Do All Fiberglass Boats Have Gelcoat | Answered

Yes, all fiberglass boats are coated with Gelcoat. Gelcoat is a thin, clear coat that is applied to the fiberglass surface and helps to protect it from UV damage, scratches, and other wear and tear. It also helps to give the boat a polished look.

Gelcoat is made by mixing pigments and gel-type materials, such as vinyl esters and styrene with a catalyst. The mixture is then sprayed onto the surface of the fiberglass and allowed to cure and harden. Most manufacturers will create their own secret chemical formula that contains various amounts of each component, depending on how thick they want the coating to be.

Gelcoat is known for its beautiful appearance and durability when applied to fiberglass surfaces, however, it can become worn or damaged over time when subjected to sunlight, humidity, saltwater, road debris, marring from keys or other objects being placed on the deck of the boat.

What Is Actually a Gelcoat?

Gelcoat is a resin matrix containing a high percentage of solids and pigments suspended in a liquid. It hardens by absorbing water from the atmosphere and curing, initially through an exothermic reaction of amine groups with atmospheric moisture to form hydrogen bonding followed by polymerization.

Gelcoats are formulated with several additives such as rosins, polyamides, and ultraviolet light absorbers to alter the specific gravity, color, viscosity, hardness, abrasion resistance, and other properties.

Gelcoat is manufactured with two main components: resin & hardener. Resin type refers to what polymer is used in making Gelcoat while hardener type refers to how it’s mixed together to make Gelcoat.

Gelcoat is specifically formulated for water-resistant and stopping UV rays from penetrating through the hull. Many Gelcoat formulations are formulated with additives such as antioxidants and ultraviolet stabilizers to increase resistance to degradation by UV light, which causes “chalking” (when the color of Gelcoat fades) and loss of strength.

Why We Use Gelcoat on Fiberglass Boats

Gelcoat is a clear resin and hardener mixture that is brushed onto the surface of the fiberglass. This external layer protects and provides color to the interior layers of laminated glass.

A Gelcoat covering will ensure your boat’s hull is intrusion-free and add a glossy appearance. Gelcoat is also used in fiberglass pools to provide the water with clarity and protection from UV rays. Everyone wants their boat to look new for as long as possible, making regular top-up coats of Gelcoat important.

A protective layer of Gelcoat will save your fiberglass boat from harmful UV rays, oxidation, and water damage. That’s why you should consider Gelcoat as an effective way to give your boat the protection it deserves.

One needs to rework on Gelcoat if it damages, fades, or becomes cloudy. The best way to avoid this problem is regularly to coat your boat in Gelcoat.

When to Use Gelcoat on Your Fiberglass Boat?

Modern fiberglass boats come with a protective Gelcoat covering already applied to the surface. However, when you buy a boat make sure you ask your boat dealer whether the Gelcoat still looks fresh and if any touch-ups have been done.

If you decide to buy a used boat make sure to ask the previous owner for a maintenance logbook. If they have one, then you can check through it and see whether or not they regularly maintained their boat with Gelcoat.

If the seller is unable to provide you with this information, then it might be a better option to look elsewhere as using Gelcoat requires regular maintenance – which is the responsibility of the seller.

If your boat is old enough to have faded or damaged Gelcoat, then you may need to reapply this protective coating. If yes, then all you have to do is clean the surface thoroughly with soap and water.

How Long Does Gelcoat Last?

If your boat is well-maintained, the Gelcoat layer will last for many years. If you love to go sailing on a regular basis, then you might need to re-touch up your boat’s Gelcoat every year or so.

However, just because you have not used your boat for a long time does not mean that the Gelcoat layer has worn or peeled off. It is also not necessary to reapply the Gelcoat if you have spent a few months away from the water.

One should apply Gelcoat to their boat every so often after it has been out of the water for a month or two, and especially before winter arrives. This encourages better protection and keeps the boat looking new for longer.

Is Fiberglass Waterproof without Gelcoat?

Fiberglass becomes waterproof when the resin is added to it. There are several layers on the fiberglass, starting with a base coat of resin on which the fibers are added. The final layer is the Gelcoat, which is where the color and shine come from.

Fiberglass does not become waterproof without Gelcoat on it, though many people refer to any sort of fiberglass boat as being waterproof.

