How Long Do Fiberglass Boats Last? 3 Aging Factors (+ Basic Care)

In Boating by Morten Storgaard

Fiberglass is currently the most common material used to craft small recreational boats and other watercraft.

Chances are if you have purchased a recreational boat it is either made of fiberglass or plastic.

In this article, we will look at how long fiberglass boats last and the factors that impact the durability of fiberglass boats.

How Long Do Fiberglass Boats Typically last?

Fiberglass boats can be operated for up to fifty years or more. Fiberglass is very durable and with proper maintenance and care, fiberglass boats can last for many decades.

Fiberglass itself will not break down but instead will break down due to outside factors.

Some factors that will affect break down are:

  • Exposure to UV rays
  • Fatigue from movement
  • Water saturation
  • Salt from seawater.

Too much UV rays can cause the fiberglass to become more brittle. Because most boating happens during sunny weather conditions, this is a highly probably issue.

Water saturation can cause a breakdown between the fiberglass and the resin. This is most often caused by a formation of acid with the water and products hidden in the fiberglass.

Salt from salt water can move between the fiberglass and become deposited in the larger porous areas of the fiberglass. This causes the salt to put pressure on the fiberglass.

One final issue could be poor production at the beginning of the boat’s life. This is hard to combat, and you will want to ensure you purchase a high-quality boat.

One of the biggest issues you will encounter with your fiberglass boat are the other components. Your fiberglass is much more likely to last than your other structural, engine, and electrical components.

3 Factors That Impact The Durability Of Fiberglass Boats

So, what if you already have a fiberglass boat? Or you are about to buy a used fiberglass boat?

You’re probably thinking: what should I look out for?

The main things you want to look for in your fiberglass are:

  • Small cracks
  • Fatigue
  • Water damage

1) Small Cracks

To find aging breakdown you will want to look for microscopic cracks.

At first, they might seem minor, almost hairline. These cracks should not be ignored as they can get bigger with time. The bigger the cracks, the more pressure applied to the structure and integrity of the fiberglass.

This break in the integrity of the fiberglass can further compromise the structure of your vessel. For this reason, fiberglass boat owners need to constantly monitor their boat for cracks.

When cracks are found, they need to be dealt with and filled in.

2) Fatigue

Fiberglass can also experience fatigue.

Vibration and impact on the fiberglass can cause stress and fatigue. Repetitive waves, large equipment, and other activities can cause strain on the fiberglass.

After a certain amount of time, fiberglass can also get worn down. Without proper care, the fiberglass can become weak and brittle.

3) Water Damage

You need to ensure your fiberglass is not experiencing water damage.

While the resin itself is waterproof, if water gets in it can corrode the fiberglass. Eventually, after enough water is absorbed the damage will apply more and more pressure which can cause wear, blistering, and cracking.

The part of the boat that is most susceptible to this damage is the part of the hull that is below the waterline.

The last thing to look out for is heat and sun damage.

With enough heat and UV rays, the fiberglass in the hull can become rigid and brittle. This can even cause warping.

One major issue with a fiberglass hull is that warping or major damage to the fiberglass itself can be very challenging and expensive to repair.

As previously expressed, if you own a boat that is older your main issue is most likely not in your fiberglass. That doesn’t mean that you should not maintenance and monitor your fiberglass. Vigilance, maintenance, and preventative care is the best way to maintain the structural integrity of your fiberglass.

How To Prolong The Life Of Fiberglass Boats

Some people will try to tell you that your fiberglass “does not need maintenance”.

This is not true.

Compared to other types of boats, especially wooden boats, fiberglass is much less maintenance. This does not mean that there is no maintenance involved, and you must keep up with it.

Most importantly when attempting to maintain your boat, you need to protect the bottom that is constantly exposed to water.

If your boat is left in the water for even a few days, you will want to attempt to protect it from algae and other growth. To prevent this there are certain protectants and poison paints you can apply.

You will want to ensure whatever growth repellent you purchase works for the area and body of water you plan on having your boat in. Before application, you will want to make sure to properly sand or otherwise prepare your fiberglass.

The area between the railing and the waterline need to have regular maintenance done as well because this part of your boat takes on most of the waves, spray, and sun. Without proper care, this area will fade, oxidize, and get hazy. To combat this wear, you need to make sure you keep up the wax on your boat.

If waxing becomes a hassle you can get a buffer. This will enhance the process and make it easier to complete.

The deck of a boat also sees a lot of wear. This comes from sun, dirt, grime, spills, and other general wear and tear. The main way to combat this is regular washings and a good stiff brush.

Be sure to never wash a “non-slip” area with wax. This is highly important on the deck where people walk. Safety should always be your first priority.

Besides this maintenance, you will want to maintain cleanliness on all other aspects of your boat. This will help to keep the condition pristine and avoid aging and wear.

Finally, no matter what type of boat you own, you will want to properly maintain the engine. You want to make sure you maintain your boat engine constantly.

This is true if you use your fiberglass boat every day or only occasionally. If you only use your boat occasionally, you will still want to maintain the engine as if you use it regularly.

Maintaining your boat engine is like maintaining your vehicle engine. You will want to make sure it is properly oiled, fueled, and the boat battery is charged.

Similar to a car, keeping a boat’s radio or lights on for a long time can drain a battery, even kill it.

How To Spot Aging Signs On Used Fiberglass Boats

When buying an old fiberglass boat, especially a “fixer-upper” there are some things to keep in mind.

Unlike wooden boats, fiberglass boats are more difficult to repair or restore.

Restoring a fiberglass hull can be almost impossible depending on the wear accrued. Because these hulls are made all at once, patching them is your only option if the problem is that simple.

Wooden boats are more maintenance and more difficult to maintain, but they do allow for the replacement of parts.

When purchasing a used fiberglass boat, you will want to look out for the signs listed above. You will need to know if you are looking at any structural issues.

Make sure to check for cracks, fading, wear, growth, or damage. Look at the high-stress areas for cracks, wear down, or other signs of tear.

The pressure created in the fiberglass can cause issues for you later.

As well as fiberglass wear you will want to make sure that your hull is not chipped, blistered, or starting to flex.

Stress on a fiberglass hull can cause flexing as degradation occurs. This can cause major cracks and severe hull issues.

Issues found with a boat can be fixed but based on the extremity of the issue and your experience you should look for a professional opinion on maintenance and damage restoration. This is important before you buy. Taking on too many issues may quickly make your new boat purchase a headache you never wanted and were not prepared for.

If everything is intact with the boat, and you do not see any cracks, warping, mechanical failure or other issues it would be safe to purchase the used fiberglass boat.

If you keep up with the proper maintenance, you used an older fiberglass boat could last you many years to come.

Why Do Fiberglass Last So Long?

Fiberglass is a form of plastic that is reinforced using glass fiber. The glass fiber is usually woven into a fabric. This makes the fiberglass superior when it comes to durability.

Fiberglass material is lightweight, extremely durable, and less brittle than standard glass or plastic.

Fiberglass can be easily molded and is often used to make more complex shapes. Standard uses for fiberglass are boats, aircrafts, bathtubs, etc.

For a boat to be considered a fiberglass boat the hull, deck, liner, and even large parts of the console are made from fiberglass.

To use fiberglass to construct a boat you first use a gel coat, apply a fiberglass cloth, and then add resin overtop.

Before fiberglass, boats were constructed from bark, wood, animal skin, iron, or steel. Larger ships today are still constructed from aluminum or steel while smaller recreational boats are made from fiberglass or plastic.

Fiberglass boat construction was experimented with as early as the late 1930s and is the main manufacturing method used today.