gelcoat restoration on yacht

Gelcoat is a kind of epoxy resin. It is what provides the high-quality “glass-like” finish to fiber-glass and other composite materials used in building the hulls of boats and yachts.

Motor yacht hulls are created in molds. During the hull manufacturing process, gelcoat is meticulously sprayed onto the inside of a “female mold.” Then, a fiberglass laminate is applied over this; after that the core, and so on and so on, in a layering process. Since it is applied to the inner walls of the mold first, when the composite hull comes out of the mold, the Gelcoat is the shiny pigmented “skin” on the outside surface of your yacht.

The gelcoat provides the pigmented outer surface of the yacht as well as a smooth, attractive yet durable finish. Some inside surfaces of a yacht may also be “painted” with Gelcoat during or after the manufacturing process. For this, and other reasons, Gelcoat is sometimes confused with paint. But, Gelcoat is not a paint.

Gelcoat is basically a pigmented fiberglass resin. As mentioned above, in some small inner surface areas, it may be “painted on” like you might coat resin on a wooden table. But, it is not designed to be used that way, or applied like paint over large areas with sprayers after they are completed. Unlike paint, or other marine resins, gelcoat is really designed to be applied during the composite molding process.

Gelcoat application

Gelcoat Being Applied to a Deck Mold

Cracks in Your Gelcoat and Other Problems

While gelcoat is designed to create an aesthetic surface, it can crack due to exposure to weather, dents, dings, and other surface damage. Applying gelcoat to the molds is not easy, and if it is done incorrectly, it can come out of the molds not cured properly and therefore be more prone to cracking. Even when gelcoat is applied properly there are areas such as around hardware, and complex surfaces where it can also tend to crack due to stress.

Even if you gelcoat is free from cracking, it can get dull due to oxidation, and make your boat appear to be old and lifeless. Removing oxidation, and returning the luster to the gelcoat is usually part of any detailing process.

Repairing Gelcoat

Regardless of the reason why your gelcoat may be cracking or showing other imperfections, it needs to be repaired by skilled gelcoat technicians. However, before being repaired it is important to determine the source of the cracking. If it is obviously surface damage, such as from the impact with a dock, or other object, the repairs are pretty straight forward. But, if the cracking is the result of an underlying structural problem, or from a leak, merely fixing the outside gelcoat, without finding and addressing that problem first amounts to just putting on a patch, that will only become damaged again.

cracking gelcoat

Cracks in Gelcoat

It is also important that your gelcoat repair technicians are skilled enough to determine the depth of the cracking. Remember how we described how gelcoat is first applied in a multi-layer sandwich. You need to determine how deeply the cracks have penetrated, if at all, beyond the gelcoat layer. If the cracking has extended down into the laminate, then the problem, and its repair, are far more complex and far less merely aesthetic.

But, usually, gelcoat cracks are simply a cosmetic problem, and usually do not present any safety or structural issues to the boat. However, on a luxury motor yacht, what is on the outside is equally as important as the inside.

Even barely noticeable lines or cracks in your gelcoat, will want to be taken care of quickly, before they can damage the value and aesthetic appeal of your motor yacht.


Fixing Damaged Yacht Hull

Repairing Gelcoat


Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (954) 900-9968.