If you have a fiberglass boat without Gelcoat, then it will not protect the inside from water damage. Leaving your boat in the water for long periods of time will lead to oxidation and may cause the materials used to become brittle.

How Do You Know When Your Boat Needs Gelcoat?

It is often quite easy to tell when a fiberglass boat needs Gelcoat. Look at the hull and check for any cracks, splinters, or chips in the fibers.

If you see any such signs of damage, then it is time for a touch-up of your Gelcoat. Fading and oxidization are also sure signs that it is time to reapply your Gelcoat layer on your boat.

If you notice that the Gelcoat has worn off of your fiberglass boat, then this means it is time to reapply the protective coating and bring back its original color and shine.

The best way for you to determine whether or not your boat needs Gelcoat is to look at your hull carefully and note down any areas which may need some touch-up work. If you only see one or two minor spots that could be reworked, then it might not be necessary to reapply your entire Gelcoat layer.

How to Maintain Gelcoat on Fiberglass Boats?

Maintaining your fiberglass Gelcoat is important to keep your boat looking new. You can clean and polish your Gelcoat to keep it looking its best. To clean your Gelcoat, use a soft cloth and mild soap or detergent.

Be sure to rinse the boat thoroughly afterward. You can polish your Gelcoat with a polishing compound or wax to protect it from the sun and UV rays.

To maintain the color and luster of your Gelcoat, you should wax it several times a year. Waxing excesses dirt and grime and keeps it from settling into the surface. It is also important to note that not all fiberglass boats have Gelcoat.

Some have Gelcoat, which is basically a layer of Gelcoat with sheer or translucent colors, while others have a solid color.

How to Keep Gelcoat from Oxidizing?

Oxidization can ruin the look of your boat, so here are a few tips you can use to keep it from happening:

– Try not to leave your boat in the water for too long. This is particularly important if you have a solid color rather than Gelcoat on your boat. Leave your boat out of the water during wintertime especially

– Wax your boat often to prevent oxidation.

-Wash your boat with a soft cloth every so often, using only mild soap or detergent. Avoid chemicals that could potentially damage the surface of your fiberglass boat.

Before you launch your watercraft again, especially during the wintertime, be sure to apply fresh coats of wax on your Gelcoat. This will keep it looking shiny and new while avoiding the effects of oxidation.

There are several different types of fiberglass boats, but they all have one thing in common: They need to be protected with a layer of protective Gelcoat. If your boat does not have any Gelcoat on its surface, then you should consider reapplying it.

If you have doubts about whether your boat needs Gelcoat or not, be sure to look at the fiberglass surface carefully and note any areas of damage that could use touch-ups before giving it a full reapplication.

How to Remove Stains from Gelcoat?

Gelcoat is very durable and can resist damage well. It also resists mildew, mold, and other growths. However, if the conditions are right for such things to take root on your boat’s surface, then they could still grow.

This is true whether or not your boat has a Gelcoat layer because it can be penetrated by stains and growths when damage to the fiberglass occurs. When this happens, you will have to remove these blemishes from your Gelcoat in order to have a clean, smooth surface again. 

In cases where you have smallish stains on your boat, you can try buffing them out. Buff the area with a soft cloth to see if the stain is removable. If it does not disappear entirely after you have buffed, then move on to the next step.

If the stain remains even after you have tried to remove it via brushing and polishing, you can use a Gelcoat solvent. These are available in most boating supply stores. Some have to be used along with a special pad while others only require the use of your hand. Follow the instructions for whatever type of solvent you decide on using, and remember that it is not advisable to rub too hard because this could damage the fiberglass.

Finally, if the blemish still remains after you have used a solvent, then it might be time to apply a new layer of Gelcoat. This will ensure that you do not get any future stains and remove the blemishes already there so your boat will look as good as new.


Gelcoat is a clear resin and hardener mixture that is brushed onto the surface of the fiberglass. This external layer protects and provides color to the interior layers of laminated glass. A Gelcoat covering will ensure your boat’s hull is intrusion-free and add a glossy appearance. Gelcoat also has UV protection which can save your fiberglass boat from harmful UV rays, oxidation, and water damage. That’s why you should consider Gelcoat as an effective way to give your boat the protection it deserves.