine the maintenance required to keep a boat looking like new. I will discuss only fibreglass boats, as they are by far the commonest, although a lot of what I'll discuss will relate to other construction materials.

As with a car, cleaning a boat is the most frequent chore. I try to clean my boat monthly, as it's astonishing just how dirty it gets. The biggest culprit is air pollution. It's common to have a dew nearly every morning when living on the sea, and this dew trickles down the topsides, following the same path every day. This soon leaves those black streaks that all boat owners are familiar with, and which require monthly removal.

WHAT IS GELCOAT?
When a fibreglass boat is in the initial stages of manufacture, the mould is prepared by being buffed to a high finish before a release agent is applied. This is a special formulation that prevents resins from sticking to the mould.

Gelcoat, normally pigmented to the final colour of the boat, is then sprayed over this agent. When the boat is removed from the mould, the waxy lustre of the gelcoat is immediately evident, and when polished it comes up to a deep shine.

If only we could keep it that way forever! Unfortunately, over time Mother Nature will have her way, gradually reducing the gleaming, blemish-free surface to a dull, chalky finish. Sad, isn't it? Just as our bodies age, so does the finish on a fibreglass boat. However, there are steps we can take to prolong the life of the gelcoat.

Gelcoat is a mixture of specially formulated resins that differ from laminating resins in that they remain tacky when in contact with the air. Thus the surface of the gelcoat in contact with the mould cures to a hard, non-tacky surface because air is excluded, whereas the other side remains tacky. This tackiness will assist in binding the layer of glass and resin to the gelcoat when it's laid into the mould.

The thickness of the coat is much thicker than paint, typically between 0.25-0.50mm. Special additives are also incorporated into the gelcoat resins to prevent sagging. This stops it from draining down off the vertical surfaces of the mould. (Resins with these additives are termed 'thixotropic'.)

The application of the gelcoat into the mould requires a considerable amount of skill. If it's too thin, the layers of glass fibre will be visible through it. If it's too thick, it will be easily damaged because it doesn't have reinforcing glass fibre incorporated into it.

The shape of the mould also has a bearing on the serviceability of the gelcoat. Sharp, hard angles are extremely difficult to lay the fibreglass into, and as a consequence, voids behind the gelcoat can occur. When this happens, the outer surface only has to be knocked to shatter the gelcoat surface and reveal a deep crater that must be repaired by filling... But more on that later.

Another factor that affects the ageing process of the gelcoat is the experience and expertise of the boat manufacturer. The original waxy lustre of the vessel will be greatly extended by the selection of UV-stabilised resins, the correct pigment properties in the gelcoat, and the application of a thin surfacing tissue on the gelcoat before the main glass and resins are laid into the mould.

Finally, the colour is important, as some pigments, particularly red, are more affected by UV than others. Hulls with red pigment will not 'wear' as well as white, for instance. I've seen a boat whose gelcoat had powdered so badly due to ageing that when a hand was rubbed over the surface the hand came away covered in a fine talcum the same colour as the hull (although in this instance neglect was as much to blame as Mother Nature).

CRACKS AND STAINS
Fine cracks in the gelcoat are another common surface blemish. Resembling a spider's web, these can be the result of a heavy object striking the boat, but are more often the result of flexing of the moulding, which is usually caused by insufficient strength in that area. Dirt and grime then work their way into these cracks and cause fine spidery lines to appear.

If confronted with this problem, you need to stiffen the area to eliminate flexing before repairing. This can sometimes be a difficult job.

Such cracking often happens at the base of stanchions. People generally grab stanchions to help a boat dock and can exert an extraordinary force on the base of the stanchion, causing the glass to flex and star crazing to result. I doubt if the glass in this area can be beefed-up enough to prevent this. The only real cure is to beg people to push or hold the boat by the gunwale, but I have to admit this is a forlorn hope.

Gelcoat rarely stains, as polyester resins have excellent resistance to most things that would affect other surfaces - acids, in fact, are often used as a cleaning agent. Diesel fuel can produce an unsightly yellowing if left in contact with the surface for a long time, but good housekeeping around the fuel filler will mostly prevent this.

The worst stain I have seen occurred when an upmarket plastic shopping bag was left on a cabin top for a few hours in the sun. The bag was red - always the worst colour - and must have reacted with the gelcoat, because when the bag was removed, a red imprint was left on the cabin top. Various chemicals and experts were employed to remove the stain, but with no result. To the best of my knowledge, the stain is still there, although it did fade a little with time.

TIME TO WORK
Now we come to the part where work is involved. If you are wealthy, this probably means picking up the telephone and engaging your local boat detailer to bring the boat back to top condition. However, in most cases this work must be done by the PBO (poor boat owner).

Start by doing a thorough survey of the boat exterior above the water line. (I will leave underwater maintenance of fibreglass to a later article - and do I have some horror stories there!)

The first things to attack are any dings in the surface. If a blemish is the result of a void behind the gelcoat, this will need to be filled after first cleaning out the hole and then working back the gelcoat until the whole crater is exposed. If it's small, and in these instances it generally is, it can be filled with gelcoat pigmented to the same colour as the original. This can be purchased from any supplier of fibreglass products.

