When choosing your epoxy, it is important to take note of the material you are going to be working with. Marine-grade epoxy is what you will need if your project is going to be exposed to or submerged in water. This could include things like boat repairs, repairing of pipes, amongst other projects. The various epoxies available each have their own features, which in turn have pros and cons attached to it. So, by doing a bit of research and getting informed, you will be able to choose the correct marine epoxy resins suitable to your needs.




Marine Epoxy Resins, what is it?

As mentioned, marine epoxy resins are needed for those projects that are going to be constantly exposed to water. Think of a boat hull and underwater pipes, which is submerged in water. You need epoxy resin that is durable, versatile, and reliable, especially if it is going to be exposed to a harsher environment. Once the marine epoxy resin has fully cured, it becomes waterproof and offers great strength.



Choosing the correct Marine Epoxy Resin

When the time comes to buy your marine grade epoxy resin, you need to consider a few things. This type of product can be purchased as a thick liquid or paste. For the thick liquid, you can get a filler powder, which allows you to thicken when needed. Otherwise, the thick past resin includes a hardener when you buy it.

Helping you make the right choice you need to consider the following:

  • You need to choose the epoxy that is best suited for the project you are working on.
  • Always check the shelf-life, an epoxy resin product should be used according to the recommended date. You might encounter problems if the use-by date has expired.
  • A liquid epoxy along with a filler is a better choice, as these products are all ready to go when required, especially in an emergency.
  • Make sure to follow instructions when it comes to mixing the resin and hardener. Take note of the time you have to work with the epoxy resin. Remember, take note of any requirements related to temperature as well as humidity.
  • Do some research, you will come across polyester resin, which is considered a resin, but it does not have the durability and strength the epoxy resin has.
  • Always wear protective wear when working with epoxies such as gloves and eye goggles. Have ready some mixing sticks and containers for your epoxy.

marine epoxy resins



Marine Epoxy Resin Applications

All epoxy resins are similar and have bonding, coating, sealing as well as water-resistant properties. This makes epoxy resin great for a variety of applications. The different types of resin you get are your tabletop resins, art resins and, of course, the clear marine epoxy resin. The marine-grade epoxy is more often used in structural boat repairs and maintenance.

This specific type of epoxy can be used with a variety of materials including:

  • Fiberglass
  • Wood
  • PVC
  • Ceramic
  • Certain Metals
  • Concrete
  • Types of plastic



Pros and Cons of Marine Epoxy Resins




  • Strength and durability
  • Strong bonding and adhesion properties
  • Creates a bond to a variety of surfaces
  • When curing, it has little shrinkage
  • Damage and moisture resistant
  • Has fewer toxic hardeners
  • The epoxy has a long shelf-life



  • Product is expensive
  • Has low resistance to UV
  • May not bond effectively with a Gelcoat
  • While applying, it might be susceptible to environmental changes
  • You need to be extremely precise when mixing the resin and hardener



Casting Resin

Casting resin is used for casting molds, it is especially popular in making jewelry. The resin is thinner than your coating resin and has a variety of mixing ratios for different applications. You can work longer with the epoxy resin because it has a slow curing time. The casting epoxy resins can be used for industrial applications. For example:

  • Enclosing items
  • Filling in gaps or spaces in wood
  • Laminating of surfaces



Coating Resin

As the name implies, the resin is used for coating objects and can provide a surface for ceilings and floors. The resin helps to bond, coat, and seal objects. The resin is thicker than the casting resin and has a faster curing time. The coating resin usually also has easier mixing ratios.

The Epoxy coating resin usually supplies a clear finish, which can be used for things like:

  • Surfboards or a boat deck
  • Overlaying of furniture and other objects


how to repair epoxy resin countertops



UV Resistant Marine Grade Epoxy Resins

The epoxy, by itself, does not come with UV resistant properties. UV Resin is UV resistant, usually have an additive included. The UV additive is added to help prevent any yellowing of the resin over time.



There are UV Resistant Marine Grade Epoxy Resins available, which provides a longer duration of its non-yellowing effect. The UV resin is an excellent product to use for boat building applications as well as in the process of manufacturing fiberglass. UV resins are also used for smaller projects such as in the making of resin jewelry. The resin is also excellent in sealing small areas and works best as an epoxy resin adhesive.


UV Resistant Epoxy Pros and Cons



  • Fast curing time with the use of UV light.
  • There is no wearisome mixing involved
  • The resin has a longer processing time, so no need to rush



  • The product is more expensive than regular epoxy resin
  • The shelf-life of UV Resin is short, 6 months.
  • You can only apply thin layers of UV Resin, and you require several 3mm-4mm layers.
  • For the curing process to work effectively, you need a UV lamp.



Polyester Resin

This consists of unsaturated synthetic resins, which can be composed of a variety of different polyesters. Polyester resin is a major player within the composite industry.


Polyester Resin Applications

The polyester resin has many applications and can be used in many different types of projects. The resin is popular in the boat building industry and in repairing plastic items. Some of the more popular applications include the sealing of things like Jacuzzis and swimming pools. The product can also be used in various outdoor construction projects that require weather-resistant properties.

boat epoxy


Polyester Resin Pros and Cons




  • Polyester resin is a lot more affordable
  • You can determine the processing time by adding more or less hardener to the polyester resin. The weighing and measuring must be done accurately for a good result.
  • The design time is more flexible
  • You have your choice of reinforcing fabric for your building projects. Glass fiber mats or fabrics etc.



  • During processing, there is a definite odor
  • When compared to epoxy resin, the polyester resin falls short in many areas. Polyester resin is less water-resistant and durable.
  • Polyester resin does not bond to smooth surfaces such as glass or metal.
  • High shrinkage rate



Polyurethane Resin

Polyurethane resin is also a synthetic resin and a type of plastic. The resin is very versatile as it can be used in a variety of applications. The resin can be altered to form materials that are pliable or into something more rigid or hard. In most cases, the polyurethane comes in liquid form, which can then be poured into molds. Additives and fillers can also be added to the polyurethane resin, which can produce the properties you want in your end product.


Polyurethane Resin Applications

As mentioned, the resin is versatile and can be used in both industrial as well as by those at home. Here are a few applications for polyurethane resin:

  • Paints can be created from Polyurethane resin, as well as adhesives and other coatings
  • Casting tires and mold casting
  • Encapsulating electronic components and parts
  • Production of foam
  • Floor coatings


Polyurethane Resin Pros and Cons



  • Easy to work with
  • Has a workable viscosity, which helps to cast and shape it as desired.
  • The resin easily accepts a variety of additives and fillers
  • Little shrinkage occurs during the curing time
  • After curing, it has a high resistance to heat
  • You do not have to wait long to de-mold objects
  • Hardens quickly



  • You need to include additives to increase its UV resistance
  • After curing, you cannot weld it.
  • There are emissions or odors during the curing period
  • Adhesion properties are not as good as the epoxy resin
  • The resin is moisture sensitive, which reduces its durability



Marine Epoxy Paint

To finish off your boat repair or maintenance, you need to make it look good with some marine epoxy paint. Most paints are formulated to be effective for exterior applications, especially for marine environments. The paints usually add a layer of protection, water-resistance and can handle extreme conditions.

You will need to fist clean your surface you wish to paint. You will need to sand the clear marine epoxy until it becomes dull and wipe the surface. Then apply the marine epoxy primer, this takes a couple of layers. Finally, add your marine epoxy paint over the primer. Make sure to add a minimum of two layers of paint.

marine epoxy paints

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