It's important to mention to the supplier at the time of purchase that the gelcoat is being used for repairing, not moulding. The reason is that, as mentioned previously, gelcoat will not cure in the presence of air. To overcome this, the supplier will add a small amount of wax to the resin. The wax will float to the surface and exclude air when it's mixed with the hardener, thus allowing the gelcoat to cure.

When applying the mix to the hole, make sure it is proud of the surface, as this allows it to be rubbed back when it has hardened. Use wet and dry abrasive paper - start with coarse and complete with extremely fine as a finish is put onto the repair. If the colour match between the repair and the original is good, an almost invisible restoration will result.

Star crazing of the gelcoat is a much more difficult job. The first thing is to ascertain the cause of the crazing - almost always flexing of the glass laminate, as discussed above - and try to eliminate it. Otherwise the crazing will simply return.

For example, I was once involved in repairing severe 'spider webs' that were evident around the corners of a hatch on a forward cabin trunk. This was an area that people sat and walked on, so it was evident that the moulding was not stiff enough to resist flexing, even though it had more than enough strength to support any normal weight.

The repair, in this case, involved removing the deckhead lining from the forward cabin and glassing in timber stiffening beams. Anyone who has done overhead fibreglassing will agree that it's a miserable job. However, in this case it was worth it, as the cabin top was made extremely stiff as a result.

Having removed the cause of the crazing, the initial repair could now proceed. The affected zone was given a thorough cleaning with acid to remove any grime, after which a solvent (such as Prepsol) was applied to eliminate any trace of wax and polish residue.

Next, the area was sanded with medium paper (600) to produce a surface free from any powdering of the gelcoat that could affect the repair. The worst of the cracks were gouged with a very fine tool such as a scriber (used to mark out on metal).

The affected surface was then screeded with a good quality filler (Probond or similar). Wet rubbing with wet and dry paper was next, going down through the grades until the last used was 800 grit.

In the case of this repair, it was possible to mask off the area to a line without the area being too big. This greatly assisted in blending the repaired surface with the original. A two-pack paint was applied, using one of the small disposable spray guns available today.

When the paint had cured, the surface was buffed using an electric buffer and buffing compound. These compounds are cast like large cakes of soap and given a number that indicates the grade of abrasive incorporated in it. The higher the number, the more abrasive the compound, G3 being the most commonly used for finishing.

Finally, a word of caution when using two-pack paints. Always use a top-quality respirator and follow the manufacturer's instructions regarding usage.

The result was worth the effort, as the unsightly crazing was seriously affecting the saleability of the boat. Potential purchasers with little knowledge of fibreglass could imagine all sorts of problems. In fact, one person asked the owner if it was osmosis, an affliction he had heard could cost thousands to repair. Osmosis is a subject for another day.

Rust staining around the exhaust and any other areas that have come in contact with metal can be removed with a 10% solution of hydrochloric acid and water. Remember that safety is paramount when using this chemical. Always use rubber gloves and eye protection, and if mixing this solution yourself, always add the acid to the water, never the water to the acid, as severe boiling could occur and spray the acid everywhere.

CUT AND POLISH
After repairing blemishes in the gelcoat, the next step is to restore the surface so that it matches the original as closely as possible. Polishing with a good quality fibreglass polish will do the trick if the gelcoat is in reasonably good condition, but you will need an electric buffer to do the job, as it's too big a task to do by hand. By the way, you must use a machine designed for polishing (2000rpm) because an angle grinder fitted with a buffing pad rotates too fast (6000rpm) and will burn the polish.

If the gelcoat has powdered off (that is, gone chalky), then the whole surface must be cut back using the cutting compound described previously. But remember, this involves removing a considerable amount of the gelcoat surface and can only be done once or twice in the life of the boat before wearing through will occur.

After cutting back, a good quality polish is applied and the whole area buffed. On boats where the gelcoat is in poor condition, the results of this treatment, particularly if done by an expert, can be truly astounding and can add thousands to the value of a boat. It's remarkable to see what a professional boat detailer can do to a vessel being prepared for sale.

BEYOND REPAIR?
What if the gelcoat is beyond repair? This typically occurs when the boat is around the 20 year-plus mark and is evidenced by serious chalkiness, colour fading and spider-like crazing with deep mould and grime penetration. In these cases, gelcoat yellowing around the bow area is usually evident, and although this can largely be removed with an acid wash when on the hardstand, it soon reappears.

There's nothing for it, I'm afraid, but a complete repaint. And for this you will need deep pockets. Most states these days do not allow the application of urethane paints in the open air. These paints must be applied in a specially designed facility, generally a totally enclosed shed with air filtration.

Virtually every piece of equipment must be removed from the outside of the boat and the whole surface sanded right back before spraying with two-pack paint. The process is involved, requires a large amount of skill and a lot of hard work. Leave it to the professionals.

Typically, repainting a 32ft boat costs $10,000-$20,000, with the results depending on the skill and dedication of the people involved. If you are contemplating this course for your boat, then I can only stress that you should first ascertain the expertise of the painters and the reputability of the company. Sadly, as in most industries, there are some shonks out there. Find out what paint they intend to use and do your own research, as the materials will be a big proportion of the cost.

Don't be put off by the enormity of it all, as constant attention will reduce the magnitude of the job and keep the love of your life looking as good as she did on the first day you got together. And anyway, it sure beats mowing the lawns!

Next month I'll have some real horror stories to tell you about - you guessed it - osmosis in fibreglass.